Ok so i just recently joined the cummins family and picked up a 2001 Ram 2500 that I fell in love with instantly. Now I have had it for a month and I am having an issue. I drove about an hour and a half from my house and it seemed like the truck was losing power all of a sudden. The rpm needle was kind of bouncing a few millimeters. It is especially happening going up hills. The shifting kind of seems different too, don't know if it is a related problem but it will sit at like 2300 rpm before the last shift at like 50mph. The problem is spuratic. Like I said it did it there, and then I got back home turned off the truck and it was fine the next day. Just got back from a 10 hour trip and it was fine up till the last hour to hour and a half both there and back. I changed the lift pump before returning home. It is an automatic. My mpg goes down from about 18 to 10 when the problem acts up. Could it be an electric problem somewhere since it goes away after being off for a bit? It doesn't have any issues driving around town it just happens on these long highway trips. Please HELP! if you need more details let me know

 

Welcome to the world of Cummins and DF!!

How old are the batteries? The bouncing tach could be a symptom of a bad crank position sensor. Any codes at all? OD lockup around 50mph sounds about normal, that when my 07 locks and drops the rpm's down to ~1700.

 

I'm not positive how old the batteries are because I just got the truck but they don't really look to be too old, and the terminals look good. It's not throwing any codes which is really throwing me off. Also when it starts to do it, if i hit the accelerator hard it will rev up but the truck won't accelerate at all.

 

since its a 2nd gen 24v, get a fuel pressure gauge on there ASAP!

if while running that gauge shows anything above 20psi or below 10psi, replace the lift pump with a GOOD aftermarket lift pump like airdog, fass, or raptor rated at 100GPH or higher. stock lift pumps on these trucks are junk and can't keep up with stock fuel demand.

the vp44 injection pump is very sensitive to fuel pressure and it can die quickly from having too much or too little fuel pressure.

my pressure sits at 17psi idle, 16psi cruising, and 15psi wide open throttle with the fueling box set to kill...

regardless of what the problem is, get a fp guage with snubber/needle valve on there ASAP!

you can check the codes on your truck to see if you have any trouble codes that might shed some light on the issue. with the truck shut off, cycle the ignition off to on 3 times quickly and leave it on the 3rd time but do not start it. the error codes will display on the odometer readout and will say --done-- after its done displaying all of the codes.

 

Thanks Jigabop for the code advice, I tried that but it came up with no codes. I am going to buy a fuel pressure gauge and the lift pump I got is just a temporary thing till I can get an Airdog. I am going to look over all the U-joints tomorrow because I'm thinking it might be that because of all the shaking that I am getting. It also seems to progress. It will start it all of a sudden at highway speeds then progressively get worse till the truck is struggling to go 40. And like I said I will hit the accelerator and it will rev but not speed up. I really hope it is not a tranny problem!!!

 

wait you didn't say anything about shaking in your first post? Shaking is usually a tire or more than one tire out of balance. As for rev and not speed up, sounds like possible torque converter issues. check and make sure your trans is full of fluid. if its right at the full line, add an extra quart on top of it. dodge transmissions like running at least 1qt overfull. (it takes ATF +4 synthetic in the 47re) that might get you by for a bit. If you do have a converter going bad, you will probably want to do an aftermarket single or triple disc converter and a valve body to beef up the trans a little bit. those however are mild mods so don't expect it to hold up to tons of hp/tq if you decide to build lots of power out of your truck..would need a fully built billet transmission for that.

anyway I would first go to a tire shop and get those tires balanced and ask them how far they were out of whack. you can check u-joints as well, but that wont cause a vibration or shake unless the drive line is about to fall out, in which case it just wont drive. usually when U-joints go they start clicking..

for tire shops: check the brand on your tires and go to a shop that sells that brand..they will usually balance their own tires for free..

 

yeah sorry there are a lot of symptoms so it was hard to remember them all. I don't really think it is the tire being out of balance because like I said, when it starts it gets progressively worse until the truck is struggling to maintain 40 miles per hour. Then I leave it overnight and it is fine again. Some people said the tranny might be overheating but it doesn't throw a temp error. And then some people said valves in the tranny may be sticking. When I say shaking it is almost more like a load is suddenly being put on the truck I guess is the only way to describe it, and like I said the mpg goes way down when it happens

 

hmm converter or lockout might be acting up...

 

Yeah I would say that would affect the tach like I have described. I guess I will have to take a look at that stuff. But I have heard that if it was a torque converter then it would be through all the gears and wouldn't be so spuratic, is that true?

 

honestly your best bet is to go on cumminsforum.com and post in the 2nd gen 98.5-02 powertrain section and have one of the guys with an automatic answer that for you.

I've only owned 2 automatics in my life, 1 was a 86 chevy 1/2 ton, the other was a 2002 jetta tdi...all the rest of my vehicles have been manuals so I don't have much experience with automatics...

btw: have you checked your fluid levels yet?