Howdy guys. Before I start I would like to say that this is my first time owning a Dodge and know very little about them so bear with me lol. It's a 98 4x4 with 360 magnum. I just got the front end drivably fixed so now I'm turning my sights on the engine. The first thing it does is it randomly will stall at idle, and I really mean randomly sometimes its when its cold other times its when I come up to a stop sign after driving for 20-30 miles. It does however start right back up after it stalls although sometimes it requires a little gas, and have to keep my foot on the gas or it will stall. Then sometimes by the next time I stop its fine again be it a mile or 50 miles. Now, once I'm moving it sometimes (relatively often) will bog when even slowly accelerating, if I floor it, it usually clears up. It also seems to lose power while cruising at a constant speed, Its pretty slight but you can feel it lose the power and slow down a bit then pick back up (Does it while accelerating as well) when it loses the power I noticed that it is sometimes accompanied by a backfire. Ok guys one more thing, and this is the only not random thing that happens all the time at a constant. If I try to hold the truck between 45-55 mph and just cruise the thing bucks and shudders, if I give it enough gas to downshift and bring up the rpms it goes away, if I let off the gas it goes away. It feels weirdly like driving a manual in 5th gear at 5 mph (just an illustration lol) It just feels like the engine is stuttering and having a hard time keeping me going. (60-70 mph is just fine as is under 45) If I put it down, the old girl proves that she has plenty of power so I just dont know. Ok I'm done with my novel for now guys, Just wanted to put it all out there in case its all related. Thank everybody in advance for any help that can be offered!

 

sounds like a misfire - a bad spark plug, or wire, or distributor cap, or rotor. if you haven't replaced all that, do so.

welcome to df.

 

On a Mopar I always replace the crank sensor with dying/runability problems. Also check your IAC valve and TPS.

 

Mine was doing the same thing.

Is your truck chipped? Check your PCM plug on the passenger side of the firewall. Should be a box covering the 3 plugs. Check the plug closest to the drivers side. I took my chip off and now mine works fine.

If that isnt it then I would start cheap. Coil, then id try crank sensor. Order the one from rock auto. Its cheaper and ACTUALLY WORKS.


Semper Fi.

 

I had the same thing happen to me. Took me a while to track it down. Ended up being an injector trying to go bad. It would bog down and misfire randomly. It took several months before I finally found it. The only reason I found it was because it finally went completely out and was doing it all the time which allowed me to find it running a simple test this simple test.

Try letting the motor run at idle and unplug each injector one at a time and listen to the engine for change. (Don't forget to plug it back in before moving to the next cylinder). You should hear change in the way the motor is running while the injector is unplugged if all is right. If you unplug an injector and hear no change, then you have found your problem. You can run the same test on your spark plugs.

It could be a number of things causing your problem. Fuel pressure/delivery problems, failing plugs/wires/cap/rotor/coil, CPS,etc. There is probably more that could cause it but that is where I would start.

 

I have a similar problem with a 2001 B1500 van, 3.9L six with 118,000 miles. Only seems to be low speed. Slow down like to go around a corner, sit and idle too long, or just go slow.
All the power goes away, engine lugs and backfires, vehicle barely moves. Turn off the ignition and starts up right away. Drive a little way, repeat, over and over.
Have replaced cap and rotor, no change. Coded the PCM and have PO443, Evaporative Emission Purge Control Valve Circuit. No one I have spoken too will admit that a purge control valve malfunction would cause those symptoms.
My mechanic wants $65 to recode and check the circuit, and $135 to replace the valve if it is bad. But he doesn't think that's the problem either.
All this started with an alternator freeze up on the interstate which blew the serpentine belt to bits.
Symptoms started as I drove away from that repair. Anybody have clue?

 

Unplug front O2 sensor, and try again. See if that helps.