MonteCarloSS.com
MonteCarloSS.com

CELEBRATING 20 YEARS!

Previous Thread
Next Thread
Print Thread
#1064569 - 12/25/19 07:38 AM Fuel tank and sending unit  
Joined: Nov 2008
Posts: 602
jmireles Offline
10+ Year
jmireles  Offline
10+ Year
Member

Joined: Nov 2008
Posts: 602
El Paso, Tx
When I LS swapped my Monte, I kept the original tank and sending unit. I bought a retro kit from Tanks Inc. that enabled me to use fuel injection. The conversation did not go as smooth as I'd hoped for. So, I'm planning on buying a new tank for a V6, which we all know has the baffling first fuel injection. I also intend to purchase the stock V6 fuel pump hanger and sending unit. I'll just transfer the Walbro 255 pump to the new unit.

Now for my question, which is wiring...
The stock carbureted V8 sending unit has a spade connector for the fuel gauge and the ground wire. The fuel injected V6 hanger looks different (at least from the pictures I saw on Rock Auto). It appears as there is no provision for the stock fuel gauge wire to connect to. How do I do this?

Thanks


-'87 Monte SS LS 2/4L65e Quick Perf. 9" w/disk brakes
-'89 Iroc Z28 Stock 5.7 Edelb. TES headers, Borla Exhaust90K
-'77 Trans Am 468(Stroked) Doug's Headers Flowmaster catback
B & M shift Kit 400 Turbo trans. Edel brock Performer
RPM Intake Sean Murphy built Rochester Carb. Restored
in '08. 3K
#1064578 - 12/26/19 05:50 AM Re: Fuel tank and sending unit [Re: jmireles]  
Joined: Jan 2000
Posts: 4,535
mmc427ss Online content
20+ Year
mmc427ss  Online Content
20+ Year
Member

Joined: Jan 2000
Posts: 4,535
Pottstown, Pa
Assuming the tank you are looking at is this? Good tank, have the a GM306C installed in my car. Not using it for the FI but for it's sump for a custom pickup.
https://ecat.spectrapremium.com/products/GM306C

Can't speak directly to what others have done for a FI pickup/sender for that tank. Specte has this one for the 87 FI 4.3 Monte. I think the pics are a little inaccurate and don't show the wires correctly. Whether the Welpro pump is a direct bolt in I don't know.
https://ecat.spectrapremium.com/products/SP172A1H

One thing I would do if I would ever buy a new tank for the SS is install a revent to make fill up much easier. A 1/2 tube from the top of the tank to the right or left of the fill tube, running up to an inch below the fuel cap. This would allow the tank to burp/purge the air in the tank when filling. Now having this 86 for 25 years and hundreds of fill up way to many times has gas came back up the filler. Venting would fix that and wouldn't effect emissions.
Bob

#1064582 - 12/26/19 05:24 PM Re: Fuel tank and sending unit [Re: jmireles]  
Joined: Nov 2008
Posts: 602
jmireles Offline
10+ Year
jmireles  Offline
10+ Year
Member

Joined: Nov 2008
Posts: 602
El Paso, Tx
Those look like the ones I saw on Rock Auto. I guess I'll have to order the unit and see how I can modify the wiring to work with my setup.


-'87 Monte SS LS 2/4L65e Quick Perf. 9" w/disk brakes
-'89 Iroc Z28 Stock 5.7 Edelb. TES headers, Borla Exhaust90K
-'77 Trans Am 468(Stroked) Doug's Headers Flowmaster catback
B & M shift Kit 400 Turbo trans. Edel brock Performer
RPM Intake Sean Murphy built Rochester Carb. Restored
in '08. 3K
#1064586 - 12/27/19 03:15 AM Re: Fuel tank and sending unit [Re: jmireles]  
Joined: Jan 2000
Posts: 4,535
mmc427ss Online content
20+ Year
mmc427ss  Online Content
20+ Year
Member

Joined: Jan 2000
Posts: 4,535
Pottstown, Pa
From the 87 Helms Electrical Supp for a FI V6 pump/sender wires:
Purple-gauge
Black-gauge ground
Tan- pump +
Black/White- pump ground

Making sure the pump has sufficient power all the time is important. The GN boys have wire upgrade kits available. Here's some DIY info on the subject.
https://buickturboregal.com/diy-fuel-pump-hotwire-kit-buick-grand-national/

Bob

#1064589 - 12/27/19 02:43 PM Re: Fuel tank and sending unit [Re: jmireles]  
Joined: Nov 2008
Posts: 602
jmireles Offline
10+ Year
jmireles  Offline
10+ Year
Member

Joined: Nov 2008
Posts: 602
El Paso, Tx
Thank you. I bought a Racetronix fuel pump harness that the Buick GN guys use. I had to modify it slightly to make it work with the Tanks Inc. set up I have now.


-'87 Monte SS LS 2/4L65e Quick Perf. 9" w/disk brakes
-'89 Iroc Z28 Stock 5.7 Edelb. TES headers, Borla Exhaust90K
-'77 Trans Am 468(Stroked) Doug's Headers Flowmaster catback
B & M shift Kit 400 Turbo trans. Edel brock Performer
RPM Intake Sean Murphy built Rochester Carb. Restored
in '08. 3K
#1064678 - 01/06/20 08:50 AM Re: Fuel tank and sending unit [Re: jmireles]  
Joined: Nov 2008
Posts: 602
jmireles Offline
10+ Year
jmireles  Offline
10+ Year
Member

Joined: Nov 2008
Posts: 602
El Paso, Tx
I finally finished installing the new tank today. I had to modify the hanger a bit so here's what I did:
1) cut off the fuel pump connector to wire in the connector that came with the Tanks Inc. set up. I had to do this in order reuse the Walbro 255 pump.
2) I had to separate the pump ground wire and the sending unit ground wire.
3) cut off the spade connector from the old tank sending unit power wire and wired it to the new unit.
4) cut off the tips of the feed line and return line so I could install A/N compression fittings.
5) I had to bend the lip of the tank to clear the frame and tank straps.

I made sure there were no leaks. I'll have to check the vent line since it is not relieving pressure adequately. I hear a hiss but not from the gas cap. When I tried fueling the car, it spat fuel back! I reduced the amount flowing in and slowly took it to half tank. I'll need to research the emissions system of the Monte to see where I might have gone wrong.


-'87 Monte SS LS 2/4L65e Quick Perf. 9" w/disk brakes
-'89 Iroc Z28 Stock 5.7 Edelb. TES headers, Borla Exhaust90K
-'77 Trans Am 468(Stroked) Doug's Headers Flowmaster catback
B & M shift Kit 400 Turbo trans. Edel brock Performer
RPM Intake Sean Murphy built Rochester Carb. Restored
in '08. 3K
#1064744 - 01/10/20 03:27 PM Re: Fuel tank and sending unit [Re: jmireles]  
Joined: Mar 2000
Posts: 5,522
upflying Offline
15+ Year
upflying  Offline
15+ Year
Member

Joined: Mar 2000
Posts: 5,522
Reno, NV
I have a Buick GN tank and a Walbro 255gph pump and 58psi regulator. I left the OEM tank vent to the charcoal cannister open during my install. My tank occasionally burps back at me if I fill at a station that is less than level. I try to put my front wheels off the station pad to drop the front a bit when fueling. No more burps.
During the tank install, I cut a "door" on the floor of my trunk to service the pump and check for leaks without having to drop the tank.


86 MCSS Notchback coupe, LS3, 4L65E, QP 9", Eaton Truetrac, 4 wheel disc, column shift, Dakota Digital, silver with maroon bench interior

[Linked Image]

Random Images
500/thumbs/HPIM3730.JPG
by miker82
902/thumbs/monte114.jpg
by SKIDMARK
500/thumbs/100_16041.jpg
by myfirstmontess
500/thumbs/04.JPG
by Ole Blue
892/thumbs/S3010011.JPG
by Intmdatr3
Help MonteCarloSS.com


Recent Contributors
finallySS
Authorized Vendors
Tell them you saw it
on MonteCarloSS.com!


CustomMonteSSParts.com
Dixie Monte Carlo Depot
GSI Interiors
HRpartsNstuff
Mikes Montes
Savitske Classic & Custom
Powered by UBB.threads™ PHP Forum Software 7.6.0