My 86 f150 will start great and run when cold, but when it warns up it won’t start. I will turn over strong, but it just won’t fire. I have replaced the ecm and the Icm. What else could it be?
Fuel pump comes to mind, figure how to test it in failure mode or if you are not a DIY guy have the shop on ready for when you stop by and have a no start symptom. Let me guess, after 45 minutes or so it starts fine?
Buy a cheap spark plug tester from Harbor Freight and a can of starting fluid. When it wont restart, pull a plug wire and put the tester between the wire and plug and try starting. If it doesn’t flash, your problem is electrical. If it does flash. spray starting fluid in your air cleaner and try starting it again. If it starts your problem is fuel delivery. If it still doesn’t start and you don’t smell a strong gasoline odor from a flooded engine then you have a problem like I have never seen.
Sounds like the heater core to me.
@kawasaga ha ha?
No disrepect intended, but are you sure you’re responding to the correct thread?
The problem might caused from a defective magnetic pick-up coil in the distributor. http://www.rockauto.com/catalog/moreinfo.php?pk=951144&cc=1121667
Tester
Yes Tester. That pick up coil fails about as often as the module and I found it was good business to always replace both if either failed. For the DIYer replacing the entire distributor is the simplest and cheapest solution because pressing off the gear without the proper equipment usually breaks the gear and the rebuilt distributor is relatively inexpensive.
Often failing plug wires and rotor cause the pickup and module to fail and bear close inspection.