i have been having an intermittent problem within the last 3 months or so but the prblem seems to be occuring more often with each passing week.1990 5 speed with 165k.engine dies for a brief instance, ranging in length from a fraction of a second(feels like a jerk) to as long as maybe two seconds.it restarts by itself as the inertia keeps car moving forward since it is a stick and engine keeps turning.i have noticed the following when this happens.tach drops depending on how long the engine "dies", when it dies for a fraction of a second the tach drops about 500-1000 rpm instantly. when it dies for 2 seconds tach drops to zero.speedometer doesnt drop at all. also the upshift light turns on when this happens. am i correct to assume that the upshift light comes on when the pcm looses the signal from the crank sensor ? thus indicating a defective sensor? i am probably going to replace the crank sensor but i would like to know if a faulty dis module and/or cam sensor will also cause the upshift light to come on and tach to drop?