My 87 turbo idled fine at 700RPM. I cleaned the throttle body and now it idles at 1000RPM. Everything I have read shows how to adjust the idle on non-turbo models only. I cleaned the throttle body because the car idles rough when cold, which did not fix the problem. I am going to replace the air regulator today or tomorrow hoping thats it. Would that also cause it to idle that high.
Robert

 

Not to difficult to do even though manual wants you to use a special harness. Turbos idle is controlled by bleeding air from the idle circuit.
Warm car up to normal operating temp. Rev up 2-3X to clear throttle & injectors. Idle @ 2000 rpm for 2 minutes. return to idle and turn off car for about 15-seconds (key completely off. Re-start and adjust air bleed valve - it is on the upper intake plenum (square aluminum plate that says 300ZX Turbo), air valve is hanging off drivers side on top. Place short blade screwdriver parallel to plenum and insert into adjusting screw. Counterclockwise raises idle speed. Adjust and turn off car for a minute and restart. This will not effect a rough cold idle problem.

Might check the cold start enrichment circuit which is driven by a coolant sensor in the front of the engine right above the timing belt cover - Many times it's the culprit. Good luck

 

Also - You can take the trim panel off by your passenger Right-side kick panel and you will find the ECU. Take the two bolts off that hold it and leave it all plugged in. (If you do un-plug any ECU harness FIRST undo the negative battery cable). You will find a idle speed potentiometer (idle speed screw adjustment) on the top of the ECU that was adjusted at the factory. You can play with that, but I recommend the idle air bleed valve first.

<P ID="edit"><FONT class="small"><EM>Edited by texp51 on 07/18/02 09:17 PM.</EM></FONT></P>