So, this problem has started recently. This was about seven months after I solved an issue with my TPS, stemming from the TCM being broken that caused surging and stalling. Recently, my truck has been experiencing vibrations and slight RPM fluctuations while sitting in drive and at idle. These fluctuations occur at a steady interval, but they have recently coincided with the truck behaving like it is choking a bit. My battery was replaced after the truck didn't crank and my grandpa and I gave it a jump to get a new battery at O'Reilly's. This solved the problem for a bit, but now it's still continuing whether the truck is cold or warm. I'm under the impression that it may be my torque converter, given that the vibration seems to occur mainly to the right of where my foot is on the brake. Another thing that has occurred only twice was the RPM refusing to boost while on the accelerator, with one of the two occurrences being that the RPM wildly fluctuated between 250-500 before finally settling and allowing the truck to accelerate. Just a few days ago, I had a moment where I was going to hit the gas, but when it did there was a brief moment where I could hear the throttle opening, but no acceleration until that brief second was over and the accelerator properly engaged when down. The A/C seems to have an effect as well, sapping out enough energy to where it seems to trigger it too. There were no audible vacuum leaks. I'm scratching my head, does anybody have a plausible explanation? I need this truck for school. I can't tell whether it's an IAC issue, spark plugs, transmission, or anything else. The vibration occurs while moving as well, around 30-45 MPH or 55 MPH.

 

Cylinder misfiring?? How old are the plugs/wires/cap/rotor?

 

That's a possibility, but I have little to go off of. My dad bought this truck a year or two ago and there are 117K miles on it. My dad said that he has changed the spark plugs, but possibly not the wires. The starter and alternator were okay, according to a Tesla meter. The cap and rotor haven't been checked as far as I know, so they may be a cause. I'm assuming you mean the distributor cap.

 

Correct.

Think I would dig in there, and at least see what they look like on the inside. Mine on my 96 Ram was carboned up pretty bad. It would run decent, but, random misfires at idle, and don't even think about going past 3/4 throttle.......

 

I only hit the gas when I have to speed up, or when I'm going up a hill and need to go faster. I'll try checking the cap and rotor.