omniserv

I have a question for everyone. I have posted on here on another post that my Z31 NA seems to lose power at mid throttle. Already done a serious tune up, including new plugs, plug wires, cap, rotor cap, new injectors, O2 sensor, fuel filter. tested the fuel presure and reg. as well. The ECU shows no codes.Also have ran all the test I can find in the manuals.

After all this the car does runs great when cold. Once the engine temp. gets warm it starts to lose some power. (2000-3000 rpm) If I didn't drive it hard you'd hardly notice. It does idle just fine hot or cold.

My new question is what differance is there between how a cold engine is managed by the ECU vs when the engine is at op. temp? Any idea's? I really don't want to take this car to Nissan at $90/hr to fingure it out.

Thanks

Chris