QuestionI have an 86 200SX with the VG30-V6 engine, auto,ps,pb,etc. At start-up, the car runs fine, when it reaches operating temp., it developes a severe hesitation-surging at approx 1900 rpm. Above 2000-2100 it runs ok. I can turn the car off for a few seconds, restart, and the problem is gone. The car runs great before warm-up and after restart. I have taken the car to 4 different dealers, one keep it 4 weeks, and followed the service manual diagnostics myself, but cannot resolve the problem. The problem started around 60,000 miles, after the 60,000 mi. service done by the dealer. All service since has been done by me, including replacing the engine due to a stripped timing belt at 225,000 miles. I now have about 245,000 miles on the car. It's a great car, but I have put up with the problem a long time and would like to remedy the problem. Any help would be greatly appreciated.
AnswerAlex,
I would ohms check the throttle position switch for the presense of a dead spot where you describe the hesitation. Basically, with the engine off, you connect the ohm meter and then move the throttle and check the reading. If there is s drop mid throttle you know the sensor is defective. Other causes for your condition are a defective distributor (Bad optical sensor) or oil contamination. Email me back with what you find.
