WICobaltSS

Hello,
I've been having issues for some time now with running rich and stumbling on start up or even stalling issues if the car sits for a few days. I replaced the fuel pump last year so I don't think that is the case. Anyhow, I did a fuel pressure test and it was at 65 PSI with no change when I snap the throttle. Some sites show the 2.2 L at 55-60 PSI, so I don't know if my reading is considered high. When I shut it off, it will drop 10 PSI in about 5-10 minutes. The LTFT hangs at about -10 to -12 at idle but goes back up when accelerating. What should I check for as the possibilities?

Thanks,
Jason

steelmesh

I would agree that high fuel pressure without the ECU knowing would cause LTFT to drop because the ECU is calibrated to the lower pressure, so a 1 ms injector pulse would flow more fuel at higher pressure. I think there is a fuel pressure regulator on the fuel rail, so you might want to look into swapping that to see if it reduces your fuel pressure into spec.

Otherwise check codes and check for dirty plugs, dirty MAF, bad oxygen sensors.

WICobaltSS

Thanks Steelmesh! The Oxygen sensors are new, but the plugs may need replacing. I almost forgot to mention, I had a ZZP shorty header and catted downpipe, but switched back to the intake manifold and a new aftermarket downpipe and cat. Would that throw things off?

Slowbalt2000

iTrader: (1)

Fuel pressure regulator is in the fuel pump canister, not the fuel rail. 65psi is a little high, it should be 58.

steelmesh

I was googling around where the FPR was, but then starting seeing a diaphram widget on the fuel rails and ASSumed it was the regulator portion, what is that anyway?

Slowbalt2000

iTrader: (1)

My understanding is that is a pressure pulsation dampener.

WICobaltSS

I was googling around where the FPR was, but then starting seeing a diaphram widget on the fuel rails and ASSumed it was the regulator portion, what is that anyway?
That's what I thought too. I'm going to disconnect the battery in hopes of resetting the computer to see if that helps. If not, then I will have to go from there...