Detroit 12.7 DDEC 4 Interesting problem

I’m have the same problem with my truck

 

I’m having the same problem with my truck I have same truck same spec did you find out what was the problem

 

I don't think he's here anymore this thread is over 3 years old. I deff don't think it was running lean like he said or his egt would be way up not down like it was

 

If boost is low, there's likely a boost leak. Most shops will just pressure test the CAC like idiots but most leaks come from the piping. You need to pressure test from the inlet on the turbo to the intake on the engine.

If the manual boost gauge is reading different then the computer one then odds are the boost sensor needs replacing.

Only other thing that would be causing low boost and power is a weak fuel pump or bad injectors . On my c15 I had low boost and chased it forever, we pressure tested the fuel pump 5x and it passed. Finally one shop pulled it off and found it had no vacuum on the pump and would test good at idle but would fail under load on the dyno.

 

I drove a 430-470 that acted like that when the manifold pressure sensor got sooted up. Pull it out and clean it, only takes a few minutes. If nothing else it’s one more possible eliminated.

 

Sounds like ur not getting enough air to the bigger turbo? If it's a manifold leaking take a acetelyne torch and run pure oxygen around the head and intake lines at idle it will speed up idle if u find the leak? But u put a bigger turbo than factory the lines and breather were speced for the garret with wastegate...

 

I'm having the same problem right now but I'm leaning more towards the boost sensor that's located on the intake manifol I just took mine out this morning and It looks like it gave up i see a lot of moisture build up and the o ring was wet like blow by maybe but my truck sputters like it have no boost at all maybe some one can help me to

 

Reviving this from the dead, anyone ever pinpoint this issue?

 

I have similar issue, too bad the Original Poster did not do update on the problem. After I read the whole tread I think his problem was in the ECM settings. I am thinking of sending my ECM to some good detroit tuner to check it.

 

@periodic

 

Yeah, mines having the same issue. Seems like nobody has figured it out haha.