Randomly runs rough

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Apr 11, 2013 | 12:09 PM

TexasDiesel97

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From: Huntsville, Tx

Randomly runs rough

Took a 500 mile road trip the other day, ran fine the whole way up, almost made it home, and the truck started runninng rough at idle. Kinda like it was cutting out, step on the pedal a bit and bring the rpms up it would stop cutting out, but still run rough. Made it the last 50 miles home get in the driveway and then it runs like nothing was wrong. Pulled the codes and got the P0236 again (beging to think my MAP sensor is going bad). Wondering if the CPS might be the culprit for running rough? Any suggestions? Oh and I just put a new fuel filter in and cleaned the little screen before I left and learned when I got back it needed new batteries.

Apr 11, 2013 | 12:37 PM

blageurt

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From: Thornhill , Ontario

What happens when you unplug the MAP sensor ? Does it smooth out ? Also is there a chance that you have a bad UVC harness ? Last time my truck ran like that it was the IDM.....and it did not set a code either....

Apr 11, 2013 | 04:03 PM

Justin@DP-Tuner

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I do not think the MAP sensor is your problem. Have you checked the UVCH's?

Usually when a CPS goes south the truck will either not run at all or just randomly die every so often.

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Apr 11, 2013 | 05:41 PM

TexasDiesel97

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From: Huntsville, Tx

I unplugged the MAP sesor, it set the CEL but it still ran fine and still had plenty of power. Havent been able to pull the plug on the MAP while its running rough. I've had time to check the pins and plug on the passenger side back nothing seems to be wrong, plus there isn't a burnt smell. Hope to have time to night to check the driver's side.

Apr 11, 2013 | 06:20 PM

blageurt

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From: Thornhill , Ontario

Forget about pulling the MAP plug......it is looking more like a UVC issue or a connection involving the Injection system ...Are you able to read Live Data ? How about a contribiution Test ?

Apr 17, 2013 | 10:12 AM

TexasDiesel97

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From: Huntsville, Tx

Sorry guys it's been pretty busy lately. I have learned that I need a new alternator (voltage stays low after start up for a minuet or so then picks up) I'll be picking up a new one today, after that I'll check to make sure the new batteries are still good and hot. I have a scan gauge, so the only data I can see is what it will show, but if I remember it can run a cylinder contribution test. I'll figure out how to do that and see what it tells me.