Engine surges at idle

[PRY4SNO]

2002 Ram 2500 Cummins 4x4
305k km

I've searched but haven't come up with much in the way of solutions. The few threads with similar issues weren't what I've been experiencing. Hoping for some insight as to the root cause(s), or at least some spots to start diagnosing.

At idle the truck will randomly surge. It's done it while the engine is warm, or right after a cold start.

If left alone it would seemingly rev up to the limiter.

Give the pedal a quick tap and she drops down to idle quickly. In another few minutes it's surging again.

Would be interested in possible causes or places to start investigating.

Thanks!!

 

[PRY4SNO]

Bump!

Any ideas? Handy links?

 

[Chief USA]

Take a look here and see if any of these can help:

https://www.bluechipdiesel.com/troubleshooting-1

 

[PRY4SNO]

Thanks!! Nice to have somewhere to start. Quick read through has me thinking it's not the ECM (the 'Wait to Start' light doesn't come on while driving) but I'll see what I can find out.

 

[PRY4SNO]

Awesome, thanks. Nice to have a place to start digging in. Appreciate the link.