Surging/loping
 

I own a 1996 Dodge Ram 2500HD with the Cummins TD and 47RE auto trans. I have been experiencing a wierd problem on ocassion. I'll start the engine and all goes well, but when I put the truck in drive or reverse, it surges or lopes. It only happens on first starts of the day when the engine is cold and does not happen often. The nearest thing I can relate it too is a gas burning car when the choke sticks closed and the engine runs way too rich and surges or lopes. My truck only does it for a few minutes and only when under a load (idling in gear), no load (out of gear) it idles just fine. Anyone experience this before?
Mike

How many miles are on the truck? Is it stock? What's been done to it?

It's a pretty far out possibility, but it could be the first signs of the governor assembly in the injector pump starting to go. If that's the case, the bad part is that benching an IP is costly. The good part is that you probably have thousands of miles of driving before it becomes so bad you can't deal with it anymore. It may be something else entirely, something simple and easy and cheap or even free. This is just the first thing that popped into my head, I'm sure someone else will chime in with other ideas.

Sounds like your Idle is too low ..

900 @ idle .. 850 ish in gear .. I have mine set in summer 925 ish .. never have to adjust mine in winter .. although I do let it warm up a bit though .. or pulg it in .. :tu:

Just came back from the test drive after replacing the Overflow valve and the Prefilter. So far I am very impressed, but I only went about 2 miles. After it sits all night and I fire it up cold will be the real test. The whole job went pretty smoothly. The only problem I ran into was trying to keep the new gasket on the Prefilter bowl in place, but a little rubber cement took care of it. Did find the heater bolt loose. I jumped on the throttle and released it immediately several times and it did not stall this time. Throttle response seems to be better, too. Will keep you posted. Thanks for all the help,
Mike

I can bump the key when the Engine is cold ( 50*) and it will fire right off no prob ... haze is normal ..:c:

Spoke too soon!!

It really gets bad when it is cold and the engine is just started, If I give it the slightest bit of throttle or take it out of gear, it smooths right out.

what are you rpm's in D ? :humm:

Assuming the second line off 0 is 750 rpm, it is a hair under 750. I also guess that if I adjust the idle speed up, the TPS will need to be readjusted, correct?

It shouldn't, no. And you should definitely raise it a bit.

the second line is 500 .. the third is 750, then 1K ... you need to be between the 750 and below the 1K in gear :tu: