just to add my 2 cents... I had a 93 ford taurus and I was told that the ignition module which was mounted on the distributer or in that area was getting 2 hot from engine heat and was cookin them so they moved them to the fire wall on the newer models, so like djg372 and jktsail said if there is an ignition module on your trucks and it is in, on or near the dist or really close to the engine this could be the problem even though my example was a ford... BTW I do own an 89 s-10 pick up. please let me know if this helps anybody