ok, so I have changed all the o rings on my 88 GTA, and the pressure bleeds off from 50 PSI to 10 PSI within 5 seconds after turning the car off. New fuel pump, and fuel filter as well. should I try swapping my AFPR?? if it is the injectors, can I put a bigger pound rating injector on a basically stock 350?? I can get a great deal on a set of 30lb, thats why I ask. Thanks in advance fellas

 

To check if the injectors are leaking unbolt the 4 bolts on the fuel rail and lift it up enough to see the bottom of the injectors. Turn on the key to pressurize the rail (do not start!) See if you have any leaking injectors. If you do repace them.

Q2. You will have problems putting in the larger injectors, you will run wayyyyyyyyyyyy to rich, unless you get into prom burning or know someone who does to reset the injector constant to match the new injectors.

 

You can try to pinch off the return line hose and then the pressure hose to see if it holds pressure . I used small pieces of gas line on a pair of needle nose vice grips to keep from damging the hoses, If it still bleeds off with both hoses pinched off at the same time it's the injectors

 

just as albert said, start the car and pinch the return, now as soon as you pinch the return the pressure will go up to around 80psi(deadhead pressure) now pinch supply and shut the car off. it helps with a buddy. if pressure drops, bingo, its the injectors leaking, but if pressure holds then it could the pulsator in the tank, to test it, release the return line, does pressure hold? it should. if it does, release the supply you have pinched. if the pressure drops when you release the supply, it is leaking back through the supply. trust me, my car is doing the exact same thing!! mine is the pulsator leaking, but i am going to replace it with a piece of hose this weekend. are you having any drivability probs or long starting probs?

 

With my old fuel pump, even when I pinched off the line the pressure would bleed rather quickly. With the new pump, the pressure held... for a while. Now it's bleeding off again. I think it's just a fact of life that sometimes these pumps like to bleed down.

 

mine drops to zero as soon as i shut it off, in less than a second. should never bleed that fast

 

guys im having this same problem with the new holley/walbro fuel pump I put in, and sometimes it takes a few cranks for my car to start. Is there any solution to fixing this pulsator problem? Thanks

 

Johnny I have the same fuel pump as you. I haven't done any diagnostics yet but if yours is leaking back I bet that's my problem also. How do I go about checking that again?

 

hmmm, I never would have though about the fuel pump...good call fellas, thanks!! I'll check pressure this weekend and keep you guys posted. Thanks again, I hope one of these works!



bubbz89-
It was having a really hard time wanting to start before I swapped o-rings last Monday, but since then has started right up like a champ. Idle does fluctuate a little, but that could be another problem.

 

you can remove the whole pulsator and just put a piece of rubber hose where the pulsator was, i am doing it this weekend, i will let you guys know how it works out.

 

I have identical problem. When i turn off the fuel pump the pressure bleeds off instantly, straight to zero.

I have the WALBRO intank pump, and an aftermarket regulator.

I think its just the way the pump was designed. i cant see it affecting your starting since the pressure rises instantly when the pump kicks on.

 

well what happens is, when mine primes it takes like two times to get up to 45psi becuase the puslator is leaking that bad. when i have a full tank, starting is always easier.