surging

wrote in news:pHfWf.11101$k75.1860 @newsread3.news.atl.earthlink.net:

back yonder in them days GM had a prob with Mass Airflow Sensors in the 2.8 genre. rarely did it set a code..........instead of making a MAF sensor that would hold up they installed new software (chip) in the ECM that did away with MAF input and went to a speed density system...the MAF sensor was left intact because it fed the processor the IAT input also........if the alteration was done it should have a sticker on the radiator support, upper, indicating the repair (?).............if not, i would beg, borrow, or steal a known good MAF sensor for a try if no codes are present..........from a fuzzy memory, kjun.................

If the battery was recently unhooked, then the computer will need to relearn how to idle the engine properly. While it is learning the engine will idle poorly.

If you don't have a MAF sensor it may help to spray some intake cleaner in the throttle with the engine running. It won't hurt, they usually need a good cleaning after a while.

Vacuum leak is a likely cause though. You'll just love all the places they were put on your engine.