Ive been dealing with a loss of spark on a 89 152,000 miles this began after I parked the car for a month to replace the intake gaskets due to a coolant leak. I lose spark at random anywhere between 20 seconds to about 5 mins, the car just shuts off no sputtering or coughing and all lights, radio, heater everything still works the engine just quits. Whats really weird is if I cycle the ignition key on/off or disconnect the tfi harness (more specifically ive narrowed it down to just disconnecting the power run wire to the tfi which still has 12 volts when it dies ) it restores spark and instantly starts. So far I have tested codes and none were found, I cleaned the ecm ground and secondary ground off the backside of the engine to firewall and any other ground I could find. Ive tried 4 known good tfis (two were brand new a standard, 2 napa and one motorcraft units and i apply a light layer of thermal grease) I checked voltages on the tfi plug and everthing checks out according to a tfi troubleshooting flowchart I found on this forum. I went on to also try two coils, a spare ecm from my friends running 89 mustang and new napa distributor which I made sure to check that i have a good pip signal going to the module. My latest attempts have been to replace the igniton switch and I used two working fuel and ecm relays off my friends running car. I have also taken the wire harness off the engine and gone through looking at wire integrity and continuity to the best of my knowledge and it appears fine. The problem is also unaffected by having the spout in or out it dies either way and only starts after the key is cycled or disconnecting and reconnecting the tfi. I was just wondering if anyone would have any insight or new direction to go in troubleshooting? Ive also been through numerous troubleshooting guides for the tfi with my dvom and all signs point to a tfi issue i just cant fathom how disconnecting and reconnecting power fixes it let alone 4 other tfi modules having the exact same issue. From my understanding the tfi has power, is getting a pip signal, i can even trigger the module on the pip wire and hear the fuel pump and relays click but it doesnt ground the coil, it seems as if the module just stops grounding the coil but the minute I cycle the key or unplug and reconnect the tfi it works flawlessly for a few seconds to minutes. I am at a loss and was hoping maybe someone has had a similar issue and could give some insight or new direction for troubleshooting? Thanks again.