MonteCarloSS.com

EFI Options

Posted By: Rick Hodgkins

EFI Options - 08/22/21 06:40 PM

Looking for EFI options.
The original 5.0 is coming out and have a new 5.7 roller cam crate motor with mechanical fuel pump option if desired.
Have a pair of aluminum 63cc L98 Corvette heads going on.
Not sure if I'm going to put a new carb on the original aluminum intake or an EFI system on it, but this mongrel electronic carb/system is GONE off the new engine.
What is the simplest fuel management system to install without dropping the tank?
This not a street racer, but its time has come for a little upgrade.
All advice and personal experiences on this are welcome.
Thank you
Posted By: BadSS

Re: EFI Options - 08/22/21 11:15 PM

I’ve been tuning and building cars for a long time - well,, not so much here lately. Anyway, tuned many computer controlled carbs back in the day (stock 305 to 500+HP 406). I’m going to be that guy and can tell you a properly running electronic carb with a few minor tricks WILL run as good or better than a vacuum 750 Holley and get better gas mileage on most mild to moderately powered 350s. The problem is, there probably isn’t someone local to you that can work on them and there is a learning curve that most won’t want to pursue by doing it yourself. The good news is though, there a number of people on the board that have used a few places that have rebuilt the electronic carb with good results – if you can be persuaded or convinced to go that route.

Check out this recent thread.
http://www.montecarloss.com/community/ubbthreads.php?ubb=showflat&Number=1071405&page=1

As far as fuel injection, the 4-barrel throttle body injection systems are a bit of a step up from the CCC, but I personally wouldn’t go through the hassle of converting from a CCC on anything around and under 400HP. Multiport Injection is by far the better choice, even a TPI conversion using the electronics and possibly a different manifold (if maximum performance is needed) would be a good choice. If going multiport, as far as dropping the fuel tank, I think the easiest conversion is using one of Holley’s Retro Modules that replace the stock sending unit. It requires dropping the tank, which isn’t that hard and appears to me to be a better option than most. I probably would be mindful of the fuel level and not run below 1/4 tank, unless you spend another $180 or so on an EFI replacement G-body tank.
https://www.holley.com/products/fuel_systems/fuel_tanks/muscle_car_efi_modules/parts/12-306
Posted By: Rick Hodgkins

Re: EFI Options - 08/23/21 03:08 AM

A little back ground on this and myself.

When I got this car I noticed the fender mounted map sensor before I noticed the E4MC carb.
The map sensor didn't have a vac hose supporting it, which I added figuring it needed one.
I am very well schooled on conventional carbs and Rochester Qjets and EFI theory as a marine tech/business owner.
This one kinda threw me, but ordered the correct kit for it to freshen it up.
When I hear owners say they are ripping out a TBI or TPI management system to go carb cause they don't speak the language or understand it I cringe the same way I do when somebody refers to a Qjet as a Quadrabog if you know what I mean.
The car has forever thrown a service code on deceleration and not having a scan tool for it took it to a local well known shop to isolate the problem who specializes in automotive diagnostics.
He did say the TPI ref voltage was stuck on 5 and not moving prompting me to put a new sensor in over the winter but offered no other reason for the service light.
This did not cure the code and made the engine unstable, its currently unplugged and running pretty well but has an off idle hesitation.
I jumped the data port plug and blinked a code 24 I believe which came up as a trans speed sensor which is connected at the speedometer, ordered and replaced with nos with no change to the code.
So without a scan tool I can read during the lamp on time, I'm kind of stuck with that along with the lack of techs that know this particular system.
This 305 runs pretty good with 85k, but has a small leak at the pan front/rear gasket, not sure but small.
I initially got this new engine to replace the engine in my 88 IROC, but that car is so pure I'm leaning towards a freshen up rather than replacement.
Any assistance guys here can offer regarding tuning I will follow, but just figured where this is kind of a transition mongrel between straight up carburetor and EFI, I'd start fresh with an EFI upgrade is all.
If I can make this fuel management system work well I will leave it and in the mean while do some reading on the links you posted.
Thanks for the help on this, Rick
Posted By: BadSS

Re: EFI Options - 08/23/21 04:23 AM

Check out this thread for some scanner info - invaluable when troubleshooting these electronic systems.
http://www.montecarloss.com/community/ubbthreads.php?ubb=showflat&Number=1071511

Here's the link to the scanner Brent is using ($75)
http://www.1320electronics.com/12pin_ALDL_BT_MK2.html

Looks like there is a used Brainmaster 3250 on eBay right now also.
Posted By: Rick Hodgkins

Re: EFI Options - 08/23/21 12:15 PM

Which one would you chose of the two?
tx r
Posted By: 88ssBrent

Re: EFI Options - 08/23/21 02:30 PM

The most valuable things for tuning, troubleshooting, and understanding the ccc that i have found is the GM service manual for your car and year, this forum, 3rdgen.org has some good ccc info, cliffs high performance quadrajet forum has a little ccc info, Doug Roes quadrajet book touches on it some, cliffs book doesn't touch on ccc at all.

This is a link to the service manual and I recommend getting the electrical supplement with it. Once again make sure its for your model year, mine is an 88.

https://www.ebay.com/itm/1988-GM-Fa...46890.l49286&mkrid=711-127632-2357-0

This manual and this forum will have all the info you need on the ccc. The manual is invaluable.

I started using just a used cheap ebay dwell meter to check the mixture control but I needed more so I started wanting to dig in more. I searched for a brainmaster but ran across 1320 electronics device. John the owner built an app for it so the device is bluetooth and you can watch everything on your phone, app is ALDLSCAN. Here is a few screenshots of 3 of the 5 live screens there is no info there because car is not connected.

[Linked Image]
[Linked Image]
[Linked Image]

It also has the capabilities to datalog. Remember the baud rate is slow and you are dealing with 1980's technology but this is one of the datalog screens. I have my a/f ratio gauge going to the spare channel to the right. This would be a quick wot pull.

[Linked Image]

Another one of my old datalogs.
[Linked Image]

I touch on some of my ccc tuning in my build thread on this forum. Now I think I'm around 350 h.p. with my 305 and plan to dyno it this winter. I run 100%, 93 gas but my car fires with a flick of a switch and my a/f is spot on from idle to wide open throttle. At cruise it stays between 14.5 to 15 a/f.

https://youtu.be/eiKtI-UGMsA

If you stay with the ccc I like using cliffs parts on rebuilds.
Posted By: Rick Hodgkins

Re: EFI Options - 08/23/21 04:46 PM

So a quick peek at this I see temp, are there both analog and digital sensors in this engine?
I also see speed which has me wondering about running changes made over the years.
Mine may be older as a reason.
Good info, thanks
r
Posted By: 88ssBrent

Re: EFI Options - 08/23/21 05:35 PM

Yes, temp for the ccc comes from sensor in the water neck, temp for dash gauge comes from water jacket in head on drivers side atleast on 88 and I would think the same on all monte carlo ss. The vss if I remember correctly is an optical reader located in speedo head i think its what sends speed signal to computer for Trans lockup and the cable from the trans goes to the speedometer gauge. There were a few changes to the computer in 87 i think was the year but it was not much. The file i use is for 84 up ccc so im willing to bet as long as your car is intact everything im speaking of is there or atleast should be.
Posted By: 88ssBrent

Re: EFI Options - 08/23/21 05:55 PM

Gm training videos for the ccc it says 81-83 but it does apply to ours.
Part 1 https://youtu.be/8jGqIBAUnMY
Part 2 https://youtu.be/vDStPuQyo_Q
Part 3 https://youtu.be/OVrvSDuFOjM
Part 4 https://youtu.be/wbscqaLYNjw

If you know quadrajets and efi theory you should be good to go. Also you can look into burned eprom chips from member bitflipper for the ccc helps with a few things depending on your build if you decide to stay ccc but not needed, as Kevin (BADSS) said the ccc is more than capable for some pretty good h.p. Also know Lance (SSlance) used his on a 383 and Bob (mmc427ss) used the ccc on his 427. At the end of the day you will just need to decide whats best for you as far as carb or efi.
Posted By: SSLance

Re: EFI Options - 08/23/21 07:15 PM

I waited forever to do my EFI swap, because I wanted to make sure I did it right. The fuel pump, tank pickup being my biggest concern. I ended up custom building the tank I needed and it works perfectly...but certainly not a bolt in solution. Once you get the fuel pump portion figured out, the rest of the EFI setup is fairly simple. I went with Holley Terminator 4 bbl throttle body but now that there is a multiport intake that works with vortec heads, I'd go that route if doing it again. But yes, it's awesome once you get it dialed in. The Holley software is super easy to deal with and I know a guy that can remote tune it to make it run as smooth as a 5th gen Camaro...
Posted By: Rick Hodgkins

Re: EFI Options - 08/23/21 07:56 PM

I really appreciate all the input on this.
I am a stock kind of guy and would rather keep it that way aside from wanting the 5.7 in there.
This discussion has changed my mind over the EFI I think.
The car came at me while looking for a 69 442 which was turning up junk or super high numbers and I bought it.
Meanwhile last year about this time that 442 popped up and yup now I have 3 of them running me ragged.
The resto was mainly cosmetic but I did a 2.5" SS exhaust first cause I had to and its got flow masters that sound great.
This is the start to finish album on my FB page, it was a long way back for this one, but still has most of the original paint.
https://www.facebook.com/media/set/?set=a.10219216671381632&type=3
Posted By: Rick Hodgkins

Re: EFI Options - 08/23/21 09:05 PM

OK, So I found the manuals, got the 87 supplement though.
Hoping for the best with the supplement.
Tried to call and order the BT scanner but called due to PP acct.
Will try again tomorrow.
Posted By: Rick Hodgkins

Re: EFI Options - 08/23/21 09:11 PM

Originally Posted by 88ssBrent
Yes, temp for the ccc comes from sensor in the water neck, temp for dash gauge comes from water jacket in head on drivers side atleast on 88 and I would think the same on all monte carlo ss. The vss if I remember correctly is an optical reader located in speedo head i think its what sends speed signal to computer for Trans lockup and the cable from the trans goes to the speedometer gauge. There were a few changes to the computer in 87 i think was the year but it was not much. The file i use is for 84 up ccc so im willing to bet as long as your car is intact everything im speaking of is there or atleast should be.

Its all starting to connect now.
That code 24 was for that speed sensor, but no change.
Just knowing its tied in now makes sense.
My brain is still seeing the 400 olds, yes the therm sensor is on that engine.
Its gotta be something stupid, for a cammed 305 it runs excellent all around.
Posted By: 88ssBrent

Re: EFI Options - 08/23/21 09:49 PM

Originally Posted by Rick Hodgkins
OK, So I found the manuals, got the 87 supplement though.
Hoping for the best with the supplement.
Tried to call and order the BT scanner but called due to PP acct.
Will try again tomorrow.


Just for your info 1320 electronics is a 1 man show and its his side gig. Any time I have left a message or email he usually returns the call or emails back after 6 or 7 eastern time.
Posted By: Hunter79764

Re: EFI Options - 08/23/21 09:51 PM

My $.02, I think your two best options are:
A. Keep the factory stuff and tune it up right
B. Go with a Holley EFI setup (pick your poison on which features and budget you want)

Factory system is complicated but simple, if that makes sense, and the answers can all be found on here, in books, or from a few calls to some smart guys. You can make the system work well and keep all of your functionality like proper transmission function and check engine systems.
For Aftermarket EFI, I'm not seeing where anybody has it figured out as well as Holley. Some of the others may be relatively simple and function well enough, but either they end up being not nearly as simple as they are sold to be, or not nearly as adaptable and capable as they should be. Holley seems to hit it well at the different levels, and the software by all accounts is the easiest to use for beginners and pros alike. You will run into problems that you will have to decide how to fix (fuel pump choice, fuel line connections, cable routing, transmission lockup, cruise control, etc.). None of those have a simple answer, you will need to consider what you want out of it and go from there. none are insurmountable, but they are all personal and will require some looking.

Of course there are other options if you wanted, like a custom port setup with MegaSquirt or a factory TBI retrofit, but it doesn't sound like that is what you are looking for at all. Old school carbs can be an option if you have experience setting them up, but you will still have issues to overcome like the transmission lockup (and TV cable on an aftermarket carb - that catches a lot of folks with a burned up transmission from a wonky bracket etc), cruise control, etc. Again, nothing crazy but there's more to it that just cutting some wires and throwing a double pumper out of the Jegs catalog on it.


Since you specifically asked about the fuel pump, avoid the "fuel command center" from FITech, it is overcomplicated and overpriced, and doesn't work the way it is described. External fuel pumps are loud and relatively unreliable, but the factory EFI tanks and hanger/pump assemblies are cheap and easy on these cars. Dropping the tank is easy, run high pressure fuel line as needed, and either run to a regulator in your EFI system or to a "Corvette Regulator" mounted somewhere reasonable (and I always vote as close to the engine as possible for best control). Look on RockAuto for a tank and hanger/sender for an '85+ Monte with a 4.3l or something like an '88 Grand National, then swap the pump for an appropriate aftermarket high pressure/high flow pump for $150 and be done.
Posted By: Travis Jones

Re: EFI Options - 08/24/21 07:51 PM

For the cost of the EFI system you could do a "free" efi swap with an LS based engine.

its kind of silly to spend the money on a standalone EFI kit when a complete motor with an EFI system can be had for about $500...
Posted By: SSLance

Re: EFI Options - 08/25/21 04:56 PM

+headers
+exhaust
+new transmission
+new driveshaft
+electric fan setup
+new air intake setup

Shall I go on? laugh
Posted By: Travis Jones

Re: EFI Options - 08/26/21 03:24 PM

Originally Posted by SSLance
+headers
+exhaust
+new transmission
+new driveshaft
+electric fan setup
+new air intake setup

Shall I go on? laugh


Headers - $200 (even with stock truck manifolds the MY2000+ 5.3 was rated at 285hp)
Exhaust ~ $200 (assuming you have a welder or a buddy with a welder)
You can use any GM old auto trans for $60 with a flexplate spacer a little ingenuity on the kickdown/TV setup/vacuum modulator, I ran my 200-4r for a few years with my LQ4. Granted you probably want a built transmission for anything making significant power over stock.
If you're not running an electric fan setup in 2021, you're either concerned with keeping your car all original so engine upgrades aren't your thing, or you're an idiot. (EFI/Carbed/LS/SBC/BBC even a Ferrari engine swap you should ditch the power and response robbing mechanical fan)
Air intake setup $90 (really you should try to get cold air into any engine, but the EFI system will pull timing if your IAT's are too high)
engine Mounts ~150
Oil pan ~ $350 (I mean technically the truck pan fits, but its risky as low as it hangs)
and the rest of the fuel system is nearly identical between an EFI system and an LS. so the costs are a wash.

A 5.3 LS is the cheapest available cam away from making a legitimate 420 hp, you can make more if you choose a slightly better cam. The rest of the engine can be untouched

Sure there are articles likes this one https://www.motortrend.com/news/0611em-vortec-small-block/ which show a "$3500" 447HP small block but then you see the article was written in 2006 and now that's nearly $5000. Then there's these type of articles, which show a $500 junkyard motor, and $500 worth of cam and valve springs making 467 https://www.cpgnation.com/the-100-horsepower-upgrade-cam-only-5-3l-test/ (both are tested with headers and an electric waterpump so the cost of headers/WP is a moot point)

Unless you are a class limited, there is not a single practical reason put a dime into a Gen I SBC in this day and age. You're like folks in the late 50's still believing the flathead is a competitive or worthwhile engine to build. Because of the value, because of the known results in my mind its borderline irresponsible to recommend doing anything other than an LS in one of these cars because it is so easy and cheap. Either keep the CCC system and the L69 and enjoy the horsepower of the 80's or rip it out and replace it with an LS, a motor actually worth your time and money.

Shall I go on?
Posted By: Buick Runner

Re: EFI Options - 08/27/21 12:09 AM

Originally Posted by Travis Jones
For the cost of the EFI system you could do a "free" efi swap with an LS based engine.

its kind of silly to spend the money on a standalone EFI kit when a complete motor with an EFI system can be had for about $500...


Depends on the area, some places you can't even buy a bare LS engine for less than 1k yet alone a complete running one with all the many accessories it needs to run. Cheap LS engines are fast becoming unicorns. Maybe too many people blowing them up with cheap Ebay turbos exhausting the supply.

Really, in this day and age its not worth putting a dime into G bodies when you can go buy a used factory powered LS car which is going to be all around far better car for less than updating a 80's downsized granny car. Even with an LS swap a g body is still an outdated 60's based design that will horribly hamper your LS motor withouf major and expensive upgrades to the frame, body, suspension, brakes, etc.
Posted By: Rick Hodgkins

Re: EFI Options - 08/27/21 03:49 PM

Really not a swap fan, more of a retro type.
Its a cruiser, not a street car.
Not looking to wreck it or spend time in court.
Just thought given the leaks I'd use this new motor I already own.
The advice to keep the CCC is taken, manuals on the way.
The 5.0 actually runs well as it sits, but want it tight with no leaks.
If its gotta come out, may as well use this motor I have is all.
Posted By: Hunter79764

Re: EFI Options - 08/27/21 08:21 PM

Sounds like a plan thumbs

Lots of opinions on LS vs CCC vs SBC vs whatever, ultimately it is your car, your choice, and your enjoyment that counts.
Posted By: BadSS

Re: EFI Options - 08/27/21 10:43 PM

Originally Posted by Hunter79764
Sounds like a plan thumbs

Lots of opinions on LS vs CCC vs SBC vs whatever, ultimately it is your car, your choice, and your enjoyment that counts.


I'll second that!!

Good luck with the engine swap - keep us posted on how it's going.
Posted By: 88ssBrent

Re: EFI Options - 08/27/21 11:49 PM

I have found thats its easy to get caught up in what other people think you need and get a person away from what they truly want. A person has to be honest with themselves on how they want to use their car and what is important to them. Its great that we all have so many avenues to explore, it sure would be boring if we all had the same thing.
Posted By: 200kSS

Re: EFI Options - 08/29/21 01:28 AM

"Shall I go on?"

Yes please. Which front accessory drive system and intake are you using for this mythical 5.3? Does your plan keep the working cruise control, a/c and factory gauges?
Posted By: Rick Hodgkins

Re: EFI Options - 08/29/21 10:24 PM


Originally Posted by 88ssBrent
Originally Posted by Rick Hodgkins
OK, So I found the manuals, got the 87 supplement though.
Hoping for the best with the supplement.
Tried to call and order the BT scanner but called due to PP acct.
Will try again tomorrow.


Just for your info 1320 electronics is a 1 man show and its his side gig. Any time I have left a message or email he usually returns the call or emails back after 6 or 7 eastern time.


I tried to order online, but it was NIS
Sent email
Maybe its just these times we're in taking its toll, I totally get it.
Posted By: Rick Hodgkins

Re: EFI Options - 08/29/21 10:26 PM

Originally Posted by Hunter79764
Sounds like a plan thumbs

Lots of opinions on LS vs CCC vs SBC vs whatever, ultimately it is your car, your choice, and your enjoyment that counts.

Thank you
I guess the standing line is these cars are only virgins once.
I'd rather keep that than rape it I guess.
Posted By: Travis Jones

Re: EFI Options - 08/30/21 02:08 AM

Originally Posted by 200kSS
"Shall I go on?"

Yes please. Which front accessory drive system and intake are you using for this mythical 5.3? Does your plan keep the working cruise control, a/c and factory gauges?


Sure the factory truck intake accessories work perfectly fine in the G-body without modification with the Holley engine mount brackets. (the truck intake actually makes more power and torque than the early LS1). I've been running them for years. All of my factory gauges work. For temp you use $25 temp sender from a 1998 firebird with three prongs, you connect that to the temp sensor wire that comes through the fire wall to the bottom prong. For the oil pressure you have two options you can buy an $18 m16x1.5 to 1/8npt adapter where the LS factory oil pressure sensor goes, or you can buy a $25 oil cooler block off plate with an 1/8 npt port for the factory gauge. Harnesses have a tach output wire, you tie that to the beige/brown wire coming through the firewall. You can use the 200-4r and the mechanical speedometer on drive by cable applications. Or a TH350 or TH400, if you want to run a more modern trans that outputs a VSS signal, you can get a converter box, they are a little pricey at $400 or you can get the guts of an early 90's G20 van (the old body style) speedometer and install it into your cluster with the Monte faceplate. If you run a Drive by wire harness you can integrate the factory cruise control buttons on the stalk into the harness, I haven't tried drive by cable cruise, but I'm sure its possible. As for AC, you can get a high mount bracket to use the factory R4 compressor for $115, with a DBW throttle, the computer will compensate for the added load, for DBW you could use the factory high idle solenoid, if you wanted, granted you'd have to make your own bracket. On a cutlass/regal where the compressor is on the passenger side, I believe the factory lines work. On a monte you'll need custom AC lines because you're switching the side of the compressor, but the rest will work. Does the factory AC work on any of these old cars? They pretty much all need attention at this point.

Does that satisfy your curiosity?
Posted By: Masshole_Monte

Re: EFI Options - 09/03/21 05:14 AM

I have a 6.0 in my SS with the holley 550 878 sniper stealth.works awesome.
Posted By: FrankOC

Re: EFI Options - 09/03/21 02:02 PM

Rick, car is looking great and I see you used the 85 only material when redoing your upholstery. FYI - if your oil pan is the source of the leak, you can change the oil pan gasket without pulling the engine. I did it and it's not a bad job at all.
Posted By: Buick Runner

Re: EFI Options - 09/03/21 03:20 PM

The CCC is a pretty good system. Bad thing about them is that many POs butcherd them up for various reasons. They also really dislike vacuum leaks but so does most fuel systems including EFI.
Posted By: Rick Hodgkins

Re: EFI Options - 09/10/21 12:08 PM

Originally Posted by FrankOC
Rick, car is looking great and I see you used the 85 only material when redoing your upholstery. FYI - if your oil pan is the source of the leak, you can change the oil pan gasket without pulling the engine. I did it and it's not a bad job at all.


Thanks for the props, car gets a lot of love. Most of the paint is original also.
I imagine the engine must be lifted off the mount pedestals to allow this access.
Does anyone if this had an o2 sensor/s from the factory?
When I got it the exhaust system was wasted and I had a stainless system put on with Flowmasters.
Not being sure where I was going with the engine, I had them tie onto the original pipes because they were scared of the flange bolts breaking.

I did get the Brainmaster scanner complete with case, guide and modules as I couldn't connect with 1320 electronics.
I did get both manuals for the engine as well.
Kinda anxious to plug in and see what comes back.

@ Buick Runner, noting the map had no hose to it, I do suspect the hackers have done their magic here.
Posted By: Buick Runner

Re: EFI Options - 09/10/21 03:30 PM

Yes these cars did originally have O2 sensors from the factory and are required for the CCC system to function. They do sell weld on bungs for O2 sensors.
Posted By: Rick Hodgkins

Re: EFI Options - 09/10/21 03:52 PM

Originally Posted by Buick Runner
Yes these cars did originally have O2 sensors from the factory and are required for the CCC system to function. They do sell weld on bungs for O2 sensors.


Cats or no?
Matter or not?
For sure an x pipe is gonna happen with new manifold connections this winter.
Posted By: FrankOC

Re: EFI Options - 09/10/21 04:00 PM

Originally Posted by Rick Hodgkins
Originally Posted by FrankOC
Rick, car is looking great and I see you used the 85 only material when redoing your upholstery. FYI - if your oil pan is the source of the leak, you can change the oil pan gasket without pulling the engine. I did it and it's not a bad job at all.


Thanks for the props, car gets a lot of love. Most of the paint is original also.
I imagine the engine must be lifted off the mount pedestals to allow this access.


It does. Remove the distributor cap, unbolt the motor mounts, then jack up the front of the motor a couple inches.
Posted By: stew'86MCSS396

Re: EFI Options - 09/10/21 10:21 PM

Originally Posted by Rick Hodgkins
Originally Posted by FrankOC
Rick, car is looking great and I see you used the 85 only material when redoing your upholstery. FYI - if your oil pan is the source of the leak, you can change the oil pan gasket without pulling the engine. I did it and it's not a bad job at all.


Thanks for the props, car gets a lot of love. Most of the paint is original also.
I imagine the engine must be lifted off the mount pedestals to allow this access.
Does anyone if this had an o2 sensor/s from the factory?
When I got it the exhaust system was wasted and I had a stainless system put on with Flowmasters.
Not being sure where I was going with the engine, I had them tie onto the original pipes because they were scared of the flange bolts breaking.

I did get the Brainmaster scanner complete with case, guide and modules as I couldn't connect with 1320 electronics.
I did get both manuals for the engine as well.
Kinda anxious to plug in and see what comes back.

@ Buick Runner, noting the map had no hose to it, I do suspect the hackers have done their magic here.

You talking about the sensor/bracket right behind the coolant over flow tank? Someone correct me if I'm wrong, that's a baro sensor and measures atmospheric pressure. There shouldn't be any vacuum hose hooked up to it.
Posted By: Rick Hodgkins

Re: EFI Options - 09/10/21 11:18 PM

Its a MAP or Manifold Absolute Pressure sensor which is an electronic vacuum sensor to tell the ECU vacuum level based on load.
Posted By: stew'86MCSS396

Re: EFI Options - 09/11/21 12:09 AM

Originally Posted by Rick Hodgkins
Its a MAP or Manifold Absolute Pressure sensor which is an electronic vacuum sensor to tell the ECU vacuum level based on load.

Seriously? Although not with 100% certainty, I told you what it is. Your MAP/vacuum sensor is located between the distributor and EGR valve. I've parted an '84 EC and they had that same BARO sensor zip tied to the wires under the dash with only the electrical connector hooked up and NO vacuum hose.
Posted By: Rick Hodgkins

Re: EFI Options - 09/11/21 03:05 AM

On this 85 the map/baro sensor is fender mounted as shown in this picture behind the expansion tank.
I've never seen one not connected to manifold vacuum.
https://www.facebook.com/photo/?fbid=10219216673661689&set=a.10219216671381632
Posted By: Buick Runner

Re: EFI Options - 09/11/21 03:20 AM

The CCC layout changed over the years. Early years the MAP sensor was mounted on the passenger fender with a long vacuum line to the carb. Later years put the BARO sensor on the fender and moved the MAP sensor to the back of the intake manifold with a short vacuum line to the back of the carb.
Posted By: stew'86MCSS396

Re: EFI Options - 09/11/21 04:24 AM

Ahhhh...that clears up some confusion. This url has '85 in it but the sticker clearly shows 1983... https://www.opgi.com/product/image/OP/192810/decal-85-monte-carlo-emissions-50-us-l220282.jpg
Rick has a '85 sticker on his Facebook page^^^... Rick's '85 Emissions
Posted By: Rick Hodgkins

Re: EFI Options - 09/12/21 08:25 PM

I wasn't confused, its the most common map sensor GM makes and there was no vacuum hose supporting it on this car.
To the best of my knowledge the map and baro sensor are one in the same thing.
To have one tie wrapped and not connected to the engine makes absolutely no sense to me but I will listen first.
Posted By: MAP

Re: EFI Options - 09/12/21 09:43 PM

How pressure sensors work: https://www.avnet.com/wps/portal/ab...sure-sensors/measurement-types/absolute/

There's a chance that a disconnected (from engine vacuum, that is) sensor is being used to measure atmospheric pressure as a reference. It must be connected electronically, however. Otherwise, it's just a paperweight sitting underneath the hood...

MAP: "Manifold absolute pressure" (sensor.} "Barometric" (sensor.) Both detect pressures of gases and are functionally equivalent. The prefix "baro" is Greek for "weight."
Posted By: Hunter79764

Re: EFI Options - 09/13/21 01:41 PM

I've got a lot more experience with the TBI and EFI, but I think CCC and TBI shared a lot of GM logic, just different components to control. Based on my experience, early on, they took a reading of the manifold pressure AND a reading of the atmospheric pressure (barometer) and compared the two. since they are both just reading air pressure, it very easily could have been the same sensor used on multiple applications, one connected to a vac source and the other (in my case) sitting on the inner fender sampling atmospheric pressure. By comparing the two readings, you get a better picture of how much throttle you are really giving it. i.e., if you are at sea level and have 31 in Hg and you go WOT, the MAP sensor will ready pretty close to 30". But if you were just close to WOT, you might get 26" and not need as much enrichment as you get on the pre-programmed WOT tables. But the same car on a day with funny weather in Denver might have 26" be the highest reading possible, and you would want it to kick over to the WOT tables. Without a Baromoter reading to compare to, the computer can't tell the difference between those two scenarios. I suspected that after a few years, they figured out that the data gained with the Baromoter reading wasn't actually worth it and dropped it, but I did some googling and it looks like they actually got smarter in later years and started taking the MAP reading before the engine starts and using that value as the Baro setting for that drive cycle.

All that said, I couldn't tell you on yours if the sensor on the fender needs to be connected to vacuum or not. If you find another one near the manifold with a vac hose going to it already, then the other is likely the Baro sensor and needs to be vented to atmosphere.
Posted By: Rick Hodgkins

Re: EFI Options - 09/13/21 07:42 PM

The emissions decal does show it connected to a vacuum source but calling it a vacuum sensor.
I found the vac source missing when I got the car 2 years ago and put one on it.
It seems this as close as it gets to TBI short of pressurized fuel in my mind being it has a tps and ecu controlled metering rods.
I do speak the efi language but this mongrel is a bit outside of that in its own way I guess.
Thing is a weakling on top, but starts and accelerates pretty well short of a slight flat spot off idle.
Posted By: Hunter79764

Re: EFI Options - 09/13/21 08:13 PM

Yeah, it seems like the major difference between TBI and CCC is a couple of 14 psi injectors and some simplified diagnostics. I've yet to need a dwell meter for any of my TBI stuff, but it seems like you need a Brainmaster to do much on these CCC setups.
I had a 4.3 TBI in mine for 5 years, an 85 S10 with TBI 2.5 for 5 years before that, did a fair amount on a TBI 350 in my sister's Formula Firebird and another in Mom's Suburban, now I just picked up another 87 Suburban with TBI. The last 10 years has pretty much all been LS stuff though, so I'm having to dust off the TBI memory on this 87 until I get a 5.3 or 6.0 into it next year...

But anyway, good luck on this one, hope it gets sorted out for you.
Posted By: stew'86MCSS396

Re: EFI Options - 09/13/21 10:45 PM

Originally Posted by Rick Hodgkins
The emissions decal does show it connected to a vacuum source but calling it a vacuum sensor.
I found the vac source missing when I got the car 2 years ago and put one on it.
It seems this as close as it gets to TBI short of pressurized fuel in my mind being it has a tps and ecu controlled metering rods.
I do speak the efi language but this mongrel is a bit outside of that in its own way I guess.
Thing is a weakling on top, but starts and accelerates pretty well short of a slight flat spot off idle.

I still don't get it, on my '87 LG4, there's the same fender mounted sensor and also another one near the dizzy/EGR valve. The fender mounted one does not have a vacuum hose connected the way GM intended. The one on the engine near the dizzy/EGR valve suppose to be connected to a vacuum source, again the way GM intended.
Not my pic but something I found here:
[Linked Image]
Red scribblings, is this where yours didn't have a vacuum hose connected and you added it? Or are you saying yours doesn't have a vacuum sensor in this location? If I look at your Facebook pictures, it does appear there's a sensor on the engine but the picture gets pixelated when you blow it up. think

Originally Posted by Buick Runner
The CCC layout changed over the years. Early years the MAP sensor was mounted on the passenger fender with a long vacuum line to the carb. Later years put the BARO sensor on the fender and moved the MAP sensor to the back of the intake manifold with a short vacuum line to the back of the carb.

Certainly not unheard of that a crossover year you could get either configuration but I think I've established in an earlier post that your emissions sticker would indicate whether it's early fender or late engine mounted.
Posted By: MAP

Re: EFI Options - 09/14/21 08:13 PM

Hi Rick,

"Thing is a weakling on top, but starts and accelerates pretty well short of a slight flat spot off idle." It's been years for me, but that's exactly my recollection of the 305 as well. It dies on top because of its primitive intake manifold and mostly because of its awful, non-flowing heads. Chalk that design up to engineers working mostly in the dark prior to the BC (Before Computers) days of CFD (Computational Fluid Dynamics). They believed that the key to low emissions and good fuel economy was using restrictive heads that might have actually worked well for an engine of half the 305's displacement. The 350 with Corvette L98 heads (are you still planning on that swap?) will be a big improvement, but while those heads were fairly good back in the day (the mid-1980s), they're still restrictive by modern standards.

I like Travis' idea of an LS swap. I totally get the idea of keeping with the period-correct design of the original car, but in retrospect, just about everything relating to performance was totally constrained by 1960s design thinking. The factory's goals were transportation comfort for a family of four, good fuel economy, low production cost, and performance, in that order - with the last item of barely discernible consequence. For this reason, I feel no compunction whatsoever about raising the MCSS up to 2021 engineering standards.

But, not trying to twist your arm; that's just my opinion!
Posted By: Buick Runner

Re: EFI Options - 09/15/21 03:43 PM

Looks like some posters are proving this meme is right. [img]https://scontent-iad3-2.xx.fbcdn.ne...db5beae05a7a17d8e4246001&oe=6168DF6A[/img]

I don't have off idle bogs with my 305, and it screams pretty well. Generally off idle bogs are caused by having the throttle plates too far closed at idle. This throws off the timing of the idle and off idle ports which is a common tuner error.

TBI does not flow as well as E4ME Qjets, its another stopgap technology. The best factory TBI is the 9C1 police package TBI and even that still flows less than a CCC Qjet. The L69s in Montes are more choked down than the L69s in F bodies which had higher flowing aircleaners and exhausts for a 10 HP boost. Likely this was done for product marketing position purposes. Every product must fit in a position in the market.

Personally I would avoid putting a DBW engine in my G body. DBW has lots of issues such as less predictable response and that they are programed to go "lazy" over time to save gas. Its designed to decide what's best for you, a reduction of control and agency.

L98 heads only flow a little more than 305 heads, L98 at .5 lift flow 195, 305 416 heads at .5 lift flow 184, both are intake port readings.
Posted By: Rick Hodgkins

Re: EFI Options - 09/15/21 07:23 PM

I see classics raped with LS's and cringe honestly, but thats just me.
Not in a hurry, the fuel/elec on this is not right for sure.
Once I get it set up, things will probably change.
Hoping anyway
Posted By: MAP

Re: EFI Options - 09/15/21 10:38 PM

Despite your not-so-subtle insinuation, Buick, "some posters" isn't me. Anyone could invert the message in the cartoon and paint SBC-1 proponents in a similarly bone-headed light. LS engines aren't magic. Neither are SBC-1s. The former is simply a linear progression from the SBC-1 that benefitted enormously from computer-aided modeling and design, which is one of my specialties.

So I had to shake some cobwebs to get flow measurements on these heads but this seems to be a good source:

http://www.montecarloss.com/community/ubbthreads.php?ubb=showflat&Number=267425

I did some modest porting on a set of new aluminum L98 heads to about 215 cfm on the intake side as I recall and put them on a 350 that previously had 305 heads (same cam.) To say it woke up the engine would have been an understatement.

Of course, all of these 1980s (and prior) heads are poor-flowing by modern standards. On a 350, they all sign-off by about 5krpm. Any LS-era head would spank them...

Even so, Rick - about not wanting an LS in your car, totally understood and appreciated. But still not clear - are you contemplating a 350/L98 swap? If it were me, I'd spend a good chunk of time porting the L98s. It's not hard to get the intake up to about 230/240cfm, and a 350 really needs it.
Posted By: Buick Runner

Re: EFI Options - 09/16/21 05:00 AM

Actually it was meant to be a friendly jab at both you and Travis, didn't mean to get anyone upset. LS guys do tend to hijack SBC threads on car forums which is not always helpful which the linked meme refers to. The LS fan over enthusiasm can come across as annoying wither intentional or not. For a 350 I would rather have 350 heads too, I would just get a Vortec crate and be done.

Which 305 heads did you port out? There were several different 305 castings with some better than others. The swirl ports being the worst of the lot which thankfully MCSSs do not have. 305 heads should have larger valves installed for 350 use, did you install larger 1.94 valves? Stock 1.84 valves on 416 heads are sized for filling 305 cylinder volume, not 350 cylinder volume.

416 stock flow numbers https://www.thirdgen.org/forums/tech-general-engine/591429-stock-416-head-flow.html

L98 stock flow numbers https://www.corvetteforum.com/forum...um-head-flow-numbers.html#post1545504940

416 heads can be ported out to 240 / 190 which beats stock vortecs. https://www.thirdgen.org/forums/tech-general-engine/308973-vortec-heads-vs-my.html#post2429844

Granted Vortec heads are a better starting point for porting.

Frankly if a person wants true modern performance, then buy a modern car and be happy. A 40 year old granny mobile is not the best basis for a modern hotrod, or even a retro tech hotrod. IMHO, modern tech is overrated and has its shares of drawbacks like aforementioned DBW controls, yuck.
Posted By: Buick Runner

Re: EFI Options - 09/16/21 05:33 AM

Originally Posted by stew'86MCSS396
Originally Posted by Rick Hodgkins
The emissions decal does show it connected to a vacuum source but calling it a vacuum sensor.
I found the vac source missing when I got the car 2 years ago and put one on it.
It seems this as close as it gets to TBI short of pressurized fuel in my mind being it has a tps and ecu controlled metering rods.
I do speak the efi language but this mongrel is a bit outside of that in its own way I guess.
Thing is a weakling on top, but starts and accelerates pretty well short of a slight flat spot off idle.

I still don't get it, on my '87 LG4, there's the same fender mounted sensor and also another one near the dizzy/EGR valve. The fender mounted one does not have a vacuum hose connected the way GM intended. The one on the engine near the dizzy/EGR valve suppose to be connected to a vacuum source, again the way GM intended.
Not my pic but something I found here:
[Linked Image]
Red scribblings, is this where yours didn't have a vacuum hose connected and you added it? Or are you saying yours doesn't have a vacuum sensor in this location? If I look at your Facebook pictures, it does appear there's a sensor on the engine but the picture gets pixelated when you blow it up. think

Originally Posted by Buick Runner
The CCC layout changed over the years. Early years the MAP sensor was mounted on the passenger fender with a long vacuum line to the carb. Later years put the BARO sensor on the fender and moved the MAP sensor to the back of the intake manifold with a short vacuum line to the back of the carb.

Certainly not unheard of that a crossover year you could get either configuration but I think I've established in an earlier post that your emissions sticker would indicate whether it's early fender or late engine mounted.


Its possible for a car to have an incorrect emission label installed. Previous owners can do weird stuff to these cars or hire mechanics that do likewise.

Rick, the CCC is pretty simple to work on. With Qjets, the throttle blade position at idle can affect other areas. Too far closed causes an off idle bog, too far open and you get nozzle drip. Moreover, the idle mixture needles in the throttle body affect both idle and off idle mixtures while the idle air bleed valve in the airhorn affects just the base idle mixture. Set the idle mixture needles to 3 and 3/8 turns from lightly seated, then adjust the air bleed for correct dwell. Base ignition timing also affects idle quality.

As for top end power issues, check your fuel flow and secondary airvane tension adjustment. As I said before, Montes got restrictive single snorkel aircleaners to knock their power down by 10 HP so as not to upstage Camaros which got higher flowing twin snorkel aircleaners. My police packaged Crown Vic has 11 extra HP due to having a higher flowing aircleaner, air intake restrictions can really affect top end power.
Posted By: MAP

Re: EFI Options - 09/17/21 04:10 AM

Hi Buick,

OK - the clarification helped. The LS plug was not to annoy but to suggest a better and probably cheaper path to EFI delivery with more power, better economy, and modern reliability.

The heads I ported were fresh Corvette 350 aluminum L98 heads ordered from GM around 1988 as I recall. 1.94"/1.50". Magnesium valve covers. I did the usual mods everyone does: enlarge/smooth the bowl, narrow/streamline the valveguide boss, widen the intake port at the pushrod pinch-point. Frankly, I was surprised the flow came up as much as it did for so little work; too bad the original numbers are long gone in some forgotten notebook somewhere. I also remember the exhaust side came up fractionally even more, but again, too much time has passed for a clear recollection.

About modern performance in an old car: I believe in having them both. If I could take an MCSS body and wrap it around a Tesla, I'd do it in a heartbeat. With the A/G body, GM basically did as little as they could as quickly and as cheaply as they could to recover from the Middle East oil crisis. The goal at the time was an engine that would last only 75,000 miles, and performance was barely an afterthought. So no, I have no qualms whatsoever about trashing the dull engineering in that car and bringing it into the 2020s. And sorry, Buick, but I couldn't possibly disagree with you more about modern tech being overrated. In fact, what I see here is more the opposite: it's the old tech that's overrated.

But at the same time, I can see and respect Rick's desire to stay with more period-correct technology.
Posted By: Buick Runner

Re: EFI Options - 09/17/21 06:10 AM

I also could not disagree more with you that older tech is as bad as you claim. My 305 has 100k on the clock and still has excellent compression readings with little deviation between the readings. Before I swapped it into the Regal I had to pull a head to get a broken exhaust manifold bolt off and the cylinders on that bank still had hone marks and no ridge. Its not uncommon for 305s to last 300k. I also have a 70 year old tractor with original engine internals that runs like it was new.

One advantage I will give to modern tech is that it is often more forgiving of neglect than older tech. Then again new tech tuning is locked behind hefty software paywalls, requires a degree in electronics, as well as various obnoxious nanny and eco tech like DBW throttle to contend with. Overall, modern tech is far less servicable for hobbyists on purpose and it gets worse the newer and more modern it is. Most LS guys farm out most of the work rather than perform it themselves such as wiring and tuning but some car owners see that as a good thing.

But this is hijacking the OP's thread, we will just have to agree to disagree.
Posted By: Rick Hodgkins

Re: EFI Options - 09/17/21 02:24 PM

Not a hijack, great discussion.
Seen some LS jobs that really shined, some pretty sloppy.
IMHO a car is only a virgin once, after that its never the same as it rolled off the line.
Sure it matters to me and not to others, I get it.
Some gotta go 150 mph some are happy at half that.
The long term problem is hop ups are unless you upgrade the whole drive train and front end, its gonna let you down as things break that weren't designed for it.
When I pop the hood on a 40-50 year old car and see either a untouched original or meticulously restored engine its a turn on tbh.
We're not even touching on keeping the numbers correct, and that alone down the road WILL matter to purists.
I have 3 cars that are all original and near complete with this 69 442.
Is that a car that would have more or less value with an LS?
What would a buyer want more?
https://www.facebook.com/photo/?fbid=10221915165362295&set=a.10220823234824714
Posted By: Rick Hodgkins

Re: EFI Options - 09/17/21 02:31 PM

This 1971 MC was a complete frame off.
The engine bay was absolutely perfect in every detail, no runs, no drips no errors or grease.
What would you want more, that or one that had an LS slammed in there?
https://www.facebook.com/photo.php?...t=pb.1053952666.-2207520000..&type=3
Posted By: zelm86ss

Re: EFI Options - 09/17/21 03:58 PM

I'd take the 71 MC as it is!
Posted By: MAP

Re: EFI Options - 09/17/21 09:54 PM

Hi Rick - That 1971 is a beauty for sure! Glad you took the LS subtopic in the light it was intended. Buick - well, nah - forget it. You didn't take the LS subtopic in the light it was intended. We've been around this block at least a hundred times in different threads. Enjoy your world. Peace.
Posted By: Rick Hodgkins

Re: EFI Options - 09/18/21 02:06 PM

I do understand the reasons.
The LS is a strong engine costing far less than building a stroker or charging which will shorten the engines life.
If the original engine was puked that might be my direction also.
Posted By: Rick Hodgkins

Re: EFI Options - 09/23/21 11:27 PM

So interestingly enough with the scan tool hooked up I am getting 3 codes.
A 24, 36 and 42.
Also found the data stream pretty complete but found the engine temp sensor low, like 85-95 when the analog is reading 200.
I am getting map voltage reading changes, so its functioning it appears.
In kinda deep on another car atm, but feeling pretty good about the ccc system now, thanks for leading me on here guys.
Baby steps, but its all making a little more sense to me now vs before.
Posted By: AkronAero

Re: EFI Options - 09/23/21 11:58 PM

Rick - any chance the scanner is reading temp in centigrade? 200F is 93C?
Posted By: Rick Hodgkins

Re: EFI Options - 09/24/21 12:03 AM

Have to look again I guess, its a possibility.
The scanner is totally new to me at this point.
tx
Posted By: Rick Hodgkins

Re: EFI Options - 10/04/21 06:52 PM

Temp is in C yes, hard to read while driving lol.
Anyway Code 42 pointing at a bad distributor module, need to have it tested I guess.
It does go into closed loop, so the ECU is in control.

Internet saying code 36 is a mass air flow sensor problem, but thought that started with TPI and I don't see one on this engine unless its hidden.
Pretty straight forward induction through a normal air cleaner, no extra plumbing or wiring.
Another 36 is a crank position sensor which this doesn't have in the traditional SBC location behind balancer.
The other one was a 4T60E shifting error and it has a 200R trans.
Anybody followed this string before?
Posted By: 88ssBrent

Re: EFI Options - 10/04/21 07:57 PM

This is from my 88 manual so might not be the same for code 42 troubleshooting. Also there is no code 36 on a 88 monte so I wouldn't think it would be on any others. The manuals really help and any one that owns a monte should have one, they are invaulable.

[Linked Image]

[Linked Image]
Posted By: Rick Hodgkins

Re: EFI Options - 10/04/21 08:57 PM

Thanks Brent, I did get the manuals but car is at work manuals were at home.
There is definitely some control switching going on with the ecu.
Sometimes on cold start I get a service light and different idle speed.
Key off and on and lights out and the engine is running smoothly again.
I have not seen it go open loop where the controls are fixed once at temp.
I will follow this flow chart to the letter to figure this out and report.
Thanks for the assist
r
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