My 88 M5 is experiencing a hesitation/surging problem. Iíve checked some of the archives and have seen similar problems posted but Iíve seen no postings to what the fix/fixes were. The problem is not dramatic but you can certainly feel it if you hold the RPMs constant while driving. Also, while in neutral, if I try to hold the RPMs steady around say 3K while in neutral, the Rs will hunt around, +/- 500 or so. The idle is steady at 650 and throttle response is good. If I get on it hard, I can the hesitation throughout the entire RPM range. Iíve replaced the plugs, cap and rotor and also cleaned the wiper on the air-flow-sensor. I guess I still have to consider the wires, coil and maybe the O2 sensor and injectors. Any suggestions on how else to troubleshoot this type of problem or isolate to electrical or fuel? I guess I can always take it to the shop and have them put it on an analyzer.
Thanks for any suggestions,