truck cutting out and missing at idle!!

**montoyacummins** · 08-31-2010, 05:25 PM

Hey,

My truck has had a little miss for about a year, but lately it has became worse, i usually run with my chip off and today i turned it on i placed it on the 9th setting and at wot my truck bucks and cuts out, and an excesive amount of black smoke comes out. more than usual, you notice this problem on the three highest settings. my lift pump psi never drops below 14 and i recently replaced the apps. so i dunno whats going on. oh and it takes my truck a little longer to start like a hesitation in cold or hot weather. it also smokes like a bluish color when i first start it and sometimes white too.. could it be injectors? my vp is has about 50,000 on it and the Lp never dropped below 14 psi.

what could be causing this guys, i need your input

thanks Andres

Steveo24 · 08-31-2010, 05:32 PM

Have you checked codes at all? SOme Map sensor codes can set and not trigger the MIL.

**montoyacummins** · 08-31-2010, 05:36 PM

ya i have not recieved codes, it has a new map sensor too

Steveo24 · 08-31-2010, 05:44 PM

Remember just cause the sensor has been replaced doesnt mean that the ECM is seeing the right boost levels. There might be a wiring issue etc... It really will be a crap shoot if you don't eliminate the fact there are no codes stored.

**montoyacummins** · 08-31-2010, 05:48 PM

i will run it again but last i checked everything was fine to me it seems more of a fuel issue my truck is getting bad millage now. i know the computer works because it threw codes about a few weeks ago but it was nothing to deal with this just the batteries.

**montoyacummins** · 08-31-2010, 05:50 PM

the truck has never had injectors replaced the millage is at 212xxx

Steveo24 · 08-31-2010, 05:52 PM

does it idle like it has a dead miss, or does it idle smooth??

**montoyacummins** · 08-31-2010, 09:47 PM

it idles like it has a dead miss it dont idle smooth the RPM gage moves around about at most 200 it fluctuates up and down. and when you stand by the exhaust you can hear the miss almost like on a gas car.

Steveo24 · 09-01-2010, 08:36 AM

I wold try a heat gun at the exhaust manifold at the outlet of every cylinder t see which one is cooler than the rest. Then when I fouond that, I would probably pull an injector and try another one.

ag cummins · 09-01-2010, 09:25 AM

I had the same symptoms for over a year. No codes, tried every thing I could think of, sensors, connections, grounds. I refused to believe it was my fairly new VP. I wanted to upgrade injectors and get away from the jammers I was running anyway. Got a set of jkidds matched injectors. Problem solved.
But that was my truck. You could have other issues. If in doubt and you don;t have the funds, you could pull the injectors and take them to a diesel shop and get them pop tested. May ease your mind and eliminate another piece of the troubleshooting headache

**montoyacummins** · 09-01-2010, 04:01 PM

ok so my truck ended up throwing a code well two a P0251 and a p1693.

ag cummins · 09-01-2010, 04:35 PM

The 1693 is a companion code, but the 0251 I believe is a fuel circuit prob in the VP.