LB7 fuel pressure sensor

[55shoebox]

I would like to check my fuel rail pressure sensor does someone have the specs on how to check it (ohms). If possible is there a way to check the fuel regulator / solenoid?? I think i have reduced my problems to either of these and was hoping to check them besides just replacing the parts. Thanks Tracy

2001 lb7

 

[scramHD]

Only way I know to check it is with a TECH II or EFI Live. I am guessing your talking about the fuel pressure regulator.

If it was a sensor, you would light a CEL.

 

[2500HeavyDuty]

to test it disconnect the FRP sensor with the truck runnin and observe the RP, if it goes higher than 175MPa then replace the FRP sensor.

idf it dont then thee might be a short to a ground in the wiring for the FRP sensor.

 

[scramHD]

Uh, hes got to have TECH II or EFI to observe rail pressure right? Dont think he has the RP gauge.

What symptoms is the truck having?

 

[2500HeavyDuty]

Uh, hes got to have TECH II or EFI to observe rail pressure right? Dont think he has the RP gauge.

What symptoms is the truck having?

yup one of them

 

[sweetdiesel]

Ask Henry if he hasnt allready posted it Look in the GM specs section

Look for big flucuations in the milli amps of regulator Des VS Actual

 

[55shoebox]

The truck runs ok at idle but as soon as you roll onto the throttle it stumbles and feels like it is dropping cylinders. I have changed injectors - primed the fuel system ALOT and have had several people try to figure it out with no luck. I don't have monitoring equipment, or a pressure tester for that high of pressure. I have had several people tell me the next thing to check would be the rail pressure sensor or the regulator on the pump. Any help will be appreciated - Is there anybody on here that is in SE WA state that i can bring the truck too?? Thanks Tracy

 

[radvans]

fuel filter

 

[radvans]

Normally a bad fpr will have a slight surge at idle and be fine when driving.

There are some handheld tuners that can show rail pressure, ppe for example.

 

[2500HeavyDuty]

changing out the fca with a new one might help

 

[55shoebox]

Yeah changed the fuel filter twice cut them open even first one was pretty funky next one was clean. FCA ? dont know what this is - i am kinda a newbie to all the diesel terms. I dont have a tuner or really know anybody who does - if i need to take it somewhere i will, any help and or suggestions will be help. Thanks Tracy

 

[2500HeavyDuty]

FCA is commonly referred to as the fpr. its on the cp3 it has 2 wires coming out from it

 

[onebadduramax]

to test it disconnect the FRP sensor with the truck runnin and observe the RP, if it goes higher than 175MPa then replace the FRP sensor.

idf it dont then thee might be a short to a ground in the wiring for the FRP sensor.

do you know where the ground is for that wire?

 

[JSmitty]

Im currently having the same issue, Did you ever figure out what fixed it?