Cummins ISM not reading boost correctly?

[Magard]

I don't have first hand knowledge but I have read here sometimes air can get into the radiator from the turbo. It has coolant lines to it so somehow I guess it can get boost pressure in radiator. Another thing that I would suspect is turbo speed sensor. If the sensor isn't reading correctly it could make it defuel trying to slow down turbo. I know you said you have a new turbo but that doesn't seem to mean much. I just had a bad speed sensor on what I believe to be a new turbo on a cummins reman. Just throwing that out there I'm pretty new to all this emission stuff someone else can help verify that theory.

[Mikesuburban1]

I did a combustion leak test today and everything seemed good. Im still waiting on my buddy to come with his insite so we can read the sensors. I also noticed im using more fuel and the last time it was like that the egr valve was stuck open but i took one end on the cooler off and it opens and close so i dont think its that. Im just baffled the truck ran so good it was pulling like a freight train and out of knowheres it gives me problems again

[in2trux]

I would get a pressure gauge on the surge tank to see what psi it's running at.
Loss of pressure or combustion intrusion could be causing in to run hotter.
Leaking headgasket could be pushing enough coolant into exhaust side of egr, coolor, that could explain excess moisture at delta p.

[Mikesuburban1]

So we hooked insite up to the truck and no codes so now im really getting frustrated. Ran egr and turbo test and both passed did cylinder cutout and everything was good . One thing i noticed is the suction line from the tank rubbed on the frame and took a good chunk out but no fuel leaking but could there be a pin hole in the line like microscopic but just enough to suck air? And if it was sucking air would it run crappy? Hard start? Also can anyone on here look up what my calibration should be? Right now its 06060011 my esn is 35179619

[Magard]

Have you tried a different map sensor. Seems like your manual gauge is tell on the map sensor. Even if it's new doesn't mean much. It might be functioning good enough to not throw a code but not showing full boost. I would say a map sensor hardly ever throws a code unless it is broken. The computer probably blames something else for its faulty information.

[Mikesuburban1]

(02-28-2017 )Magard Wrote:  Have you tried a different map sensor. Seems like your manual gauge is tell on the map sensor. Even if it's new doesn't mean much. It might be functioning good enough to not throw a code but not showing full boost. I would say a map sensor hardly ever throws a code unless it is broken. The computer probably blames something else for its faulty information.

I changed the manifold pressure sensor and no diffrence. I remembered there is a small brass screen filter in the top of the fuel pump, i took it out and it was pretty black so im gonna see if i can get a new one tomorrow along with some new fuel line

[Mikesuburban1]

Well i think i fixed my power problem. Changed the little filter on top of the fuel pump and changed the suction line and my truck pulls again! Thanks everyone for all the advice!