ENGINE BREAKING UP AND MISSING BETWEEN 5000-6000 RPM

[MVR 155]

Originally Posted by CONRAD II

Do you have gauges monitoring your air/fuel ratios? If so, are you running lean, rich, or are you at 14.7:1? I have the mag charger also, and if I am at idle or under boost I never ever run lean. Sometimes while in vaccum I do notice that I am running lean (sometimes as much as 16:1), but my engine runs/sounds fine. I hope I'm not about to start having the same problems that you are....

16:1 is waaaaay lean, if you are really at this A/F ratio I can assure you that you are very close to some serious problems (if there isnt already damage)...... even 14:1 is too lean, with a supercharged (or any other F/I induction vehicle) I wouldnt go over 13:1 personally since you want to leave a small buffer for bum gasoline and extreme conditions. Im a firm believer that whenever you do a major mod (such as internal motor work, forced induction, nitrous etc....) that it should be dyno tuned with a wideband A/F to get the max performance from the set up as well as be within safe parameters from detonation.