Fuel pressure with FMU? (SN89)
I have a 89 Mustang LX with an SN89, Paxton AFPR, 24 lb/hr injectors, and FMU.
The aformentioned parts were installed by the previous owner and I've been slowly but surely undoing his installation and tuning mistakes.
Today I finally got around to checking the fuel pressure at idle and it was 62psi :eek:
I dialed it back to 40 psi and the car seemed to idle slightly smoother. My question is why would the base fuel pressure need to be that high? I don't have any info on the FMU, but it looks like it has a small release valve/knob on it.
Any thoughts are appereciated. thanks