slight studder while maintaining speed, and won't exceed 3,000 rpm while in gear
 

For the past few weeks my 1989 GTA has shown a slight studder while maintaining speed. No hesitation or chugging while accelerating, but will not exceed 3,000-3,200 rpm. (sounds and feels like a fuel cutout) I have changed a few parts and the hesitation has almost vanished. The exhaust system is leaving at the Manifold Y-pipe connection, and my first thought was that this could be causing the O2 sensor to malfunction.

Parts changed :
Belt
alternator
fuel injector (cyl 7)
plugs
cap/ rotor
ICM
Plenum gaskets.
Fuel filter
Air filter

Any ideas as to what could be causing this?

stick or auto if its auto your trans may be starting to slip

:bertstare:

The trans was on the growing list of things that could be causing the issue... Of course it is much more expensive than a simple sensor..

My car has the 700r4 trans

Check your base timing. it should be at 6* BTDC. 7 is ok too, as long as its 6 or 7.

I doubt the trans is slipping because then the engine would freely spin without the car going anywhere and you would definatly eclipse 3k RPM.

Okay thanks, I'll grab a timing light when i get a chance.

Make sure you unplug the EST connector with the car off. set base timing, turn car off tighten distributor plug in EST and start car and go for a ride