Hi, im merlin. I own a 04 reg. 125 T 280, if i

I might be wrong but if it does have idle air control should be suspected. If you turn a/c on with engine running, one fan should turn on. Check for power at that fan first.

well gee, there are 50 reasons.
did you scan the PCM yet, if not ,why not?
when the idle surges, that means.
NO RPM ranges stated, if super low rpm check EGR.

1: engine lean and ISC dead, or cant handle the huge engine power drop..The PCM can even make this worse!, buy hunting the ISC to find spec, idle and failing... to...
2: or any of 50 other things causing huge engine power drop and PCM can't maintain idle controls.
super lean burn.(bogging)
super rich burn, misfire for 50 reasons.

i cant hear your engine,nor feel it, or see it shake from gross misfiring.
no can i drive it and see/feel power loss,
can I?
asking net bunny's this (blind as bats)
is "OVER THE TOP" no?
so here , ill toss the dice for you
and guess gross misfiring.
ever get a tuneup this decade, if not bingo , no?

and the others...

http://jeepdied.com/Misfire101.html

link even has the 50 cause list, to show the futility of guessing!
we do 1 to 10 tests. and find it.
for sure.

as you can see EFI systems are complex.
gue$$ is not only expensive but can net you 2 problems easy.

Hi there my name is Brandon I am a mechanical n electronic engineering technician you can field test the coil take a reg test light and ground it to the body not the battery and put the light next to the coil and pull the wire you will see the Ark and pull the light out bout a half in, and it should be very fast Ark and also I would check out the iac sin. With it running unplug it and if it is good you rpm will change but if its bad it will not do anything and maybe even die

Take a spray bottle and start spraying around the hoses on the motor, with engine running. When the engine slows down in any area, look for a broken hose and repair it. That should bring the rpm down.

The perils of used transmissions is all I can say is have it rebuilt.

control module behind the passenger side kick panel

Your engine is probably equipped with an 'Idle Air Control' that has failed.

hi..sounds like a loose connection in the ignition circut,
causing the tach to act up and the car to stall.
check this out..
thank u..
rate me..

it sounds like your torque converter is slipping, take it out and put in a new one.

The brake pads or rotors are worn or the tires could be worn.If you apply the brake and let off the steering wheel and the car pulls left or right i would suspect the brakes/pads,if not you may have an suspension issue in the front.