I have a 1990 Ford F150. Cranks but wont fire.
I have a 1990 Ford F150. It was running fine and then all of a sudden it wouldn't start.
It Cranks like mad and I can smell gas but it will never fire. I tested the ignition control
module (with a home made tester) and it tested fine.( One wire continuous 12 V, the
other flashing when cranking). I replaced the coil to no avail.I had the trucked towed to
a service center and they also tested the ICM(with a real tester) and again it was fine.
They then replaced the coil (again), and the truck will still not fire. Anyone have any
If everything is checking out ok the plugs must be fouled out and not firing.
I don't suspect that is the problem as it ran perfectly once second and not the next. Also there is no spark from the high voltage coil wire. I'm curious how the coil is grounded?
Instand of guessing remove one of the spark plugs out plug back in spark plug wire and hold plug close to a ground and have someone turn engine over you should get a spark if its firing. If you get a spark the plugs are not firing and if not check ground to coil.
I tested the main output coil wire and got not spark. I also did the test you are suggesting and again got no spark.
If all of the wiring checks and you still don't have fire out of the coil then it is a bad coil even though it is new, if you finally get fire from the coil but nothing at the distributor replace coil wire, however if the ignition wires have not been replaced in the past 3 years now would be a good time to replace them, so if you have fire at the distributor but not at the plugs replace the cap and rotor, and that should give spark at all of the plugs.
If know power going to coil check ignition fuse.
I have tried 2 new coils to no avail and I guess it is possible they were both bad. Is there any way to test a coil independent of the vehicle? IE some kind of resistance test?
Go to : http://www.ehow.com/how_5941137_test-ford-ignition-coil.html
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