93 Surge at part throttle

[whitrock]

93 Mtx does not surge at idle. Surges upon acceleration & part throttle{crusing in 4th gear about 45mph}. It does not do it with ac off. I cleaned the maf & throttle body{on car}. Had po521 power steering pressure sensor. Replaced still same thing. It's not as bad in higher gears. It almost feels like the compressor is cycling...checked it ok. I did 60k service about 8000 miles ago. Replaced crank & cam sensors in the service.

 

[frosho]

Clean your IAC and reset the idle. See if it gets any better. I had one do the same thing before. It seemed as though the IAC was cycling along with the compressor as a means of canceling out its drag.

Idle reset procedure: http://www.shoforum.com/showpost.php?p=90952&postcount=2

 

[TYSHO]

Have you checked your fuel pressure? It can be a weak pump needing replacement.