My '93 SC300 (175,000 miles, original owner and have had the car maintained by Lexus all its life.) has a jerking problem that is occuring upon lightly applying pressure to the throttle when driving, no matter what speed. If I apply moderate to hard pressure to the throttle, no problem. This jerking does not occur on ever start. Only about 1 out of 6 starts does it do this and it will run that way continuously through the same start. All other times, no problem. I have recently found that when the problem occurs I can stop the car, turn off the engine, restart the car, drive away and the problem is gone.
I have taken the car to 2 different Lexus Dealers to repair this problem. Each said that I had a Head Gasket issue that needed repaired. After spending $5,000 in replacing the Head Gasket and other service repairs, I still have the original problem (however, the car is running great now when it is not jerking). The Lexus Dealer that I had repair the Head Gasket can not figure out the problem, because it can not be replicated every time.
This is puzzling because of the inconsistancy. Has anyone else run into this same issue?
Also, today at lunch it starting jerking again. Instead of stopping and turning off the engine, I put it into neutral, then back into drive and the jerking on light throttle pressure stopped. I was not able to replicated it after that. I plan to continue this avenue of testing in order to narrow it down.
Lexor