spark at the wrong time.

could be cap or rotor. back in the days, it could also be a failed camshaft.

have it checked to confirm

Roy

I have a 1993 Chevy s10 2.5 le iter. My mufler exploded. It runs rich. It. Back. I?n in 4th and 5th.gear loosesi loose significant power on small inclines. My pre ignition check engine. Works)s but doesn't warn!!! me of any problems