SIXSLUG

For the past two weeks I have been experiencing a very slight surge up to 5th gear speeds that is too small to register on the tach.

6th gear it seems to be non existent. It is erratic and does it more noticably when cold but will also occur at 190F operating temperature.

Any ideas?

6spd05Dually

Do you have this problem when you first start the truck also? Mine surges then smooths out after a few minutes. You might want to check with cummins about a flash update. Dodge put out a TSB bulletin about this awhile back.

Since your engine is prior to 2003 before Dodge put their own ECM that Cummins can't communicate with their software, you can go into any Cummins repair center and they can plug into the ECM. Hope this helps you!

SIXSLUG

I can also feel it a highway speeds between 50 and 60 MPH, after its warmed up.

I have good fuel pressure and run Power Service, 3 white bottle/1 silver bottle routinely over 4 fill ups.

I got a new ECM about three years ago when the original gave it up. Not sure if that tsb includes my year.

6spd05Dually

I only had this surge when running cruise control going downhill. I have no clue why the engine does this, but I thought something was wrong, but it does the same thing everytime on a downgrade. The speed didn't matter in my case.

My bad! The tsb was for 2003-2007. Is your ecm you put on there have 3 port hookups or just two? Let me know.

SIXSLUG

I'm not sure about the ecm, it was done under warranty.

I'm close to switching injectors and running an airdog fuel system so I'll see if that changes anything.

6spd05Dually

The ecm is located on the driver side of the engine if you don't know the location. You should either have two large ports with a small port if it's the ecm industrial one. Two big ports would be the one chrysler put on and pushed Cummins out of the way on in 2003. Your ecm should have 3.

If I were you, I would take the truck in and spend an hour labor on diagnostic and let them tell you first. It could be a simple inexpensive fix instead of pouring out all that money on the airdog IMHO. Your truck though so keep me posted.

Homestead

Does the surge go away when your using cruise?

On the manual trucks, the cruise is electronic so when on cruise you take the APPS out of the equation.

I had a similar experience and the surge progressively got worse as time went on. Same as yours, was barely noticeable certain speeds and certain gears but entirely went away when cruise was engaged and the truck ran perfectly.

Ended up being the APPS was the cause.

Something to check.

Jeff

SIXSLUG

Thanks guys, the apps is a possible. It does not do it with cruise engaged.

The airdog and injectors are a treat for paying it off! I just wanted to finally upgrade the fuel system and get a little more economy and power out of it now that she's broke in!

My trucks an 01 HO so would my ecm still have 3 ports total, or 2 and 1 small, 6SPDuallyTX?

01RAMer

If you would, permit me to be dumb. What is APPS?

RowJ

Newer name for the TPS or throttle position sensor! Stands for Accelerator Pedal Position Sensor
Read HERE

RJ

01RAMer

Thank for the info, RowJ.

6spd05Dually

Row Row, this makes sense due to the fact that if you remove the battery cables on both batteries and leave them off for an extended amount of time, you can re-learn the ecm and driving habits. For the people who will call me bs, here is living proof. I used to get 18.5 to 19.5 mpg with miles being over 150K. Over time, I avoided going the speed limit, stayed off the highway when I could, and kept the rpm around 1500 when possible. This took time, but now I get 21-22mpg. These engines aren't not designed to hot rod, but to stay at a lower rpm and go long distances.

SIXSLUG

Update: APPS reset cured surging/hesitation. She runs a lot smoother and has a different sound on the highway. Smoother.

I also cleaned and checked the IAT sensor and cleaned the MAP sensor.

Thanks for all the help guys! I'm betting I will see a slight gain in mpg also!

SIXSLUG

Sooooo, over the past week I have noticed a couple things since cleaning the IAT and resetting the APPS:

Easier/smoother starts

Smoother running thru out entire acceleration period.

Hand calc'd +1.78 mile per gallon over 15 gallons of fuel. Sort of inaccurate since I fill it up the neck as far as possible and wasn't at the same bay at the fuel dock so could have been out of level a tad.

Either way this was a simple maintenance item that I think I will incorporate as at least a once a year event from now on.

Again, Thanks for all the advice and suggestions.

Bandit99

What is the IAT and where is it?