Fuel Pump Voltage?

[racin4ds]

As many of you know I've been chasing a fuel issue with my relatively stock 03 Cobra. I've already replaced both pumps, replaced the lines in the tank with gates hose, deleted the PPRV, had the PCM reflashed by Ford etc. I still have very high FPDC% and can't figure out why.

Last night I took my voltmeter and backprobed the fuel pump feed wire at the connector in the back above the tank, I'm getting 13.0-13.4 volts there at idle? Shouldn't this be much lower voltage at idle? I'm thinking my FPDM could be going haywire and supplying too much voltage to my pumps causing my high DC%

Any of you guys ever check your voltage at this connector or at the pumps? What do you get at idle? :shrug:

 

[racin4ds]

TTT someone has had to check this! Does anyone know what there voltage is at the pump?

 

[2001Snake]

Im interested also....I would think it should be lower also??

 

[JaCobra]

Same question here

 

[bigmoose]

have you datalogged or measured your fuel pressure? The computer will command whatever voltage it takes to get the fuel pressure right at the rail.

A bad FRPS could be seen by the ECU as low pressure, causing it to command a high voltage at the pump. I just had mine go bad and i could tell because the vacuum reading from the ECU was around zero at idle due to the fuel in the lines. you can also tell its bad if there is a difference in the ECU reading and the physical measurement off the valve on the rail.

Have you tried swapping out the FPDM with someone elses?

 

[Quagmire]

Check your FR press, and look at duty cycle. Post results.

 

[EvilBlack]

Any progress on this? Subscribing as well.

 

[r103]

Has anyone eles checked voltage at the pumps like this?