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Discussion Starter · #1 ·
I recently brought my truck through a bit too much water and mud my truck was overheating due to a clogged radiator intercooler etc. i pulled all of them out Trans cooler puller cooler and all and pressure cleaned through both sides making sure not to bend the fins. Overheating problem is fixed and now I'm having trouble with engine power., using my ppe hot plus 2 i determined all of my balance rates are within spec in neutral and in gear with brake applied fully. My truck will start and idle pretty smooth and even +/- 20 rpms. My only problem now is my desired fuel pressure and actual pressure are dead even but neither break 13k I understand that desired should be in the 24k ball park and i know what could cause the Actual to nor be up there but i don't know why the desired isn't making it any help would be great
 

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Discussion Starter · #2 ·
Also no smoke from exhaust or breather. No diesel in oil and no raw diesel smell from exhaust or puff puff puff from my oil fill. The truck goes into limp mode and has almost no power and has a knock under regular driving conditions and knocks when it is given more then half throttle and when revving down from +50% Throttle
 

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That sounds like mine when the CP3 or regulator shit the bed . I dont know which was bad but at that time I was so frustrated with the EGR and the other issues I was having I decided to get a LBZ pump ,regulator and EFI live from ATP and turn off the EGR use robs tunes for LBZ regulator in LB7 and never looked back ..the truck is stuped fast now for a big ass truck . I couldnt Imagine have a built tranny and a few more goodies
 

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I was thinking maybe you got water on the regulator harness/plug but im pretty sure that would throw a code .
 

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Discussion Starter · #5 ·
I definitely got every single thing wet and when i got back i had 20+ codes i cleared the codes and the only one to chine back was a p0622 generator circuit is all it says
 

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Discussion Starter · #6 ·
Come back*
 

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Discussion Starter · #7 ·
But either way shouldn't the desired be going up with more pedal it stays at 13k but the truck will rev and hold that at 3250 with the actual pressure dead on what can cause it to only ask for 13k but still let it rev out An engine limp stops it at 2000 rpm I'm told. If you know anyone on the forum that might be able to help send them my way I'm new on here
 

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You need someone with a tech tool to plug in and see what the problem is
 

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Had the same issue on my truck and needed a new CP3
 

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Discussion Starter · #10 ·
But even with a bad cp3 isn't the desired rail pressure going call for more? And i can go to the stealership for a tech 2 But i don't feel like having them say well first we will change the regulator then the fprv then the cp3 O it was injectors the whole time lol i need a tech 2 and someone who knows what they are looking at which is rare around ft Lauderdale only local Ford and dodge mechanics around no one toucheS dmaxs at least that i can trust
 

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Could be a problem with the map sensor or MAF, you'd think you'd see a code though for those. It seems like it is stuck in a reduced power mode which will limit fuel pressure to keep the power output down.
Is your alternator outputting the right voltage? that generator circuit code has me thinking this is an electrical/sensor issue and probably not hard parts. Having the wrong voltages will cause all kinds of hell with these trucks, everything from tranny issues to no power and no starts. I would start with your alternator.
 

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Could be a problem with the map sensor or MAF, you'd think you'd see a code though for those. It seems like it is stuck in a reduced power mode which will limit fuel pressure to keep the power output down.
Is your alternator outputting the right voltage? that generator circuit code has me thinking this is an electrical/sensor issue and probably not hard parts. Having the wrong voltages will cause all kinds of hell with these trucks, everything from tranny issues to no power and no starts. I would start with your alternator.
I agree with this guy too . I didnt even put the 2 together but I think he might be on to something because I know for a fact even a weak battery or a mediocre ground can wreak havoc on these trucks . check all that out try to make sure everything is dry .
 

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one more thing could you have possibly loosened the battery cables removing the radiator or something when you were cleaning that stuff out . Oh and when you get time can you tell us the story of how you took the truck under water and why .
 

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Discussion Starter · #14 ·
Well i have a cj5 With 20 inches of lift i had at mudfest and my transfer case Went on that soi was don't a Lyle mudding in my truck and when i accidentally drove through some water over my hood and Didn't get stuck i, got slap happy and did it a few more times for some titty flashing lol ahh the things we do
 

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Discussion Starter · #15 ·
So i went and did a little mudding*
 

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Discussion Starter · #16 ·
My dash is reading,14 volts steady while idling for 30 minutes. I remember now that after my truck got wet it still had power even After sucking in the water and mud. It wasnt until i let the truck sit for a week or so until i got time to fix the overheating problem that i noticed the loss of power. Maybe something had time to saturate while it was down and is now bad. Waldo truck keeps throwing the same code p0621 generator field circuit is all it says. And does anyone know what the injector pulse width should be at idle?
 

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Start looking for loose wires or water in the connectors, pull the MAF sensor and the MAP sensor and look for contamination and water in their connectors, You might be able to reach the FPR plug and see if it is wet. I'm pretty sure something is shorting or contaminated. Could also be an injector shorting with higher drive voltages as the engine needs more power.
 

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Discussion Starter · #18 ·
Makes sense i checked every plug i could see except for maybe the map and fpr where exactly could i see the fpr plug? I've never seen a cp3 out or where it is ago id im reaching blind idk what to feel for
 

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Discussion Starter · #19 ·
So if I'm reaching*
 

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right down in the valley at the front of the motor, If you look down behind your oil fill port you should see an electrical connector sticking up, that is your FPR which is bolted into your CP3. It's about a 4-6hr job to change out depending on how everything comes apart for your. You should be able to get to the plug though.
 
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