Lean AFR with fuel rail pressure sensor plugged in

[dhardison]

I have a '00 Focus ZX3 (Zetec). I started having problems with the engine idling rough and running very lean. I put a gauge on the fuel rail and noticed that whenever the fuel rail pressure sensor is plugged in, I have ~40-50psi and the AFR is lean (and engine will stall). If I unplug the FRPS the fuel pressure goes to 70-80psi, the AFR goes to normal (14.7:1) and it idles/runs great.

It's throwing the following code:
P0193 - Fuel Rail Pressure Sensor Circuit High Input (FRP) The comprehensive component monitor (CCM) monitors the FRP sensor circuit to the PCM for high voltage. If voltage were to fall below a calibrated limit and a calibrated amount of time during testing, the test will fail. FRP signal shorted to VREF or VPWR.
FRP signal open (gasoline only)
Low fuel pressure (NG only)
Damaged FRP sensor.
Damaged PCM.
High fuel pressure (caused by damaged fuel pressure regulator) NG.
A FRP PID value during KOER or KOEO less than 0.3 volts for gasoline or 0.5 volts for natural gas vehicles (NG) would indicate a hard fault.


I've replaced the FRPS but no change. Any thoughts?

Thanks,
Dan

[discnik]

Just because it is a new part does not mean that it is a GOOD part. Been running into that recently. First check the ground wire in the circuit for continuity to vehicle ground. Also check connection at PCM for looseness, corrosion, or water contamination. Had a Ford Freestar with same code and it was the FRPS. Hope this helps.

[rivguy]

you will get a high input if you don't have a pcm ground circuit also, not just from a failed sensor. is this the only code in the pcm?