The fuel pressure staying at 37-39 PSI, and spiking after a WOT run, is normal in my experience. Hey graywave! What were you generator codes? 13.3V sounds a bit low for this system, since desired is usually 14V. Not sure if these symptoms line up with a bad FPDM I know these have huge common faults with the Fuel Pump Driver Module Corroding. Depending on if I can put time into this issue, I'd like to T my fuel gauge into the system some place to get mechanical readings.

I am wondering what ACTUAL fuel pressure should be under load and at idle. I'm used to looking for 50-60PSI but this system specs at much lower pressures. 86% on the labscope would be 14% command to the FPDM? I didn't try swapping my leads around, thinking that possibly my NEG and POS lead on the scope should be swapped to get a different % or maybe that wouldn't matter.īasically I am a little new to this system to be honest. I am thinking that maybe I should be reading this the other way around.

Now this confuses me as I was expecting this to be low and INCREASE. PCM to FPDM Control Signal Starts at 86% and drops as load increases. FPDM Return Fault Signal Wire: 50% at all times. The initial instantaneous romp on the throttle, both Upstream and Downstream O2s will read full lean for a second till the truck starts accelerating.įPDM Fault Return Signal Wire (PIN 30) and PCM to FPDM Control Signal Wire (PIN 62) probed at PCMġ. Bank 1/2 Upstream O2 Sensors will NOT read rich during WOT until the FRPS reads 49 PSI. At some point, usually just as I let off the throttle at the end of my WOT run the FRPS will spike to 49 PSI Fuel Rail Pressure Sensor PSI at WOT: 37-39 PSI Fuel Rail Pressure Sensor PSI at idle: 37-39PSI NOTE: Vacuum line connected to FRPS during pressure readings Last voltage test I saw was 13.3v at idle Only Generator fault code which could be a cause if voltage drops. Slightly Rough Idle - Some light misfires on all cylinders which I can only pick on the the cylinder contribution test on the scan tool. My knowledge is a little low on fords FPDM fuel system.

Ive been doing some tests to familiarize myself with fords FPDM fuel system. I have an 2007 Ford F150 which has hesitation and misfire which was not brought here for this condition so the boss may not want me to put much more time into it.

2005 ford f150 lariat fuel pump module