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#1054699 - 12/04/17 06:40 PM Re: Excessive MPG? [Re: ChasUno]  
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Ranger413 Offline
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Just picked up a Brain Master II for my Monte. For $40 off of Ebay, any info it can provide will be well worth the cost. Looking forward to giving it a try.




88 MCSS, all stock except for the wheels
#1054700 - 12/04/17 07:55 PM Re: Excessive MPG? [Re: ChasUno]  
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Richie Cat Offline
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Would you like to expand on that?
Copied Brain Master II and came up with "things".


83 SC, 355 w/TPI
#1054731 - 12/08/17 06:15 AM Re: Excessive MPG? [Re: Richie Cat]  
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ChasUno Offline
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Originally Posted by Richie Cat
Would you like to expand on that?
Copied Brain Master II and came up with "things".


Not quite sure what your question is, Richie Cat?

If you mean what is the Brain Master II, it's the dedicated scanner that can read all the CCC ECM sensors in real time, including fault codes. Here's a link to the scanner I bought:

https://www.ebay.com/itm/Alltest-Automotive-Diagnostic-Equipment-BrainMaster-II-Model-3240-/372124509796?_trksid=p2047675.l2557&ssPageName=STRK%3AMEBIDX%3AIT&nma=true&si=mZimOryjpJgVnsr48UoxhMdOe2g%253D&orig_cvip=true&rt=nc

From what I understand, it's the official scanner used by GM dealers when the cars were still being serviced by them. Very limited market for them now, as they only read GM (and some Isuzu) vehicles up to the late 80's, and with many people pulling out all the CCC stuff, there's even less market for them. However, for those of us still running CCC systems, it's an absolute godsend. Since I received mine I have been able to get a much better insight into what my engine is doing, including while the car is running and driving, which I wouldn't have been able to do without it.

I got mind for an absolute bargain price too, so a win/ win for me. If anyone still runs their CCC system, I strongly recommend getting one of these when they come up for sale at a decent price.


1986 Monte Carlo SS

[Linked Image]
#1054732 - 12/08/17 06:47 AM Re: Excessive MPG? [Re: ChasUno]  
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ChasUno Offline
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Further to update on my "tuning" efforts.

Firstly, it appears that my Quadrajet is completely original and unmessed with. All the blanking plugs/ covers were in place, therefore it appears that the carb is untouched since it left the factory in 1986. Unless it was replaced at some point, or rebuilt by someone who replaced the blanking plates/ plugs. As mentioned in a previous post, observing the MC Dwell on the Brainmaster showed the dwell to be on the low side, averaging approx. 23 degrees. I had to remove the IAB blanking plate to get to the adjusting screw, then I attempted to adjust it to increase the dwell. I ensured the engine was up to operating temperature and that the computer was in closed loop, then adjusted the IAB screw. I did get the dwell higher, though it was hard getting it much over 30 degrees (engine running at approx 600 rpm and transmission in drive). Eventually I got it averaging close to 30, though it tended to dip more into the mid to high 20's than low 30's. I have also purchased an analogue dwell meter, so once that's arrived I will try that and see how the readings compare. At the very least, I was able to adjust the MC dwell closer to 30 degrees and it's varying, which shows that the MC solenoid is working and trying to do its job.

One issue I am having is trying to get a stable TPS setting, it seems that the very slightest tweak on the TPS screw causes the reading to jump either way considerably. The Factory Service Manual recommends setting it with the ignition on and the engine not running. However, if I do it this way, then the TPS base setting goes much higher when the engine is started and running. It also appears to go higher when warm after setting it. If I set it with the engine running (600rpm, in Drive), it's also very hard to try and get it set to 0.48v. And when I do get it close to 0.48v, touching the accelerator and releasing it, the reading doesn't go straight back to 0.48v, instead it seems to hover at higher readings (i.e. 0.64v) and slowly drops to somewhere near the base setting. Then if I turn the engine off and keep reading the TPS, it will continue to slowly drop below 0.48v as the engine cools.

Having never worked with a TPS prior to getting my MCSS I am not familiar with how they are supposed to behave. I replaced the TPS sensor a few months back, now I am wondering if perhaps the unit I fitted is faulty, or I didn't fit it quite right? Or is the type of behavior I described above regarded as normal? Or, maybe the throttle shafts are just worn making it hard for the linkages to stay stable?


Last edited by ChasUno; 12/08/17 06:49 AM.

1986 Monte Carlo SS

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#1054735 - 12/08/17 06:57 PM Re: Excessive MPG? [Re: ChasUno]  
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mmc427ss Offline
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As far as dwell goes you are looking for 28-32 varying back and forth at idle. Looking at the threads for the IAB you should see about 7 threads showing in the hole. When you deviate much from that you will need to tweak on the idle mixture screws.

The TPS voltage may vary but you are only interested in shooting for that .48 volts when the engine is at normal temp and idling. Yes throttle shaft slop, weak carb return springs may cause erratic voltage. But varying voltage a tenth or less shouldn't be a problem.
Bob

#1054817 - 12/14/17 06:29 AM Re: Excessive MPG? [Re: ChasUno]  
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ChasUno Offline
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Thanks as always Bob, for your input and sharing of experience and wisdom. Hopefully I will get closer to getting my MCSS running akin to a Swiss Watch. Maybe!

Anyhow, another fuel up and another update. I didn't do so well with the last tank of gas, though I suspect there's a number of reasons for that. Down to 11.7mpg, though not as bad as the lowest I got. Here's the latest Fuelly result:

[Linked Image]

A number of reasons for the drop in mpg compared with the last tank - firstly, I was doing a lot of tuning with the car idling in drive, so that likely used extra fuel. Also, I was still trying to get the mixture control solenoid to dwell around 30 degrees and it seemed to be dropping more down in the low to mid twenties at idle. As a result it spend a lot of the last tank running rich. Also, one time I forgot to plug the electric choke connector back in so on one short drive the idle revs were sky high and it was choked like crazy. Oops!

As also mentioned above, I was having a nightmare trying to get the TPS to give a stable reading at idle. Furthermore, I think I discovered another issue with regards to the TCC lock up system. I had noticed that it didn't seem to want to go into lock up as easily as it did, and when it did it would come in and out of it at random if I was below 55mph. At the same time this became apparent, I also noticed that when engaging cruise control the car would surge back and forth, many times and at random, even though the speed had been set. I thought that maybe the cruise control system had a fault in it somewhere, and started reading the Factory Service Manuals to get an idea of where to start looking. Looking at how the system worked, it takes most of its signals from the VSS to tell the vacuum solenoids to accelerate or decelerate. I thought that it was using the TPS data, but from what I can tell, it doesn't. Now, something else had been noticeable recently, and that was that the speedometer needle was getting a lot more jumpy and erratic. Of course, the VSS also takes its data from the speedo cable, so to confirm, I plugged in the Brainmaster and checked the VSS readings. When traveling at a constant speed, i.e. 35mph, the VSS reading could fluctuate by as much as 10 mph (it would spike more up than it would down). It would do the same at higher speeds too. Therefore, unless I'm mistaken, the erratic VSS signal is causing the Cruise Control to be unstable as it is trying to match an at times wildly fluctuating speed. It also means that at low TCC lock up speeds, the TCC controller is seeing a sudden change in speed and drops out of lock up. Thus my mpg will be suffering at speeds below 55mph because the TCC doesn't stay enganged constantly as it should. At least, that's my theory. If I'm correct, then I need to get my speedometer cable oiled so that it stops jumping all over the place, which will also stabilise the cruise control and TCC lock up.

Back to trying to set the Idle Air Bleed for the mixture control dwell. As I had mentioned earlier, I had been using the Brainmaster to set the MC Dwell, with common advice being to use an analogue dwell meter. A little bit of hunting on Ebay and I had another new toy to play with:

[Linked Image]

It's a surprisingly large meter, though luckily it's in very good condition and in a nice case. Today I tried it out to make sure it worked, and also to have another go at adjusting the MC Dwell. I connected the meter to the green MC Dwell connector on the carb, set it to 6 cylinder dwell scale, had the engine up to operating temperature and in closed loop while idling in drive at approx. 600rpm. I also had the Brainmaster connected simultaneously showing the MC Dwell reading digitally. As per previous attempts, turning the IAB screw didn't seem to get the reading much above 30 degrees,nor did it seem to cause the reading to change much. In a fit of frustration I turned the screw I think a whole turn, and lo and behold, now I was getting readings well above 30 degrees! I also had the analogue meter needle fluctuating between approx. 26 and 35 degrees. Video below shows the meter in action:

https://youtu.be/ySbESl4iOQI

Is this the sort of behavior expected of the MC Dwell when being read by an analogue meter?

Interestingly, the Brainmaster scanner readings weren't that far off the analogue meter, and in fact matched it quite well. I guess that I am very used to observing digital devices so it wasn't that hard for me to work out the highs/ lows/ average of the digital read out. I certainly agree that the analogue dwell is a lot easier to comprehend needing just a glance at the needle rather than taking note of the numbers.

And here's a picture of the IAB screw showing approx. 7 threads above it. Hopefully not too far off?

[Linked Image]

I took the car out tonight and continued reading the MC dwell via the Brainmaster. It now seemed to be on the high side of 30 degrees, so I tweaked the IAB screw by abouyt 1/4 of a turn, and now it's reading around 30 - 36 degrees at idle in drive. I will tweak it a little more on each drive until the number more settles around 30 average, and I will double check it with the analogue meter once I feel it's getting close.

Hopefully I'm on the right track and will get my '86 running better than she has in years. Oh, and if anyone could confirm that an erratic VSS reading will cause unstable cruise control operation and also affect the TCC lockup that would be very helpful. I can then add oiling/ replacing the speeometer cable to my list.

Onwards and upwards hopefully!


1986 Monte Carlo SS

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#1054825 - 12/14/17 07:31 PM Re: Excessive MPG? [Re: ChasUno]  
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mmc427ss Offline
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The VSS sender is located on the back side of the speedometer. The signal from the sender goes to the Buffer, the buffer will then send a signal to the ECM, and also to the Cruise module. So, yes a bouncing needle will send an erratic signal to both the ECM and Cruise.

Generally when it's time to fix a speedo cable problem it's best to just replace the cable. As far as lubing the cable I have never found a product that would be specific to that. There are graphite, white lithium, bearing grease, oils and several other things people have used but I have never found a "this is what GM used" lube. You need to remove the cable from the back of the speedo, pull it through the firewall into the engine bay to remove the inner cable from it's sheathing to clean, inspect, and lube the cable.
I replaced my cable 15 years ago.

The speedo cable is the one that wraps around under the master cyl in a tight radius. Also has a tight 90 degree bend when it comes across the trans crossmember and turns forward to the frame. Both areas can be causing a problem.
Bob

#1054827 - 12/14/17 08:11 PM Re: Excessive MPG? [Re: ChasUno]  
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Hunter79764 Offline
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Just for the record, I tried white lithium on mine and it was great, for about 10k miles. Now I've gone an additional 10K after it started bouncing and it's as bad as before, possibly worse.


Sometimes you just need a bigger hammer...

'85 MC with budget 5.3L swap, TH350 with stock 2.14 rear end
It ain't much off the line, but it's nice on the highway
#1054842 - 12/15/17 11:13 PM Re: Excessive MPG? [Re: ChasUno]  
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Buick Runner Offline
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Remember, when adjusting the IAB, to check the dwell reading with the aircleaner lid on.


SBC powered 1987 Regal with TES headers, ZZ4 intake, ZZ4 PROM chip, mini starter, THM2004R, 2500 stall converter, 2040 cam, CCC system, and 3.73 posi rear.

2008 ex NPS P71 Crown Victoria, cop motor, cop shocks, cop brakes.

Never argue with an idiot.
They will just drag you down to their level and beat you with experience.
#1054870 - 12/18/17 04:22 AM Re: Excessive MPG? [Re: ChasUno]  
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ChasUno Offline
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Bob, thanks for clarifying the relationship between the speedometer cable, the VSS and the cruise/ ECM. As per above, I'm beginning to suspect that much of my poor MPG is due to the TCC lock up not operating as well as it should due to the fluctuating VSS readings.

From what you said (and Hunter79764), and by the time the speedometer cable has been pulled through the firewall, after getting that far it's more prudent to change the cable than try and grease/ oil it for a temporary fix. At least, depending on how easy it is to unhook it from the transmission and thread it up into the engine compartment.

Any pointers as as to where to get a quality replacement cable? Mike's Montes doesn't appear to sell them at all, and Autozone has a few including "repair kits". Most of the cables I can see appear more kits than fully assembled cables. Here's the link to the Autozone cables:

https://www.autozone.com/drivetrain...mString=search&isIgnoreVehicle=false

Buick Runner, good call on pointing out that the IAB dwell reading should be taken with the air cleaner lid on. Yes, that's what I have been doing, tweaking the IAB screw and then replacing the lid. Once I am getting close to a 30 degrees average reading, I then drive the car around for a while and use the Brainmaster scanner to read the MC Dwell to see how it settles. If it goes too far one way or the other, then I give the IAB a small tweak to richen/ weaken the IAB and then continue monitoring the MC Dwell over a period of time. Once it seems close, then I will double check with the analogue meter.

I've done a few more checks of the system, this weekend, this time checking the heat riser valve in the exhaust and the Thermac valve in the air cleaner. The heat riser appears fine and is not seized as it can be moved easily by hand and the spring pushes it back when moved. With the engine off and cold, I checked the position of the actuating arm, started the engine and noticed that the arm retracts and there is vacuum pressure from the vacuum pipe. I then drove the car and got it up to operating temperature, checked the position of the actuating arm with the warm engine idling, and it had retracted back to the original position. There was also now no vacuum present at the heat riser vacuum line. Thus, the heat riser appears to be operating correctly and is not stuck in the closed position.

On to the Thermac valve. I had noticed that that the air cleaner diverter flap never moved, whether the engine was hot or cold. I was able to confirm that the flap was functioning simply by applying vacuum to the flap motor, and it closed and held vacuum fine. I also confirmed that vacuum was present in the vacuum line from the carburetor vacuum line to the Thermac. Almost certain then that the Thermac had failed, so I looked online to see where I could find a replacement. In doing so, I had a bit of a shock. How feckin' much?!!!!!!!!! They seem to be running around $75 or so, for what is nothing more than a few bits of pressed steel enclosed in a moulded plastic housing. I was expecting them to cost a similar amount to a thermostat ($15 or so), and really didn't think they'd be as expensive as they are. I tried Ebay, Autozone and general web searching with much the same results. I tried changing my search query on Ebay and found one that looked very, very similar and this time it was only $10. It may not be the correct part or correct heat rating, but heck, if it works near enough for only $10 I figured it was worth it. As such, I pulled the trigger on it as it was there was only one for sale. It remains to be seen if it will fit and work correctly, though I might be lucky. Here's the link to the Ebay auction with the item I bought:

https://www.ebay.com/itm/Vintage-Carter-TS18-Air-Cleaner-Temperature-Temp-Sensor/182933541334?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

And here's how an AC version listed as suitable for a 305 V8 looks:

[Linked Image]

Pretty much exactly the same design and plastic housing, though how much the temperature operation varies between specific applications I don't know. I also figured that as I live down here in Florida it's not that essential for most of the year anyway seeing as it's warm/ hot most of the time. With the exception of maybe two or three weeks of the year, even the heater is hardly ever needed. Still, I will see if the Carter thermac fits and works.

I was curious as to why my Thermac was not working I couldn't see anything obvious just by looking at it. I could see that it had a pin that raised and lowered via a thermo spring, though I couldn't see how it opened/ closed a vacuum port. As the Thermac was simply two sections of steel pressed together, I took it apart in the name of research. I took off the outer plastic case, then prised the two housings apart. This is how a disassembled Thermac looks:

[Linked Image]

And when I first took the two halves apart, the reason it didn't work became obvious:

[Linked Image]

That black plastic plug on the right should be attached to the end of the pin that is raised lowered by the thermo spring. As it had become detached it could not seal the hole in the upper half, explaining why the air cleaner flap never operated.

This following picture shows the upper housing with the spring operated pin, and the plastic plug that should be attached to the end of the pin from the underside of the base:

[Linked Image]

Out of interest, I managed to reassemble the Thermac valve and get the plastic plug reattached to the pin. It still didn't work until I bent the spring to create more tension. There was an adjusting screw to do this, but I had already maxed it out. With the bent spring giving more tension, the valve now worked and operated the air cleaner flap! But the tension was now wrong as it wouldn't release the flap once the engine was warm. Ho hum!

Once the Carter thermac switch arrives I will try that and maybe I'll get lucky. If not, I may just delete the Thermac valve entirely because as I mentioned above, it's likely not really necessary most of the time down here in FL.

Last edited by ChasUno; 12/18/17 04:28 AM.

1986 Monte Carlo SS

[Linked Image]
#1054871 - 12/18/17 06:47 AM Re: Excessive MPG? [Re: ChasUno]  
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mmc427ss Offline
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As you said the thermac isn't needed in Florida. Even with the air cleaner I use the thermac is installed but I don't use it, the vac supply line just isn't plugged in. Many years ago I replaced one and it was like 20 bucks, today for 75 bucks it's just not needed at that price, even up here in the north. Yes it's nice to have hot air pulled off the exhaust manifold to heat the cold air when the carb and intake are very cold. The thermac has been a part of the stock air cleaner for 40+years, my 72 Chevelle had that system even back then.

There are different colors of thermacs, blue , brown and I think a whitish one, i would assume they are different temp setups.

The heat riser in the right side exhaust is another one of those parts that go bad over time. They may stick closed, open, partially closed. Again in Florida you can get by without having it functional, as long as it's stuck open. When working properly it redirects hot exhaust from the the right side, from I believe #6 exhaust port in the head, into and across the intake manifold in a "crossover" passage below the plenum, into the #5 s exhaust port in the head and exiting the left exhaust manifold. A thermal controlled vac switch located in the coolant passage in the front of the intake controls the valve. The problem with the system is when the head or intake passage for the crossover heat become "coked", clogged, the system doesn't work. Or if the valve becomes inoperative, or thermal valve fails. Again up north it would be a good system to have, down south not so much. Most high performance heads, intakes don't have provisions for crossover heat. Most intake gaskets sets will have steel plates to block the passages, this to keep the intake manifold colder.
Bob

#1057013 - 04/24/18 03:32 AM Re: Excessive MPG? [Re: ChasUno]  
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ChasUno Offline
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Hi all,

Been a bit quiet from my end for a number of reasons, mainly because my other half had an accident in February, fell awkwardly and badly injured their Achilles tendon and calf muscle. They're having to use a walker until it heals, and as it's their right foot that got injured, it's also affected their ability to drive. That means I've been having to drive them everywhere until the physio gets their foot/ ankle working again. Then we had a bump with our Lexus when a woman (on her damn phone and not concentrating on the road properly...) swung wide on a left hand turn, came into our lane and damaged the door and fender. That required a whole load of chasing up and inconvenience. As a result, I've not had much chance to get working much on the Monte for a quite a while, though I've started cracking on with it again over the past couple of weeks.

I've also done another fill up (last February), and there's a little more improvement in MPG. It's now up to 13.2 compared with the previous 11.8 mpg. This is mostly round town driving and local highway (50mph), no mashing the accelerator or high speed interstate running. I've also finally got round to changing the transmission sump gasket and put in new fluid to replace that which came out. Having a nightmare trying to get the sump pan to not leak, despite following directions and torquing it gradually in a criss cross pattern, and initially tightening the pan bolts to 8 - 10 lbs/ ft. It was leaking before, and I put that down to the sorry state of the original gasket that literally crumbled to bits when I took the sump pan off. I also have a leaking master cylinder and rear pinion seal, and I still need to change the valve stem oil seals. Never a dull moment!

Despite the mpg not being as good as it should be (15 mpg around town according to the brochure), the engine seems to run very well and ticks over nice and reliably at around 600 rpm. It revs smoothly and has a nice bit of a power kick when you bring in the secondary chokes, and according to the Brainmaster Scanner most of the sensors and settings are all within their correct ranges. Just wish it would get a little closer to 15 mpg, especially with gas prices on the rise again!

Here's the latest Fuelly report:

[Linked Image]

Last edited by ChasUno; 04/24/18 03:34 AM.

1986 Monte Carlo SS

[Linked Image]
#1057014 - 04/24/18 03:56 AM Re: Excessive MPG? [Re: ChasUno]  
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86ttop Offline
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86ttop  Offline
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around town use is having negative effects on your gas mileage


Leo Paugh
It's not an attitude, it's just the way I am.
POW*MIA
You are not forgotten
If things improve with age, I must be approaching magnificent. thumbs
#1057020 - 04/24/18 01:27 PM Re: Excessive MPG? [Re: ChasUno]  
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A point to remember when making/tuning the CCC system is to disconnect the battery for a couple minutes to clear any stored codes in the ECM after your are finished, and to start fresh with the BLM.
A very nice tool for anyone working on OBD 1 GM vehicles is a FREE program called "WINALDL", this program can run on a laptop computer (hooked up through the ALDL) and show you "REAL TIME"
data of all sensors, switches, flag data, codes, as you drive, It was a life saver for me when I was tuning my Monte.

#1057024 - 04/24/18 03:18 PM Re: Excessive MPG? [Re: ChasUno]  
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Witness86SS Online content
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According to bitflipper the monte ECM doesn't store any data between starts. It's too small and primitive.

I agree on the around town aspect of the mileage. The monte's claimed mileage is from a time of a lot less rules on how that mileage was calculated. Probably a professional driving it like a grandma for almost unachievable results.


Quote

Concerns over EPA estimates
For many years critics had claimed that EPA estimated fuel economy figures had been misleading. The primary arguments of the EPA detractors were focused on the lack of real world testing, and the very limited scale (i.e., city or highway).

Partly as a response to these criticisms, the EPA changed their fuel economy rating system in 2008 in an attempt to more adequately address these concerns. Instead of testing simply in two presumed modes, the testing now covers:[33]

Faster speeds and acceleration
Air conditioner use
Colder outside temperatures
While the new EPA standards may represent an improvement, real world user data may still be the best way to gather and collect accurate fuel economy information. As such the EPA has also set up a http://www.fueleconomy.gov/mpg/MPG.do?action=browseList website where drivers can enter and track their own real-world fuel economy numbers.

There are also a number of websites that attempt to track and report individual user fuel economy data through real-life driving. Sites or publications such as Consumer Reports, Edmunds.com, Consumer Guide and TrueDelta.com offer this service and claim more accurate numbers than those listed by the EPA


Justin
1986 Black SS
350 L05 - Hooker Longtubes - FlowMaster True Dual 2.5" - Electric Cutouts - Electric Fans - Transcooler
#1057025 - 04/24/18 03:35 PM Re: Excessive MPG? [Re: ChasUno]  
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Hunter79764 Offline
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Also note that gasoline in 1985 was actually gasoline, not E10 like it is now. That's about a 5% hit thermodynamically, sometimes more, sometimes less in the real world.


Sometimes you just need a bigger hammer...

'85 MC with budget 5.3L swap, TH350 with stock 2.14 rear end
It ain't much off the line, but it's nice on the highway
#1057027 - 04/24/18 04:46 PM Re: Excessive MPG? [Re: ChasUno]  
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Buick Runner Offline
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Dharma station 1 the Hydra
Also sometimes what is labeled as E10 gas can really be E15 or even E20. There is some pretty bad quality control with modern gas.


SBC powered 1987 Regal with TES headers, ZZ4 intake, ZZ4 PROM chip, mini starter, THM2004R, 2500 stall converter, 2040 cam, CCC system, and 3.73 posi rear.

2008 ex NPS P71 Crown Victoria, cop motor, cop shocks, cop brakes.

Never argue with an idiot.
They will just drag you down to their level and beat you with experience.
#1057041 - 04/26/18 04:30 AM Re: Excessive MPG? [Re: Buick Runner]  
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ChasUno Offline
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Bradenton, FL
Originally Posted by 86ttop
around town use is having negative effects on your gas mileage


That's very true, Leo. However, when I asked on the Classic G Body Garage Facebook page, people where claiming that they were getting close to 250 miles to a tank of fuel. I was luck to get 180 at times, with the best so far being close to 200 miles. Though I am doing a fair bit of city driving, it's fairly gentle and I'm not sitting in crawling traffic for any extended periods. Maybe 200 miles to a tank is normal for most?


Originally Posted by supernova455
A point to remember when making/tuning the CCC system is to disconnect the battery for a couple minutes to clear any stored codes in the ECM after your are finished, and to start fresh with the BLM.
A very nice tool for anyone working on OBD 1 GM vehicles is a FREE program called "WINALDL", this program can run on a laptop computer (hooked up through the ALDL) and show you "REAL TIME"
data of all sensors, switches, flag data, codes, as you drive, It was a life saver for me when I was tuning my Monte.



Thanks for that, and yes, I have disconnected the battery previously to clear stored SES codes. So far, at least since I sorted out a lot of issues and sensors, no SES codes at all. The SES dashboard light works, and I can also read the codes via the BrainMaster scanner (none stored).

I looked up WINADL.

http://winaldl.joby.se/

Seems like a nice little program, BUT, I'm not sure how compatible it would be with modern computers. According to the website, it requires: "A PC with a serial rs232 port running a Win32 enviroment. ( Windows 95/ 98/ ME or Windows NT / 2000 / XP )". All my computers are now running 64 bit Windows 10, and my laptop has no RS232 port! It seems a real shame that the program doesn't seem to have been updated to be compatible with modern computers. Additionally, as mentioned above, I have a BrainMaster II scanner that can read all the sensors and ECM information mostly in real time. Granted, only one parameter at a time but it's been incredibly helpful with my fine tuning. It's a shame some computer wizard out there hasn't programmed an updated WINADL for modern computers, but I guess it's a very limited market.

Originally Posted by Witness86SS
According to bitflipper the monte ECM doesn't store any data between starts. It's too small and primitive.

I agree on the around town aspect of the mileage. The monte's claimed mileage is from a time of a lot less rules on how that mileage was calculated. Probably a professional driving it like a grandma for almost unachievable results.


The ECM does store fault codes between starts. Also, I was informed by someone that the ECM has to "learn" when reset, and until a few miles have been traveled it won't be at its optimum performance. I didn't think an ECM as old at the GM OBD 1 system could do this, though I have no way of confirming whether it can or not.

Originally Posted by Hunter79764
Also note that gasoline in 1985 was actually gasoline, not E10 like it is now. That's about a 5% hit thermodynamically, sometimes more, sometimes less in the real world.


Originally Posted by Buick Runner
Also sometimes what is labeled as E10 gas can really be E15 or even E20. There is some pretty bad quality control with modern gas.


And that can certainly be a factor also. Fuel is not the same as it was back in the 80's, and absolutely, the "EPA fuel consumption figures" back then were somewhat measured in a perfect world artificial environment. Hence why I asked in the FB group what kind of mileage people were getting from a full tank of gas on average. Going by a number of responses, mine was right at the low end, with most getting considerably better than 180 miles to a full tank. It seemed that 230 - 250 seemed to be what others were getting.

I will continue monitoring my fuel ups and see how they compare. If they are consistently averaging around 12 - 13 mpg with my regular type of driving, maybe that's just what I'm going to get with this car. Time will tell.


1986 Monte Carlo SS

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#1057049 - 04/27/18 02:11 AM Re: Excessive MPG? [Re: ChasUno]  
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86ttop Offline
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86ttop  Offline
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the 3.73 diff ratio at low speeds has a major effect on around town(city) fuel mileage!


Leo Paugh
It's not an attitude, it's just the way I am.
POW*MIA
You are not forgotten
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#1057079 - 04/29/18 08:11 PM Re: Excessive MPG? [Re: ChasUno]  
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Perhaps the O2 sensor has become slow? When O2 sensors age, they become slower which can eat up gas, however, they will still give correct readings and not throw codes despite going bad.

For the TPS, there are a few things to check. Sometimes the little plunger rod in the airhorn can be bent, or it's seal can stick. Sean Murphy in one of his articles says to lightly grease the sensor in its bore, and to lightly stretch the return spring that fits under the TPS in its bore.


SBC powered 1987 Regal with TES headers, ZZ4 intake, ZZ4 PROM chip, mini starter, THM2004R, 2500 stall converter, 2040 cam, CCC system, and 3.73 posi rear.

2008 ex NPS P71 Crown Victoria, cop motor, cop shocks, cop brakes.

Never argue with an idiot.
They will just drag you down to their level and beat you with experience.
#1057130 - 05/02/18 03:09 AM Re: Excessive MPG? [Re: Buick Runner]  
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Thanks for the suggestions Buick Runner.

I fitted a new O2 sensor last December. I have done relatively few miles since, so it's in virtually new condition. It doesn't flag up any faults via the ECM, so unless it's running slow as you said above, I can assume for now that it is functioning correctly.

Good call on the TPS. The plunger appears to move freely and shows no sign of sticking. I didn't use any grease when I fitted a new TPS, and didn't lightly stretch the spring. I could try those tricks at some point once I finish some other jobs on the car.

Who is Sean Murphy and where can I find his articles?


1986 Monte Carlo SS

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#1057131 - 05/02/18 03:38 AM Re: Excessive MPG? [Re: ChasUno]  
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Buick Runner Offline
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Sean Murphy is one of the few reputable Qjet rebuilders out there besides Cliff Ruggles. Most carb rebuilders are very poor anymore, especially with Qjets, the worst being remanufactured Qjets. A quick search on the net should pull up some articles.


SBC powered 1987 Regal with TES headers, ZZ4 intake, ZZ4 PROM chip, mini starter, THM2004R, 2500 stall converter, 2040 cam, CCC system, and 3.73 posi rear.

2008 ex NPS P71 Crown Victoria, cop motor, cop shocks, cop brakes.

Never argue with an idiot.
They will just drag you down to their level and beat you with experience.
#1057298 - 05/15/18 02:59 AM Re: Excessive MPG? [Re: Buick Runner]  
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ChasUno Offline
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Originally Posted by Buick Runner

For the TPS, there are a few things to check. Sometimes the little plunger rod in the airhorn can be bent, or it's seal can stick. Sean Murphy in one of his articles says to lightly grease the sensor in its bore, and to lightly stretch the return spring that fits under the TPS in its bore.


All good advice, thank you Buick Runner!

Originally Posted by Buick Runner
Sean Murphy is one of the few reputable Qjet rebuilders out there besides Cliff Ruggles. Most carb rebuilders are very poor anymore, especially with Qjets, the worst being remanufactured Qjets. A quick search on the net should pull up some articles.


I did a search and indeed, I found some articles about Sean Murphy regarding QJets.

Also, your comment in the quote above about the TPS return spring. I found some discussions where it was this spring that caused a number of issues for some people's QJet CCC operation, and it also got me thinking. One thing I noted was how much the TPS reading would go up and down depending on engine temperature. After running, the reading would go higher (above 0.8v), and with the engine stopped and cooling down, it would drop to as low as 0.3v. I was originally suspecting that the throttle shafts were worn causing unstable positioning at idle, though these seem fairly consistent depending on the engine temp. I thought also that maybe the new TPS sensor I fitted was faulty and the heat was affecting its operation/ electrical conductivity. Then I read that it uses a carbon film as its 'potentiometer', and this should be far less susceptible to heat. Then in one article, as I mentioned earlier, one owner said a lot of his erratic TPS behavior was eventually traced to a weak TPS return spring.

Now, the TPS return spring is a simple piece of coiled wire, as per most springs. I don't know for sure, but it's highly likely that the spring in my QJet is the original item from new (the QJet appears to be original, along with much of the rest of the car). That means the TPS spring is 32 years old, and any spring that old will eventually have weakened with use, and additionally, being made of metal it's tension can vary depending on temperature. It's just a theory, however, I am wondering if just maybe my TPS return spring has become weak with age and is therefore changing tension with heat, causing the TPS sensor to vary its position. This is turn might explain the TPS readings at closed throttle being higher when warm and lower when cold. Just maybe!

The same owner (I can't remember exactly where I saw the discussion thread) I think used double return springs, which apparently solved the TPS issues. I don't have access to a spare spring to double them up, but I can always try stretching the spring a bit to see if that helps. The Quadrajet Parts website has used springs available, though with shipping they were at nearly $12, which seems a little pricey for a coiled bit of wire!

For the time being, I will plan on taking the top of the carb, removing the TPS and spring and then stretching the spring somewhat to see if that has any effect. If it does, it might solve the issue of varying TPS voltages. If it goes back to being weak again, then maybe I will go the double spring route.

Out of curiosity, does anyone know why the QJet TPS uses a return spring instead of having the TPS fixed solidly in place? Is it for damping purposes, or purely so that the plunger doesn't bottom out and damage the sensor? On more modern TPS units used on TBi style fueling, they seem to be firmly attached with no sign of any spring damping.


1986 Monte Carlo SS

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#1057301 - 05/15/18 05:09 AM Re: Excessive MPG? [Re: ChasUno]  
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Buick Runner Offline
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That is an interesting idea. The electronics in E4MEs ars pretty much a retrofitted design. One downside to Qjets is their poor throttle shaft bearing design which is riding directly in unbushed bores that wear out. Rather than improve this design, I suspose GM desided it was cheaper to use a plunger style sensor in contact with the accel pump lever rather than use a throttle shaft mounted TPS. The TBI units use replacable Teflon throttle shaft bushings besides being a dedicated design rather than a retrofit design.


SBC powered 1987 Regal with TES headers, ZZ4 intake, ZZ4 PROM chip, mini starter, THM2004R, 2500 stall converter, 2040 cam, CCC system, and 3.73 posi rear.

2008 ex NPS P71 Crown Victoria, cop motor, cop shocks, cop brakes.

Never argue with an idiot.
They will just drag you down to their level and beat you with experience.
#1057305 - 05/16/18 01:29 AM Re: Excessive MPG? [Re: ChasUno]  
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86ttop Offline
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86ttop  Offline
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Posts: 11,305
Brooksville, Fl
I send all my E4ME carbs to www.customrebuiltcarbs.com and pretty much install and go. Click on my link and give them a call!!


Leo Paugh
It's not an attitude, it's just the way I am.
POW*MIA
You are not forgotten
If things improve with age, I must be approaching magnificent. thumbs
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