Cm870

[Rawze]

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If it is dying randomly, .. it does not matter that you tried 4 different ecm's... it could still be an ecm issue. Engines that run a bit and then stumble and die, is a typical symptom for an ecm that is going bad due to excess vibration or age, and it can be easily checked for. Just crank it up and then smack the ecm hard.. hard enough to almost dent its casing.. and see if it stumbles or dies. If it does then it is a bad ecm. CM870 and CM871 ecm's are notorious for this as they get old or suffer too much vibration due to some moron never replacing the crank shaft damper every 500k miles or so like they should have.

Matter of fact, I saw someone go thru 6 ecm's (they kept taking them from other trucks or buying them from repair shops or other online paces instead of directly from cummins), and engine still dies on them. It was not until they purchased an official OEM ecm from cummins that they got one that did not have this issue when they smacked the top of it.
here is a picture of roughly where to smack it...



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Ruling out the ecm for a moment...

Last resort is to monitor all the data inside the ecm with a proper screen file in calterm and determine what is controlling the fueling, engine mode control, etc., live while it acts up. Your description of it 'changing after 60-seconds' points strongly towards it changing engine operating modes improperly for one reason or another.. and it should not do this .. especially if it were actually properly de-mandated, hence the bad delete statements above. This (due to pi$$ poor garbage programming) could very well could be what is happening.

here is a screen shot of what to monitor to see what that ecm is actually doing ...
ref: http://rawze.com/forums/showthread.php?t...3#pid58693