85f-bird

Hey all,

So I finally got my column wiring figured out in my 85 Firebird thanks to a member who helped me in the electronics board. My car hasn't run for about 5 years. I backed it off the trailer and into the garage, then started taking parts off...one thing led to another and I hadn't gotten it back together (or running) again. Well, now that the column wiring is working right, I've had the chance to crank the car over. Checked for spark and it looks good with a tester on a lead/plug. But I didn't hear my fuel pump prime like it used to (or like my 92 camaro does).

I followed instructions from the board and applied 12V to the ALDL terminal G. When I do this, you can hear a small "click" from the rear of the car, but the pump doesn't turn on. Considering I can hear the pump "attempt" to do something, can I assume that the relay is functioning properly?

Is there something else I should be looking at before I start dropping the tank to replace the fuel pump?

eseibel67

Your pump could very well be fried, but first check to make sure the pump is getting enough power before you go through the hassle of dropping the tank. There is a connector near the front of the tank, make sure when that the wire is supplying full voltage. Ii I recall, there are 3 wires, grey, purple and black. Check voltage between the grey and black during prime.

85f-bird

Thanks! Obviously I should be able to reach it w/o dropping the fuel tank, correct? I know where the wires go behind the back seat (under the carpet) but didn't know if you could reach those from under the car, or if they came out on top of the tank.

Also can't believe the fuel pump went bad after sitting for this long. The car hadn't been regularly driven since 2009, but the pump had been replaced less than 50,000 miles ago. Had imagined the pump itself would have been ok. Would sitting in bad gas cause it to go out?

Piston454

There is also an oil pressure switch that needs to be sending a signal to kick on the fuel pump (or even to prime the system before you turn the key all the way). My connections were dirty on my car and one day it wouldn't fire because it wasn't sensing the oil pressure switch. Just another idea for you to check.

i88aGT

I recently read thru most of the threads on fuel pump / no-start posted here. I would do that if I were you before settling on a fuel pump problem, because it helped me diagnose a faulty $20 maf relay instead.
Check the power as suggested, and the fuel line pressure if u can.
I read here and in gm manual that the oil pressure sensor is the backup. but manual says it and circuit wiring should be checked before dropping tank.
Use data to diagnose and if u gotta swap read the part recommendations.
Good luck!