Overview first.........(yes I've searched, not a nOOb)

1986 Trans Am 305 TPI, 113,000 miles.

Car died 3-4 months ago, finally got around to working on it.

No fuel pressure and no hum from the pump.

Swapped around the relays on the firewall since I knew they were failure prone as is the pump also. Had 12+ volts.

No good, so I ordered a 190 LPH from APE, great service as always.

Hooked up the new pump before installing it into the tank, no go.

Checked voltage......6.2 volts......thinking I dropped the tank for no reason I used my cordless drill battery pack (13.2v) to test both pumps.

New walbro torqued right up, the stocker did nothing. I dropped it while checking the connections I made. Tried again. It started slowly then after 10 seconds it finally. reach a decent speed. So it was weak and was locked up with debris. I did notice there was no "filter" on the end of the old pump. I even looked inside the tank to be sure it didn't fall off.

The factory fuel pump was replaced at 56,000 miles by GM. The first owner kept excellent service records.

Now my question (thanks for reading.......)

Where would be the "most likely" place in the wiring/relays to be causing the low voltage? Any known problematic connections???

Thanks for the time. I've only drove the TA 1.4 miles since December 2002, and was towed home the same 1.4 miles when it died!

 

Since putting the new pump in, have you started the car and run it any? As far as low voltage, you might check the three wires that run under the back seat and along the frame by the drivers seat to the firewall. Under the drivers seat is where the fuel pump wire is grounded to the frame.

 

I checked the voltage at the rear connector, yet to put the tank back in.

I did more searching (your name up quite a bit) found a few thing to check.

I had a picture saved that someone posted, showed the 3 firewall relays and their purpose.

Also when the car sits, 2 weeks or more, it drains the battery. I did get a new battery, leave it unhooked till this quirk is fixed.

EDIT: If was to apply 12v to the ALDL "G" then I should see the same 12v at the tank connector, correct?


PS I can tackle my 13 second Honda, but this is driving me nuts!!!!!

Mista Bone
"D" Honda tranny guru.

 

On your edit, that is correct. Also a suggestion while you have the tank down and if you haven't already thought about doing it. I would disconnect all the fuel lines in the engine compartment, spray the lines full of carb cleaner and let it sit for a little while (about 15 minutes or so) and then blow the lines out with compressed air. I would also replace the fuel filter since you said the other pump had no sock on it and was full of garbage. Aren't these cars so much fun?

 

Fuel filter was replaced last spring, has a whole 3 miles on it.

I'll hit the lines, good thinking.

My luck by the time I get it running again, gas will be $2 a gallon.

Thanks again.

 

$2.00 a gallon, a report I saw on the internet today is quoting more like $3.00 a gallon. I would still replace that filter and don't forget to replace all the o'rings in the connections.