1987--GTA-

I suspect my fuel pump is going out on the 87 GTA 355 TPI - as after sitting it cranks excessively before it will start, if i turn the key on and let it sit awhile, it will start,, i did not have a pressure gauge but am picking one up tonight--
anyone have a procedure to replace the pump?
tell me the rear end really does not have to be dropped out?
any suggestions for a new pump? just the O'reilly or NAPA ok?

vetteoz

iTrader: (13)

Very common problem with age
Other things to consider 1st with extended crank start; most of which require a gauge to check

Fuel pump may not be running to prime the rail when key 1st turned on ( bad relay / wiring )
Faulty check valve may allow the prime pressure to bleed off before cranking
Faulty reg may allow prime pressure to bleed off to bleed off before cranking.
Lots to check before dropping the tank

Also if the engine runs fine after starting highly unlikely the pump is at fault

vetteoz

iTrader: (13)

Need to understand how things are supposed to work.

When you turn the key on ,the pump relay runs the pump for 2 sec to build pressure ( prime ) in the fuel rails .
This pressure is supposed to hold.
Then when you start cranking , that retained pressure is supposed to supply the injectors which results is a "instant" fire up
When cranking as soon as oil pressure is over 4 psi , a pressure switch then runs the pump in parallel with the relay .
This serves as a backup pump supply should the relay fail ;giving engine start with extended cranking ; which is what you are describing .

If you loose the prime pressure or are waiting for the OP switch to run the pump then you will have long cranking until fuel pressure is available again

1987--GTA-

isn;t the check valve on this car in the tank with the pump?
also i was told there was no relay like this on this year car, i have a 1992 chev 1500 pick up where the relay was replaced due to long cranking which solved the problem, but again i was told the 1987 system was diffrent from this

1987--GTA-

i put a fuel pressure gauge on the GTA:

1. turned key went up to 30 psi right away

2. would not start though, after about 1/2 hr had dropped to about 25

3. let sit about 20 min with key on, started right up but stalled !! (never did that before) got running but ran rough, gauge was now at 45-50 psi while running, sort of was missing and gauge would drop off a few lbs while it did that

4. just recently installed one of those air foil pieces- could i have done something wrong with that to cause the miss?

mcrandrz

Pull the vacuum off the fuel pressure regulator when you start it. any spike in pressure? And any fuel coming out of the fpr its self


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tomsaddy

iTrader: (4)

Are you sure the MAF sensor was reinstalled correctly after the airfoil was installed? A disconnected or backwards MAF sensor will cause it to run pretty bad, although I'm not sure if it would cause your starting problem.

1987--GTA-

i don;t think we disconnected the MAF when we did the conversion, just took off the bellows, but i will check, i had the hard starting for a couple years now, the the rough running is new and the stall, since we did the air foil, i am going to replace the gasket under the TPI embossed plate to be sure the gasket didn;t get in there funny or cracked.