ghcoe wrote:letank wrote:The module usually fails when warm -after driving around- .
That is true for a run issue, but not correct for a start issue. Motorcraft modules have a start circuit that retards ignition for easier starting. It is energized by the ignition switch in the start position. If it fails you will not have spark to the coil while you are trying to start the vehicle.
Updating this old post because it was the one given when doing a search, so it may help others
It is so true.... it was time to move because of street cleaning... crank but no start... aaaaack... so I sprayed some starting fluid down the carb: no start... checked for spark with the timing light: no spark... the coil is old, it is the oem, ... I knew that some of the ignition wires were taped and brittle but the engine has started without any troubles for the last 18 months, this is the camshaft rescue 86 Gwag. I had to go to other venues, so left the hood up and put a sign to thank the meter enforcement people not to ticket me ($82 is the current fee)
No ticket... this july 86 has an 87 wire color scheme and some redundancy in the wiring, probably due to a fire... worked on the wiring, checked that module was getting voltage and that distro had proper resistance of 600 to 800 ohms on orange purple wire, installed spare coil: no start, swapped module: START, success... pffff
As a note I tried to retard the distro by about 5 degrees, and do some wiring bypass without success.
The failed module was no brand module, the grommet is rather purple than blue... the swaped module is a motorcraft junkyard find from a 89 Gwag with less than 120Kmiles
Post edit, found this more recent post with test help tricks, not the same key words
viewtopic.php?t=14889