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My 2011 Sierra Denali LML's Cp4 recently grenaded and took my whole fuel system with it. Had all new injectors, filters and cp3 installed. The lines and tank flushed. Cp3 is an exergy sportsman by wehrli.

The truck is tuned with EFI Live by Kory Willis. I had all my tunes upgraded for the new conversion and pump by Kory. I had the guys at PPEI help me upload the new tunes to my auto cal.

So, after everything was installed and I flashed the new tunes all is not well. The truck seems to be defueling around 2000rpm. The rail pressure is around 21 Kpsi and injector rate timing is a bot +5. This happens at any speed. I can drive the truck if I baby it and even get it up to freeway speeds 70mph. However, if I try to give it any real power it will fall on its face every time at those above specs. The truck will shudder, shake and cut engine power until I let off of it. Very simmilar when the ABS / traction control will shut it down if the tires get loose.

Now, I've been working with the guys at PPEI and Wehrli to figure this out.They been doing me good trying to help figure this out. I have sent off a data log to Kory and waiting to hear back on that. So, while I wait I figure I would get some input from you guys. If anyone has had or heard of a problem like this I would appreciate your input. I'm trying to give my mechanic any help I can before he has to tear my truck back down again.

Also, my apologies if this isn't in the right discussion group.
 

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I'm having a similar situation did you ever find out what the problem was
 
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Its likely current to the regulator needs adjusting, very common on the 2015-2016 trucks with a CP3 conversion. They most always take extra time/data logs to get dialed in.
 

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Thanks for the reply I'm currently working with motor ops on this . Cameron said the same thing just hard to find a road for data logs. With speed involved.
 

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Thanks for the reply I'm currently working with motor ops on this . Cameron said the same thing just hard to find a road for data logs. With speed involved.
What ended up being the resolution to this issue?

We recently completed a CP3 conversion on a 2014 truck that was still running perfectly fine with the CP4. Now it does exactly what you described yours doing. Cranks and idles perfect, runs fine under very light load but anytime any load is applied/power demanded it will sputter, shake, and even cut off in some cases.

Fuel supply to the CP3 has been verified it holds a solid 10psi, watching data logs and the desired rail matches actual rail. I have checked over every plug and connection over and over. I have been back and forth with MotorOps, sent data logs, and videos but there seems to be no resolution
 

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I wound up getting good data logs to cam at motorops. It was tough for me to get them because I would run out of road . It turned out to be a regulator adjustment. Like [email protected] said. It's been good for like 15k miles so far.
 

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My desired and actual rail pressure did match when it was starving but I noticed they would both drop to 26-27 k then it would nose over at that moment and stop pulling. Now both stay at 29k. So it was commanding it through regulator voltage I believe.
 

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Did everyone get their stuff figured out??? I see this thread is a month old. I'm having what sounds like to be the exact same problem. Started out sputtering/hesitating at high rpm while trying to accel quickly...3/4 throttle to wot. Had my mechanic run datalogs and send them into motorops. Still waiting to hear back from that. But now it's doing the bogging down thing, falling on it's face when trying to accelerate at a decent rate. Fleece 10mm cp3 conversion and Fass Titanium 165. Truck ran great right after the delete (about a month ago), slowly got to this point.

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Anyone find out what actually was changed to correct this issue? Have a customers truck doing the same thing.


3 posts up....

I wound up getting good data logs to cam at motorops. It was tough for me to get them because I would run out of road . It turned out to be a regulator adjustment. Like [email protected] said. It's been good for like 15k miles so far.
 

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same here, below 50% throttle truck pulls hard anything over that and injection A goes to 3.0
 

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Anyone find out what actually was changed to correct this issue? Have a customers truck doing the same thing.
My situation ended up being a kinked fuel line. It was the return line underneath the air intake tube according to the diesel shop. I'd start checking all the fuel lines first. Could be as simple as that.

My truck ran good before and it was a slow fade to the light sputtering to completely bogging down and starving for fuel. So that told me it couldn't be the tuning since the tuning doesn't just change by itself.

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ANSWER FOR ALL YOUR QUESTIONS. I spoke with danville. They said this is a recurring issue on the LML platform with a cp3, and it cant be tuned to remedy this. They actually recommended i go to a cp4 stroker pump with the upgraded regulator that protects the motor. I also have a 2013 3500srw denali hd with this issue and i have the 10mm stroker cp3. I thought it was my sump. I was wrong. Im so frustrated, now i feel like i have to to buy another damn injection pump.

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And for the record, shame on lincoln diesel in wi. They could have been honest and told me, but instead just made the sale and played dumb. I found this portion out through a friend that goes there too, they told him because he was talking to them about my truck. American capitalism at its greatest.

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Its likely current to the regulator needs adjusting, very common on the 2015-2016 trucks with a CP3 conversion. They most always take extra time/data logs to get dialed in.
Hey Scott, How is the voltage to the CP3's regulator adjusted?

Is this done through tuning?

Thanks
 

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I figured out my problem, I had the feed and the return backwards.
 

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My 2011 Sierra Denali LML's Cp4 recently grenaded and took my whole fuel system with it. Had all new injectors, filters and cp3 installed. The lines and tank flushed. Cp3 is an exergy sportsman by wehrli.

The truck is tuned with EFI Live by Kory Willis. I had all my tunes upgraded for the new conversion and pump by Kory. I had the guys at PPEI help me upload the new tunes to my auto cal.

So, after everything was installed and I flashed the new tunes all is not well. The truck seems to be defueling around 2000rpm. The rail pressure is around 21 Kpsi and injector rate timing is a bot +5. This happens at any speed. I can drive the truck if I baby it and even get it up to freeway speeds 70mph. However, if I try to give it any real power it will fall on its face every time at those above specs. The truck will shudder, shake and cut engine power until I let off of it. Very simmilar when the ABS / traction control will shut it down if the tires get loose.

Now, I've been working with the guys at PPEI and Wehrli to figure this out.They been doing me good trying to help figure this out. I have sent off a data log to Kory and waiting to hear back on that. So, while I wait I figure I would get some input from you guys. If anyone has had or heard of a problem like this I would appreciate your input. I'm trying to give my mechanic any help I can before he has to tear my truck back down again.

Also, my apologies if this isn't in the right discussion group.
 
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