Die truck
1 Answer
Hornet_2497 answered 5 years ago
I was going to say crankshaft position sensor but your engine doesn't have one. It's going to be something electrical in the ignition system like a loose wire or bad ignition switch. The tachometer gets the same pulse signal as your ignition/spark. Whatever makes the tachometer drop suddenly, is also stopping your spark suddenly. Can you scan for codes? This pre-1996 truck has the OBD 1 system, not the OBD 2 that is currently scanned.