Got a 89 F-700 with a 429 factory propane engine------this appears to me to be the Duraspark II ignition system.
Bought this truck several years ago-------but, have randomly had ignition problems over a period of several years---but recently have been going through problems with the coil heating up. Just replaced both coil and brain box module-------coil heated up and engine quit in approximately 10 minutes run time. Let cool down-------cranked back off again.
I have an aftermarket tach wired to the coil on the negative side (same as factory wiring harness).
Anybody ever have problems with these aftermarket tachs heating the ignition coils up?? (am going to try without the tach hooked up tomorrow)
What other suggestions to look for here--------all voltages check on the money across the system.
I moved the follow up on this question over to the 80-------86 model F-150 forum. The F-700 appears to be running the same Duraspark II system that my old 84 Bronco had. Lots of Duraspark discussions over there.