Ok, last summer my car had really hard warm start problems, and my idle was slowly getting worse. Well I sent my injectors away to rich@cruzinperformance and he fixed them (Found some leaky injectors too). I had them all cleaned and flowmatched.


So I put the car back together. Starts great!, idles like glass, great throttle response, drives great, I was very pleased. I also checked for vacum leaks which I am very sure I don't have.


Well before when I hooked up a fuel pressure gage it stood steady at 36 psi at idle. Well now when I hook it up, its at 36 psi, but it is jumpy. Not jumpy as in jumping from 36 to 38 psi or anything like that. But the needle wiggles a bit instead of staying steady. Is this a sign of the fuel pump taking a poop?

If I hold the rpms at around 3-4K, the needle stays steady.


I made a movie if anyone wants to see what Im talking about.


Thanks

 

if you turn the key on-engine off and let the pump prime the injectors....how long until the pressure bleeds off the guage? i'm thinking it might be the return side of it doing that. Also.....by removing the vacuum line going to the pressure regulator does the fuel pressure jump up about 10 psi or whatever and stay steady? it might be detecting the injectors turning on and off, although i've never seen it on my vehicles. hopefully someone else will chime in as well to help you out.

 

The pressure holds fine after turnoff, that was fixed with the new injectors. And I do get a solid 45 psi with the vacum line unplugged.


You know if you put your finger on your injectors how you can feel them pulsing? You can feel that a little when holding the gage in your hand. It seems to bounce with that...

 

are you getting any stumbling or hesistation that makes you feel that the pump is dying? any louder or whining noises from the tank? otherwise i would say it's normal enough to not worry about it.

 

Nah it drives great. It was just making me nuts because before the needle would not move at all. Then I put it on there now and its bouncy. I didn't do a WOT run yet since I put it back together though.

 

Yes, you're probably being paranoid. You and Ozzy - Geez...

Anyway, the FPR is probably teetering on the edge of pressure regulation with the vacuum line connected. Since the pump (and regulator) will hold a steady 45 PSIG with no vacuum, the pump is probably just fine. The vacuum diaphragm and linkage may be a little funky in the FPR, but it obviously isn't causing a problem.

(I can't load the video clip - maybe the server is too busy?)

 

Thanks Vader


The clip works for me. Maybe if you right click and save target as it will work for you.


Do you know how good it feels to actually get in my car, crank the motor one time and have it fire right up?



[Edit] - Lol I don't know if I didnt have my gage hooked up to the valve good enough or what. But I just ran the car three times for 30 minutes and the needle stays absolutley still like it used too


Thanks for the replies guys!