I just picked up a 94 2500 4x4 CTD with automatic tranny. On the freeway, I notice that sometimes it revs up about 150-200 RPMs for a couple of seconds and then drops back down (this is at a constant speed). The truck has 222k on it, the tranny was rebuilt about 40k ago. Also, around 55mph, it doesn't want to go into overdrive or will shift into and out of overdrive. The shifts seems firm. (I am new to the 12v & 2nd gen).

Any thoughts?

Thanks,
Nick

 

Sounds like the TPS (throttle position sensor). Alot of reading here using the search feature. You can read about cleaning and replacing as well as pictures depicting exactly where it is located. I was able to limp along with mine for a year or so by spraying electrical contact cleaner from the outside. Ended up replacing it a few months ago. I believe it was around $150 from rockauto.com. You can buy them at NAPA, etc just make sure they don't try to selll you one for around $60. That is the one for the gas powered Rams.

Take care
Steve

 

You may want to do some maintainance 1st , flush , adjust bands , maybe even rase the pressure adjustment [ needed with this combination ] , then look for problems , I found that when I bought mine [ small ind, dealer ] so not much history , at 209,000 , on the way more I had some of the same same issues , so I check & found that the brake sw. & peddle wear too close , hit a bump & out of OD , lock up & cruse , so I hot glued a small washer on the foot of the sw. , good for over 2 yrs. now .

 

I'll search on that TPS. Thanks.

How much would a shop charge to adjust the bands? I was thinking about taking it to a Cummins dealer and have them check it out thoroughly. I

am wanting to bomb it a little, how much will the tranny hold? I was thinking gauges, 4" exhaust, 3k gsk, and then maybe fuel plate and timing.

 

Also check the trans temp sensor.

 

If you get wild with pushing the plate and AFC housing ahead then you are going to run into problems with the stock TC... Though for mild bombs like that a shift kit and billet single disc TC would be more than enough to keep things happy and can be had for a little more than half the price of a billet triple disc... PM me for details if you would like.

The TPS, safety switch on brake pedal, and trans temp sensor are all good places to look for problems judging by what issues you are having...

 

I will check the TPS first, I searched and there are a lot of threads on it.

Another question, the light to indicate which gear you are in is out in all selections. Is it just a bulb or is it something else? Thanks

 

Unless you somehow managed to an option that my truck does not have... It should be an orange peg that is moved up and down as an indicator by linkage in the steering column. I may have broken and fallen down into the dash or on the floor earlier in it's lifetime.

 

I thought it was a peg, but figured since it was out it might be a bulb. Its not a big deal. Thanks.

 

My truck did the same thing when I bought it. It was the TPS. I elongated the holes and adjusted it 30k ago and it still works great.

 

I'll test it and clean it first, but if I need to get a new one, who has them at the best price? I called autozone and they don't have one listed for a 94 and the one for the 95 is $215ish if its even the same part.

Hammily, when do we get to see pics of the 12v Excursion?

 

Check the brake light swicht had same problem with my 96'. Changed the switch for $18 good as new.

 

Can you give a little more detail on where this is? Also, it doesn't shut the cruise off when it does it, and it does it even if the cruise isn't on, not sure if that helps or not.

Thanks

 

For TPS go here http://www.rockauto.com. In the catalog you can find it in the Emissions category for some reason. Listed price is $151.89. I think you can get a 5% discount by entering "turbodiesel" or something like that on checkout. Others may chime in on the coupon code. You can also get the brake light switch here, listed as Stoplight switch

Take care
Steve