LB7 code 0090 trouble shooting and diagram needed

[toddster911]

started a new thread as the other was going in the wrong direction, My loping and high pressure problem seems to be electrical. The fpr is good, no blockage and read 3.2 ohm's, same as a new one (tested)I would like to follow my wires to see if there is a break somewhere or trouble shoot electrically.

does anyone have the diagram and/or test proceedure for ELECTRICAL high fuel pressure....all my mechanical is good, fpr is mint anfter removal...0090 code is present-electrical

thanks

 

[Sledhead]

Did you run the truck with the new fpr?

 

[toddster911]

Ran it last night, same symptoms.
I used the original cause I had a fpr modifier took mine apart to check for scoring or jamming, all was good and compared it's resistance to the new one, same. He said in 5 years he has only ever changed 1 FPR, but modified a bunch with shims.

does anyone get other than 3.2-3.5 ohms when measuring the sensor itself?

the 0090 code comes right back instantly when I clear the code, either way the loping and clacking are present at all times.

I read through the gm troubleshooting list and they point twards ecm...but I don't have the proper scanner to check rail mpa etc. I am at witts end and need my truck running yesterday so I guess I will have to bring it to that shop that tested my FPR for a proper scan and diagno$i$...hope for the best and expect the worst!!.

dunno....

 

[czmwyte]

Have you found out anything new i have been having the same problem i changed my fpr twice thinking maybe the new one was bad and i changed the fuel pressure sensor and i got a new ecm and im still having the same damn codes this truck is killing me i do t know what else to do i previously had the wite harness rebuilt about 6 months prior to this episode that has had me out of a truck for the last 6 months trying to figure this out any help would be great