Its been going on for a while now and dont know what it could be. At idle target idle speed is met, sometimes at a stop light or just parked my idle increases Id say 150-200rpm. sometimes I rev it and it goes back to normal sometimes just stays. Now I have a fuel pressure gauge and at idle I get 50psi and normal cruise. When my idle problem begins pressure is at 59psi,this is even at a dead stop. Now my question is can the fuel pressure regulator going bad cause this?
Thanks


Jaime

 

A fuel pressure regulator that is vaccuum referenced (VRFPR) the fuel pressure will be lower when there is high manifold vacuum, like when idling and cruising. When revving or when at WOT, the fuel pressure will rise as manifold vacuum decreases.

Sounds like your FPR is working fine. Try unplugguing the vacuum hose, the fuel pressure should rise from low 50's up to 60psi.

peace
Hog

 

Well when I do that it does raise the fuel pressure, but what would cause a vacume loss at idle ? Ive sprayed throttle body cleaner to see if I have a manifold leak and nothing. What would the cause the Idle to raise while at park or drive at a stop? I am loosing vacume I can see it when my fuel pressure is at 60psi and at a dead stop.Cna the FPR act up? If not the quest will continue. Thanks

Jaime

 

Bump. I'm having a similar problem. Spec at idle for my 00' is 55-62psi btw

 

Yeah, having the fuel pressure at 59psi at idle is weird, it hsould be closer to 50psi.
Maybe your regulator is on the way out.

peace
Hog

 

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