My Dad has a 2000 Dodge Ram 1500 with 5.2 Liter engine, automatic trans. The engine will surge unexpectedly without warning. It will fluctuates up 200-300 RPM whether he is driving, stopped in park or in gear. It doesn't seem to matter what you are doing when it is affected. It will return to normal on its own after about one second and will vary on the number of times that it will do this. There is no ryme nor reason.

He has replaced: MAP sensor, plugs, plug wires, distibutor cap, rotor.
Any suggestions for repair would be appreciated.
Thanks,
Dave

 

si the CEL on?

not sure.. but i would wonder if the torque converter is locking and unlocking..

 

how could we check this? do we need any special tools? No lights are coming on. The surge affects whether the vehicle whether it is in gear (stopped or driving at highway speeds) or in park. Would the torque converter lock/unlock be still affecting it?
Thanks

 

not sure how you check it.. theres wires going into the tranny that tell the TQC to lock and unlock.. they have been know to fray against the body of the tranny and arc out

and yea the TQC spins when the engine is running regardless of postion of the shifter.. this is how your pump works and pumps fluid through out the tranny..

 

Turn OD off to trouble shoot the TC locking/unlocking.

If it does it in park though, I'm betting it's not that.

Throttle position sensor or Idle Speed Motor/Idle Air Control would be the first things I'd check. They're both sensors on the throttle body. The TPS commonly fails, and it's common for the IAC to be dirty.