Still looking for any ideas. I have a 2001 Dodge Ram 1500 Quad-Cab Sport, 4x4 with a 5.2L 318 Engine. I have about 81,000 Miles on it. About 2 months ago I got a code for a ECT Sensor. I replaced the sensor and changed the oil, oil filter, transmission fluid, transmission filter, transmission gasket, front and rear axle fluids. I drove it for a little and immediately recieved a code for a GROSS EVAP LEAK. I replaced a few hoses and could not find it. I took it to the shop last week and they smoked the engine and found a 4-5 inch leak in the hose going into the charcoal canister. They replaced the hose and that fixed the issue of the code and the idling to a stall. During this period when I would leave the truck overnight and wake up at 5AM to go to work I would start to go up a hill about 1/4 mile from my house that would cause the trucks RPM's to get into the 3000's...this would start a violent bucking/lunging. The truck would shift gears and the RPM's would drop into 1500-2000. After the truck would warm up (a mile or two) the problem would not occur. I would find another incline that would cause the RPM's to get into the 3000's (Roughly 3400) and the problem would not occur. I leave the truck sit at work for about 12 hours and start it up and have the same problem. I get home and I would leave the truck overnight and I would have the same issue in the AM. I am completely lost as to what this may be. A temperature sensor? Transmission? Just to let you know it runs fine all the other times and there are currently no codes showing. Please let me know any and all suggestions. Thank you in advance for your time.

The truck got to about 3000 RPM's and felt like it would not go and then it jumped to 4500 RPM's then back down to 2700 RPM's and then back to about 3800 RPM's... I immediately took my foot off the accelerator and they RPM's stabilized. I took it to a very steep incline and got the RPM's up and had no problems and the tranny shifted fine. I hope this may help direct us to the problem. Bad plugs? Wires? I have no idea. It almost feels like something is miss firing....


Thanks,

Bryan

 

if somethings misfiring you should be throwing a code. I have no idea whats happening to your truck but i would have done the same things you did. did you check out all the gears in the diffs? any f'd up teeth? Did you check your transfer case fluid?

I had a problem with a surging engine too... mine was the iac motor. My truck surged so bad that at one point when i had bald tires and it was raining , while i was on the highway doing about 70 my tires would actually spin when it surged. I then checked the tps, map, and iac at the same time. I noticed that my wiring harness for the iac was loose, so i tightened it. I then cleaned the iac, map and tps off with some throttle body cleaner. Never had a problem again.