2003 Dodge Diesel - Surges on Cruise

Going all the way back to mid 90's Dodge diesel's under cruise.

Here is where we discussed it before HERE

or a quick search will turn up forums like The Diesel Truck Resource

and The Cummins Forum both of which discuss it.

Good luck!

"cant see any visible leaks"

Leaking injectors leak into the cylinder and produce more or less power according to the amount of leakage.

You would not see anything unless you removed the injector and pressurized the system or you were inside the engine while it was running.

Dude! You spent all that money on a diesel, useless dually at that, chip, and not a $150 Dodge manual. Injectors (MPI) do not leak outside of the engine. A diesel engine runs best when it runs hard. Your cruisin in a dually! I would think it is bogged down, over fueling and not enough load for the horsepower. That goat wants to run or pull something. Don't get me wrong, I have a Dodge, too. Get educated about your truck before you go online!

I think many/most/all cruise controls operate with manifold vacuum. It's possible that you have a vacuum hose leak. I would just replace the associated tubing.

I had a similar problem once with a gas vehicle and it was a hose.

I have a 2004 Chevy Duramax with a simular problem. It only surges when pulling a grade and only between 30 and 45 mph. I got the same crap from the dealer you did.

I believe the real problem is in the cruise control and the fact that the dealer has no idea how to adjust it, or maybe its not ajustable. Because I can hold it steady manually. The mechanic took it for a drive and during the drive he discconected my chip and left it like that, told me it would be better now. (I guess he thought i had no use for the chip on there, pulling my 15,000lbs trailer ha ha)

I installed an aftermarket cruise control on a 88 Chevy Beretta and it did the same thing until I did a little adjusting

If you have a leaky injector, it should be at it's worst at idle, when the least amount of fuel is used. If you can pull the injectors, they can be checked at an injector or diesel shop. My guess is poor fuel mapping, but It is just my guess.

BTW Welcome to the insanity.

i got a 2oo3 dodge had this problem was pulling my hair out no one will believe the fix seems the clutches in the limited slip rear end were sticking causing the slack change the oil in the rear end problem stopped. take it for what it worth. Ernie