Question: Proper way to test CP3???

[joeracer01]

What is the proper way to test the CP3 on a 03 GMC Duramax with EFILive?

Which PID's should be looked at?


Attached (i hope) is a log.
Not sure I loooked at the rigth stuff.
Please look at it and let me know.

TIA

[mijdirtyjeep]

I would say it is not looking good for your CP3 "desired 160mpa, and you are only getting 90.4mpa".

Also looks like your FPR is on the way out as well, is your truck surging at idle? How many miles on the injectors? I did not see the balance rates on them!

The only other test would be a return rate test, to rule out bad injectors returning too much fuel.

PS: I just replaced one in a truck though that had about the same Desired vs Actual Mpa's and it solved the problem.

[joeracer01]

119k miles on injectors
Injectors are within spec at idle truck warm in park.
#4 and 5 are border line but under 4.
Injectors while in Drive with brake pedal pressed are in spec except # 4 and 5 are at 6+ at times but not constant. They bounce in and out.
I get white smoke here and there also.

No surging at idle or anywhere
No lope
Lines all seem to be kink free and none are collapsed


Getting a P1093 code
Code only started popping up after I installed a nicktane filter adaptor with a cat filter.
Running a Hypertech 90hp tune

It was suggested to me to do the shim kit for the FPR
It was also suggested to me to do a lift pump

I don’t want to waste $ on a lift pump if what I really need is a CP3

[THEFERMANATOR]

With that many miles on your injectors, and from the looks of your balance rates. I would say your injectors are GONE. Injectors WILL cause a a low rail pressure code as well as a failing CP3, or a restricted fuel supply. You need to do an injector return rate test to verify this though.

[joeracer01]

Logs

Stock Tune
Nicktane adaptor still but, now modded by me for more flow
NO CEL as of yet
Have not been able to drive the route that would always make the CEL come on

[joeracer01]

Put on a stock fuel filter
Still get P1093

Then I shimmed the FPRV (PITA)
It looks like it helped the balance rates for INJ #4 and 5 while in drive.

Check the logs and let me know what you think.

I think the CP3 needs to be changed.

9170

9169

[THEFERMANATOR]

Until you do an injector return rate test there is no way to say with certainty that the CP3 is bad. And you have to remove some of the fuel lines to do one as it isn't an electrical test. Don't feel bad though, I'm in the same boat with injectors that are only 14 months old.