Hey all, I replaced my fuel pressure regulator and now the truck won't start.
2000 4.3L 4X4

I replaced the FPR and got it to start after a couple tries, then it stalled. I immediately started it again and it started revving high so I shut it off, waited a bit and started it again. It idled kind of rough for a while so I revved it myself until it smoothed out and I thought all was good. I turned it off and went in the house for a while and came back out later for a smoke and decided what the hell I'll start it up again - nothing. Cranks forever but will not turn over. Seems like its getting no fuel.

My main question is; could I have got a dud pressure regulator? Or maybe one of the fuel line o-rings got jammed down in the spider?

Before I take everything apart I was wondering if this has happened to anyone else.

I'm not going on a wild goose chase and I know my pump is good. So is there anything I could have done with the plenum off that would cause this or is it likely a bad regulator?

Getting sick of this truck...those fuel lines were so friggin hard to get back in with that stupid bracket clip to hold them down.

Thanks

 

Stop guessing and start with the fuel pressure test that appears as a sticky at the top of the second Gen forum. Report all four values and we will help you.

 

I will try to get the pressure gauge today, but I have a new fuel pump and it was working fine before i changed the regulator so how will that help? I'm just curious. If the leakdown test fails or the initial pressure fails will that indicate the something on the engine side because I have a newer pump?

 

If you do the tests exactly as written we will be able to evaluate both the fuel pump and fuel pump regulator, and if there is a problem we will be able to tell which one is at fault. If no problem with either one, then that will become apparent and we can move on to other things. Note that one of these tests requires you to dead end the pump ahead of the injector spider, not afterwards. Instructions are given for doing this and suggestions for making up the required fittings are given. Don't try to do this by blocking flow out of the fuel pressure regulator or you will likely damage it. Hope this helps explain. Have you read the testing instruction sticky carefully? Do you have any further questions before proceeding? Best wishes for a successful repair. Les

p.s. if you have the upgrade MPFI spider, the normal pressure with zero vacuum and pump energized is around 58 psi in my experience. Don't get hung up on the 60 psi minimum in the sticky - that is apparently for the original poppet style injector spider assembly.

 

One more thing. I really should ask the history on your problem. It might help us understand better. Why you replaced fuel pump and replaced fuel pressure regulator in the first place? What problem was you trying to fix? What were your symptoms? How did you test? What brand of fuel pump did you install? Stuff like that.

 

Hey sorry got a bit distracted by other stuff for the week. I couldn't get a fuel pressure tester and needed the truck running, so I put my original FPR back in and it starts again (after a few tries).
Just to answer your question for the sake of info:
my original fuel pump died 2 years ago so I replaced it (no question about it, the fuel pump died). I had bought an airtek replacement and let's just say I am a pro at dropping the tank now and changing fuel pumps and will never buy aftermarket parts again.

What led me to the FPR was poor starting, especially when cold or raining (if that matters). Smelled gas only at front end sometimes. My oil dipstick smelled like gas. Sometimes rough idle or poor shifting in lower gears and then finally when I took the intake off it was nice and clean towards the back of the injector.


I think the FPR i got was a dud, working on getting my money back and then it's off to find a new vehicle. I'm sick of putting bandaids on this one, especially every time winter comes. 280 km is a lot of life and I got 8 years out of her, so that's good.

 

Oh and those aluminum fuel lines from the nut kit are a god damned nightmare to put in. I stripped a bolt from the bracket that holds them in. Stupid truck. Even thinking about it stresses me out.
And I meant behind the spider, not injector.