I am having a crank/no start issue with a 3800 N/A(L36).

This fuel pump is installed
http://www.highflowfuel.com...fiero-1985-1988.html

I have spark, I have a pulse from each injector, the car WILL run on ignition fluid, but it will not start.

I can hear the pump turn on. Fuel flows freely from a detached line. When the fuel pressure regulator is removed and the car is primed, fuel fountains out from the hole where it should be(duh). Fuel flows during cranking. Fuses are good.

I rented a fuel pressure gauge:

When using the Schrader valve it was impossible to get ANY rating, during start or during crank.
When directly linked to the fuel supply line, the gauge showed 20 PSI during the first prime, and the second prime maxed out the gauge..

After trying to start for long periods of time, I can press the Schrader valve and I do not get the hiss/spray as the rail does not seem to be receiving ANY pressure...

Any ideas? I am getting sick of replacing parts. Vehicle has a brand new fuel pressure regulator and pump.

should read 45- 55psi of the fuel pressure.
make sure the wires are not reversed.
I bought a Fuel pressure guage from summit and installed it inline.

quote Originally posted by revin: should read 45- 55psi of the fuel pressure. make sure the wires are not reversed. I bought a Fuel pressure gauge from summit and installed it inline.

Anyway to test/switch this without dropping the tank? I really dont want to..

I just had this problem. The rubber hose in the tank from the pump to hard line split. Letting some fuel to flow but low to no pressure. Dropped tank replaced hose car fired right up . And my pump was brand new . Guess the hose they sent with it was crap.

quote Originally posted by Scott2scott: I just had this problem. The rubber hose in the tank from the pump to hard line split. Letting some fuel to flow but low to no pressure. Dropped tank replaced hose car fired right up . And my pump was brand new . Guess the hose they sent with it was crap.

Im going to try a wider quick connect hose on top first. Is there specfic type of hose to use?

quote When directly linked to the fuel supply line, the gauge showed 20 PSI during the first prime, and the second prime maxed out the gauge..

If this is the case, your fuel pressure regulator isn't working. Double check by putting a vice grips tightly on the rubber return line pinching if off. If you have pressure then, check your FPR.

Fyi , if you have fuel pressure then, it should also start.

quote Originally posted by phonedawgz: If this is the case, your fuel pressure regulator isn't working. Double check by putting a vice grips tightly on the rubber return line pinching if off. If you have pressure then, check your FPR. Fyi , if you have fuel pressure then, it should also start.

I did JUST buy a new one.. But I will use a spare vacuum cap and try this.

Yes I saw that. But the FPR is supposed to hold back the correct amount of pressure and bypass the excess fuel to the return line. If you have pressure when the return line is blocked (or dead ending the fuel pump into your gauge) but don't have fuel pressure when the fuel flows back into the tank, then the FPR isn't working.

Please do try blocking off the return line in the normal set up and see if that brings up fuel pressure. If so your FPR isn't blocking anything and just letting it all flow back into the tank. I would do the vice-grips test before condemning the FPR.

The one thing that doesn't totally mesh with this idea - On the first run of the pump when you were dead ended you should have gotten more than 20PSI. But maybe there was air in the line or something.



The FPR is designed to hold the fuel pressure at 48 - 52 PSI minus intake manifold vacuum. (or plus if the intake manifold is under boost)

[This message has been edited by phonedawgz (edited 06-03-2015).]

Oh you mean the rubber FUEL return line. Okay, will do.

I did crank it once with the return line totally off and nothing came out. Also after try to start a half dozen times I took the whole rail off and there was no fuel inside it at all(past the FPR). Does that achieve the same goal?

Ill redo the fuel pressure test. But am I correct in saying that I should NOT get any pressure from the Schrader valve if the FPR is blocking it?

If you have your pump output going to the FPR directly, then this is your problem. The pump/supply line should connect directly to the fuel rail. The FPR should connect to the return line.

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A little hard to see, but the fuel pump (3) in this picture flows fuel out of the tank in fitting (5) through the fuel filter (6) and into the fuel rail. The FPR (8) allows excess pressure to leak back to the tank via the fuel return line.

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There should be fuel in the return line. The system is designed that the fuel pump should be able to pump pressure beyond the FPR pressure. The FPR should always be leaking some fuel back into the tank in order to maintain the correct pressure. If the pump can not pump sufficient pressure, then the FPR would not open and there were would not be any fuel in it.


The FPR is on the OUTLET of the fuel rail, where the fuel flows back into the tank. The FPR can not block fuel from the pump getting to the test port. It only partially blocks the return. It does this partially thus maintaining the correct fuel pressure and leaking back to the tank.
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[This message has been edited by phonedawgz (edited 06-03-2015).]

Oh my god I am an idiot.

My stock FPR on the stock fuel rail was half clogged with some crap. remove it and look to see if all is clear.
I think it is a snap ring holding it in.