I need big help here as my mechanic is clueless (and so am I). This problem has been going on for months now, no CEL or past codes.
-Here's my truck: '01 ram 1500 4x4 5-speed m/t
-Recent fixes: plugs, wires, cap, rotor, O2 sensor--Also had my computer 'reprogrammed' by dodge because there is a tech service bulletin for "cold engine acceleration hesitation" or something like that<--$100 spent for no reason.
-Things recently inspected by mechanic: Cat converter, plugs, fuel pressure, coil, TPS, maybe a few other things I can't remember. All were fine.

-My problem:
Cold engine-Rough idle (truck vibrates and sounds 'sluggish') w/ normal idle (~750rpm) but the needle on the tach jumps up/down by fifty rpms consistently.
Warm engine-After driving and coming to a stop truck idles at 500-600rpms and sounds very sluggish. Once in a blue moon my rpms will jump from 600 to 1200 rpms without touching the pedal when stopped + other times my gas pedal sticks for a few seconds after stepping off the pedal.

-Another major problem is 'rough' acceleration. Meaning when I'm pressing steady on the gas, the truck will accelerate normally for a while then all of a sudden start slowing down as if I took my foot off the gas (which I'm not) or lightly stepped on the brakes. During this slowing down, If I keep my foot on the gas the truck will buck/jump and I can hear a banging noise under the hood.
If I simply take my foot off the gas then step back on it, the truck will accelerate as normal until this happens again. This happens on a DAILY basis with the "episodes" occurring a lot on one day, then once or twice another, just randomly.

My mechanic suggests replacing the fuel pump with a new oem dodge one ($400+ part). But I'm not the one to throw new parts in just to see if it might fix the problem. He check out my fuel pressure and it was reading normal...but what about low fuel volume from the pump, could that cause my problems? I will ask him to check that before I wind up buying the pump.

I also think I might be losing oil fast since it's already below 'add' line and I've only driven ~2000mi since last change.
*I've looked into the throttle body w/ flashlight and it has no pooling oil when looking straight down. I have no small mirrors so can't check front or back of TB. I will take it off and clean it + check for oil as I know a bad plenum could cause some of these problems. (No oil leaks when I'm parked)

Any suggestions?
-Misadjusted TPS?
-Bad crankshaft sensor?
-Bad fuel pump?
-Bad O2 sensor?
-Bad compression?
I just don't know...And I'm sure my mechanic doesn't want to keep blindly inspecting my truck for free. -Thanks for any help

 

Check the TPS with an analog meter. Voltage should go from under one volt at idle, to better than 3.5 at wide open throttle. Meter movement should be smooth. If it is out of range at either end, or the needle jumps around as you open the throttle, replace the sensor.

Check out the plenum thread at the top of this forum. It is a standard problem with 2nd gen trucks, and I note that it isn't mentioned in your list. It will give you a fair few of your symptoms (oil consumption, erratic idle, various performance problems...) That needs to be checked FIRST.

If the plenum is indeed blown, and I am betting that it is..... need to fix that, change at least the plugs at the same time. O2 sensor replacement would be a good idea as well, and verify that the cat isn't clogged. (which it sounds like it is working on....)

You have a couple different problems going on there, and you are going to need to start addressing them one at time, till you fix 'em all.

Are we having fun yet?

Welcome to DF!

 

The cat might be clogged get that checked out

 

not to change the subject but has anyone ever had a miss fire in cylinder 5 i got to it was because i dont have a catelitc comverter but i put new plug wiranes plugs cap rotter bug changed throttle body changed injecters wat the hell and its got good compression in all cylinders can any one help me please

 

check the IAC sensor in the back of the throttle body also.

 

Your gonna want to start your own thread so that your issue can be attended to without taking away from others. Honest mistake by newbies.

 

The cat isn't clogged and the IAC was one of the parts that was already checked (i just forgot to mention that)...So those are fine.

I will take HeyYou's advice and check the TPS + Throttle body/plenum. I'm not too mechanically inclined (and I have no usable tools) so I have to wait until my friend who's a mechanic to help me out with that.

Thanks for the replies guys. I'll post my ending results later (if I can figure out what the hell is wrong).

 

I just changed the throttle position sensor. So far the rough idle was nearly fixed. It sits at about 625rpm but will intermitently move the needle up and down by 1rpm--probably the iac valves problem. And the engine sounds much better + no erratic jumping of the rpms at idle. It idles well at cold and warm engine temps. The truck accelerates much more powerfully and smoothly--only problem is that it STILL slows down by itself and now bucks/jerks more often. Maybe the computer just needs to adjust to the new tps? I doubt it that's it...so what would cause bucking + jerking?

 

Check the plenum gasket integrity in this manner:

Park on a slight incline, like a driveway. Let truck sit until cool. Take the throttle body completely off. Shine a light to the back of the intake manifold to the bottom back side. If you see any amount of liquid oil back there, replace the plenum gasket.

 

I don't have any updates yet. I'm having someone I know take out my injectors and inspect/test tomorrow or the next day so I'll post the results of that later. While I'm at it I'll ask him to take off the TB for cleaning/inspection as well (to check for plenum issues).

*I was wondering... Would a bad ignition coil cause this rough idle + bucking? Because my coil looks slightly damaged (top view):