I have a 94 Ram 5.2 w/25,000 miles on it. The engine is rebuilt, there is no cat on it, all the sensors have been replaced. Besides the sensors on or around the throttle body. It has a new fuel pump, the injectors have been removed and cleaned, new egr valve, new spark plugs and wires, cap and rotor, and new coil. My problem is when it is running , idling or going down the road, the engine seems to be pulsating. It runs good then poor, so on and so on. Like it's getting fuel and then not getting fuel. It also does it under acceleration. Sometimes I'll crank it up give it the gas and it wants to die, but it burps or backfires thru the throttlebody, then clears up. But it stills surges all the time. The surges are faint most people who ride with me can't feel it. I need some advice here and don't tell me I should just go buy a Chevy. I've got too much money invested in this truck.

Did you change the fuel filter? Might be worth checking out. Also, My '01 Ram 5.2 had a rpm surge issue at idle, dealer said it was the idle air control motor. I had them clean the throttle body - and that problem disappeared without changing the iac motor. You also might try resetting the computer by unhooking the negative terminal on the battery for an hour with the key in the "run" position.

Might be the throttle position sensor. Maybe.

What transmission? Something slipping?

Might be the throttle position sensor. Maybe.

What transmission? Something slipping?
I have a 46 RH that has been rebuilt by AAMCO.

I have a 46 RH that has been rebuilt by AAMCO.
The transmission has 20,000 miles, and hasn't gave me any trouble since AAMCO has fixed it.