Dropping fuel pressure reasons? (Page 1/1)
tnkgnr AUG 05, 04:13 PM
Hello all,

I have a 3.4l pr that gets to the correct fuel pressure when the system does the initial fuel pump activation, but will rapidly lose that pressure over 10s of seconds.

I replaced my injectors thinking one was just leaking, but the problem remained. At that point I pulled the whole fuel rail again and observed when I charged the system that there were no leaks from the injectors. The cold start injector has been removed/plugged.

Is there a check valve somewhere that I'm missing?

Thanks for any suggestions/info,

Greg
theogre AUG 05, 04:47 PM
FP has a check valve or regulator valve and either/both can leak...

Gauge attach to engine...
Run FP, Pinch Rubber section of return line then Quickly shut off FP. Watch gauge.
No Drop then do same but w/ supply line.

Do Not run FP w/ lines blocked or quickly overheats and doesn't last long. Best to have help to block line then kill power fast.

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave

Gall757 AUG 05, 04:48 PM
The fuel pump assembly can be leaking inside the tank. Probably a bad hose.
Patrick AUG 05, 04:51 PM

quote
Originally posted by Gall757:

The fuel pump assembly can be leaking inside the tank. Probably a bad hose.



From Here.



[This message has been edited by Patrick (edited 08-05-2020).]

tnkgnr AUG 05, 06:37 PM
Oof...that sounds fun. I've been thinking about dropping the tank anyways, since I've got a fuel gauge that reads right, but wanders back and forth on turns/stops...think I've got a problem with the baffles or the bobber thing in there.
theogre AUG 05, 08:41 PM
Bad hose would prevent FP even make a few PSI when on and can't run the car most times.