I have a 2001 6 speed and over Christmas my ECM went out. The pick up ran well for 300 miles and then died on me again. Only this time it would start back up and run for exactly 26.2 seconds and die like the key got turned off. The mechanic went through every ground and connection in the truck and everything looked good so we warrantied the ECM and he figured my edge comp took the ECMs out. The truck runs well now with the new ECM but my tach will bobble a few RPMs when cruising down the road, the motor does not run rough or anything but the RPM gauge is fluctuating. Could this be the signs of a fuel issue? or something else entirely? I have a Brand new fass DDRP everything else is stock. It is a VIN 7 so it has a cam crank position sensor. Only one no crank sensor by the starter.

 

okay. to be clear is just the needle moving or are you feeling the power change as the needle moves?
Does this happen when you use Cruise Control?
since you said Mechanic I would assume he tried to pull codes? are there any codes. my first thought would be early sign of your APPS showing age and starting to go and you dont always have a code on an APPS that is still working but just not 100% effecient when at certain speeds.

does this happen around the same speed? or can you see this at 20mph and 65mph etc. You can always do a APPS reset. That is easy and you can do yourself. search on here or google for APPS reset.

also you didn't say but did you completely unhook the edge and return to stock and see if that was causing issue. Edge's are known to cause many gremlin's with the 24Valve cummins. So did the Mechanic say how the Edge took out the ECM?? odd...

my 02 does this at Idle will move up and down roughly 20 rpms when cold or warm. This has always done this on my truck since I have owned it and put in big injectors. This is normal from what I have read on my truck.

post your answers and let the forum see what they can help with. if you do have some codes or any Troubleshooting questions steps etc. I find this site and guy really good at what he has posted. I have used this many times. latest was last year when i troubleshooted and found I had a bad ECM.

Welcome To Mopar1973Man.Com

go to article data base and then 2nd gen 24valve and then go from there depending on what and where you want to search.

 

I do not feel it in power or in the pedal it seems to be in the needle. It happens around 1700 RPMs through 2000. It does not do it at an idle it starts at 1700 RPM. It is way worse using cruise control. I completely unhooked the Edge it's all the way out on my work bench. Besides a ats 3000 turbo the truck is completely stock. And no codes at all. Maybe I am just being paranoid but my truck has been down for a month so I really want to keep it going. When the ECM went out I had several shops want to trow a lift pump, injection pump you name it at it. But this mechanic spent the time to properly diagnose it. He didn't say exactly how the chip took out the ECM. He just thought that since I have went through two mopar ECM's in the last month and all of my wiring and grounds are good the chip had to be what was taking them out.