I have a 1988 S10 we bought brand new. It has 236K, 70K on reman motor. When you first start it, it idles rough and surges like crazy on idle. Sometimes it will stall. When accelerating and shifting from 1st to 2nd, or most any other gear, it'll " miss" and do a momentary " buck" when releasing the clutch and giving it gas. It'll do the same thing if you give it half throttle very quickly when idling. It runs fine down the road and once warm, it seems to idle better, without the surging. I have replaced the idle valve (that WAS bad), the O2 sensor, wires, cap, rotor, plugs, fuel filter, air filter and it still does it. I just replaced the fuel pump with a new AC/Delco pump and that did not help. I am told it is running lean but the sensors seems to be working according to the scan gauge. I tried a different MAP sensor and that did not help and the timing is also correct.
Sunday, July 8th, 2007 AT 9:11 AM