91 teg runs rough when hot

I just bought a 91 teg ls with 171k miles on it. It starts fine and purrs like a kitten on a cold start, but as it warms up it gradually begins to stumble while idling until it is fully warmed up and running very rough. When I am driving it, it tends to stumble under full load, wide open throttle, and lower rpm's(under about 4k). Basically the motor is constantly sputtering and only giving me about 50% power until it hits about 4k rpm's OR I let off the gas a little. At this point it just kicks in and gives full power until I shift up again.

Could somebody at least point me in the right direction with this? Am I dealing with an ignition problem or an air metering problem? Initially I thought of the 02 sensor since the problem only shows up when the motor is hot, but the 02 sensor kicks in all at once, not gradually as this problem tends to show up. Doesn't seem like an ignition problem to me either since it is related to throttle position and load, but Im really not sure.

Let me know if any of you have experienced this problem or have informed suggestions about what I could do to fix the problem. Thanks!

I would check your Ignition system first. Espescially the Ignition Coil inside the distributor. They commonly burn out causing stumbles, misfires & hesitation - mostly when warm. Remove the coil from the distributor & reomve the tin metal shield from the coil. Check for burn marks on the coil or shield. This will appear as a white or light gray & black marks on the coil. Replace it if there is any signs at all. Also check the condition of the distributor cap & rotor along with the ignition wires. If they need replacing use good old genuine factory Honda wires etc. Nothing else fits better or last longer. You'll be glad in the long run.
Oxygen sensors will not generally cause a rough idle in most Hondas & Acuras. However they will cause stumble & hesitation, but rarely a misfire.
One other thing to check would be the coolant temperature sensor (Honda call this a T-W sensor). Usually located on the side of the cylinder head beneath the distributor, if faulty, can cause the engine to run too rich.
I hope this can be of some help to you.

I have been a Honda / Acura Technician for 22+ years now. These are some of the most common problems I have seen.
Good Luck. -Alan.

thanks. Ill post on what I find when I get time to look at the car.