My 89 C1500 350 usually starts first try. Maybe once per week, it won't. At these times it will crank very well, and I may get a little smoke (uncombusted gas), so the issue seems to be spark, not fuel. Within the last year I've had a new distributor, cap/rotor, plugs, wires, ignition coil
and ignition switch. Could my issue be a crank sensor?
JA: Does the vehicle stall at low speeds? Does it sputter?
Customer: It hasn't stalled while driving yet. It will occasionally "dim", then rev back up. This can be accompanied by a lurch/clunk if I'm stopped at a light.
JA: What is the model of your '89 Chevy?
Customer: Silverado C1500,*****
JA: Are you fixing your Silverado yourself? What have you tried so far?
Customer: I often will, but the above fixes have been done in a garage.
JA: Anything else you want the mechanic to know before I connect you?
Customer: Only that it's been difficult for my mechanic to diagnose the issue, as it doesn't often "fail". At least not while it's in the shop.