LMM: CP3 Knocking HELP!

CaptPhil

Active member
Sep 10, 2011
1,012
0
36
Delaware
Well here's an update. Unhook top pump take belt off noise goes away . install belt back on hook back up knock comes back...unhook Lift pump noise goes away. Idles fine for more than 30 seconds. Reflash ecm to previous stock injector file start truck no noise. Reinstall 100 over tune start truck immediately says reduced power upon key turn starts up pump knocks u hook lift pump truck acts as if it's going to die....tech 2 go command rail nothing happens....clear dtc go command rail 13k is all you can get. At idle rail won't meet desired. Rail plug is tight as a dickens in there with an impact . at this point I'm blaming the controller. I rewired the leads for it on the battery just to say I did. Truck doesn't want to run right acting like it wants to stall and buck with the lift pump on and working now. Reduced engine power every key on. Drives ok otherwise. What else could it be besides this Damn controller ??

Have mark build your tunes off your original stock injector file if it idles fine and sounds fine with it loaded. Sounds like a corrupted file to me if the original tune doesnt do it.
 

TowU4Free

#SecretSquirrel
Aug 27, 2011
469
5
18
Well last night it wouldn't run right on any file. Kept throwing reduced engine power regardless soon as you keyed in p0087
 

TowU4Free

#SecretSquirrel
Aug 27, 2011
469
5
18
Yea, its very odd to my why after loading the 2nd tune now it goes to reduced power regardless of any tune. I did take the injector flow rate for injector 1 and copy that info into all 8 injectors in the ecm and copied to the gpcm, first spin out after that it through codes for 2-8 being calibrated wrong? Wouldnt let me erase codes even with tech 2. went through and checked it a few hours later and it let me erase them and they havent showed back up since! This thing is a gremlin
 

TowU4Free

#SecretSquirrel
Aug 27, 2011
469
5
18
Yea, at this point im thinking thats my best bet, I talked to someone at PPE yesterday about this issue and really didn't have a pleasant experience. He mentioned the pump starving for fuel making the noise....with 12psi positive pressure??? And unhook the lift pump it goes away, cmon now. Anyone know of someone in particular i should contact at PPE? I bought the kit used so i doubt they'd warranty anything for me but it never hurts to ask.
 

TowU4Free

#SecretSquirrel
Aug 27, 2011
469
5
18
I have a sensor on the filter housing where the bleeder screw used to be, been that way for over a year now.
 

Slowmax

Build what others' won't
Aug 3, 2013
468
0
0
United States
Yea, at this point im thinking thats my best bet, I talked to someone at PPE yesterday about this issue and really didn't have a pleasant experience. He mentioned the pump starving for fuel making the noise....with 12psi positive pressure??? And unhook the lift pump it goes away, cmon now. Anyone know of someone in particular i should contact at PPE? I bought the kit used so i doubt they'd warranty anything for me but it never hurts to ask.

Call and ask for Dan see if he won't set you up with what you need.
 

TowU4Free

#SecretSquirrel
Aug 27, 2011
469
5
18
Its funny you mention that, I just called and left him a lengthy message. I explained that i bought the kit used off someone so i didn't expect him to warranty the product for me but figured it didnt hurt to ask and that any assistance he can give me would be appreciated, We shall see!
 

TowU4Free

#SecretSquirrel
Aug 27, 2011
469
5
18
Im counting on that. however the part about the inconsistancy with the lift pump really confused me. sometimes truck wants to die right away when unplugged and sometimes it will run for a while.. Maybe the controller is commanding the cp3 to ask for more fuel from the tank off an on??:confused::confused::confused:
 

56taskforce

Well-known member
Mar 30, 2014
1,074
51
48
I am thinking the 12 psi may be too high. I swear I read somewhere in my FASS paperwork that 10psi was max for a CP-3s inlet pressure.
This would explain why it goes away for a moment when the pump is unplugged. If there is a adjustment on your lift pump try turning it down too say 8psi...
 

CaptPhil

Active member
Sep 10, 2011
1,012
0
36
Delaware
He shouldnt have any problems considering his truck is an LMM. Only the FICM equipped trucks had issues with high lift pump pressure causing the FPR to freak out.

You could try turning it down a touch though and see if it helps.
 

Yngdmax92

Active member
Sep 26, 2013
962
44
28
did you ever run the truck with out the belt? I keep thinking back to your statement that you said the noise changes with the A/C.
 

TowU4Free

#SecretSquirrel
Aug 27, 2011
469
5
18
Captphil is correct. No ficm on lmm , but I ran it this way hell even at 16psi for months with dual pumps and stock injectors with no issue. Wish the controller would scurry along and get here
 

56taskforce

Well-known member
Mar 30, 2014
1,074
51
48
He shouldnt have any problems considering his truck is an LMM. Only the FICM equipped trucks had issues with high lift pump pressure causing the FPR to freak out.

You could try turning it down a touch though and see if it helps.

It seems to me what I read was for my LBZ which is post FICM. It is a stab in the dark but I couldn't help thinking about it when he stated the knock would go away before dying when the pump was unplugged.
 

56taskforce

Well-known member
Mar 30, 2014
1,074
51
48
Captphil is correct. No ficm on lmm , but I ran it this way hell even at 16psi for months with dual pumps and stock injectors with no issue. Wish the controller would scurry along and get here

Try it see what happens it is a stab in the dark but what have you got to lose? You obviously have visited this anyway you unplug the lift pump and it went away then dyed. That in it self point too excessive inlet pressure.
 

TowU4Free

#SecretSquirrel
Aug 27, 2011
469
5
18
Dropped it down to 11 last night. Thursday I'll get the fingers controller I bought used off here and try to get back at it with that