Emergency HELP Please F53 Fuel problems
WE are stranded in Grants Pass. We broke down near the bottom of Sexton Pass on I5 on the Saturday of the Laborday Weekend. No Tow Trucks were available and we had to stay in the rig overnight 4 fe...
Forum Discussion
Gnarley wrote:
I can't imagine what may be causing the loss of pressure when it's hot and the engine controls sense the need for more pressure and you can see it drop on the guage.
That's what made me suspect a vacuum issue. The FPR is controlled solely by engine vacuum. When vacuum goes down, fuel pressure should go up. But if it's missing vacuum, the PCM will compensate via the O2 sensor, but it doesn't respond fast enough to to "un-compensate". Whenever I've run into this, I use a hand vacuum pump with a gauge, and verify fuel pressure is responding correctly to change in vacuum. Autozone should have both on hand to loan out for free. A collapsing vacuum line can also make cause similar problems.
Do you have any other symptoms of a mass vacuum leak? Does your A/C come out the vents rather than the dash?
A stuck EVAP solenoid can also cause weird symptoms, becuase it draws too much vacuum on the tank. This one is easy to diagnose.... Try driving with the gas cap cracked next time it has issues.
