first a little backround i have a 89 gta with a rebuilt tpi 350 that i just fired up a week ago i can get it to run but only while i hold the gas and i have checked everything else and i know its fuel
ive been reading posts tryng to figure this out

1st problem-
recently when i turn the key the pump will not prime i checked all the fuses in the block good fuse by the battery and a new fuel pump relay all the wires are connected no cut wires. the connector for the relay is greasy and dirty but would that be my problem? also i do not have the oil sensor hooked up yet and will do that tomorrow could that be the or a problem? i know its only a back up (so ive heard) any ideas?

2nd problem-
since the pump will not prime i have bypassed they relay and i can get it to work i can get fuel press when the pump is on but i drops immediately to 0 when i stop the pump I have brand new injectors and a new adjustable fuel reg and new fuel filter with half a tank of fresh gas. So i hope its not the injectors or fuel press reg could the o ring seal cause them to leak between injector and manifold? i will try the trick of squeezing off fuel lines to see if injectors or fuel press reg leaks or if the pump check valve is bad. If the check valve is bad isthere any other way of fixing it besides dropping the tank? also can i take the fuel rail out of the manifold with the injecotr still hooked up and test them?(i know it will shoot gas everywhere if theres a leak)


https://www.thirdgen.org/forums/tpi/...way-check.html
thats the post i read on checking injecotrs and check valve

any suggestions tips or advice will help im only 17 and dont have as much experience as you other guys

thanks in advance
brendon

 

You must have an oil pressure switch...

The fuel pump primes so that you can have a quick start. After your engine is running (or just turning over with the starter enough to provide oil pressure) that switch is what turns the relay on and keeps it on as long as the engine is running. If you have jumped the relay and your engine runs then you have just proved that the oil pressure switch is needed.

 

No, the ECM powers the fuel pump through the fuel pump relay as long as there are reference pulses from the ignition module. The oil pressure switch is just a backup.

 

Doesn't it work that if the oil pressure is less than 7psi the pump won't run, and i believe if you have the sender unhooked it reads as 0psi?

 

No, it doesn't.

 

is that just on TPI or on TBI also, on my LO3 car I'm running a points distributor and the fuel pump runs whenever the car is running.

 

Its true on both TBI and TPI.

On your car the fuel pressure switch will be keeping the fuel pump running, since the ECM won't be happy.

 

My 90 V6 car ran two weeks with the oil switch jumpered while I farted around and waited to replace my oil switch.

It would not run with the oil sender unplugged...

 

You had other problems, then.

 

Just when I thought things were fixed!!!

Oh well, that engine went into an S10 a long time ago... and that was 4 firebirds ago!

More knowledge is better; thanks for the tip!!