I have a '91 straight 6 that won't start. The starter motor cranks but no pistons are firing. I narrowed it down to a fuel issue, there is no fuel pressure coming out of the schrader valve so I believe it is a fuel pump. But I figured a couple pistons should still fire with the help of starting fluid, I had a buddy crank the engine as I squirted the fluid in the throttle body (which I cleaned a day ago) and still no pistons fired. I checked all the spark plug boots with a timing light and the light was blinking when the engine cranked so the spark plugs are getting a pulse. I pulled the spark plugs, cleaned them and reset the gap and tried again but still no joy. Any help?

 

Ignition coil can produce spark, but a weak one can't ignite the mixture. MSD ignition coils are known for this. I've been through 2 of them in 6 years. This is why I suggest just Motorcraft ignition parts.

Have you checked primary and secondary resistance for the coil?

When did this problem start? Or did you inherent the problem?

Have you checked the distributor mounted ICM?

Try pulling the SPOUT connector to disable the PCM from controlling spark and see if you get it to fire.

 

Check/reset the inertia switch.

I'd also try to pull EEC codes and see if it can tell you what's up.

 

timbersteel - I focused more on the ignition coil and the ignition control module, there was no spark coming from the ignition control module when we tested for it. We checked the wires going in with an LED and when cranking the light did not flicker it was a solid light. We traced the wire to the ICM and again used the LED to find that it was solid when cranking, no flicker. A buddy of mine had an ICM laying around that was never used in a vehicle before so we put the new one in and connected it and still no joy. All of the tests we performed came from here:

Part 3 -How to Test the Ford Ignition Control Module (Distributor Mounted)

My next step would be to put in a ignition coil, no?

BaronVonAutomatic - We also tried pulling EEC codes but no luck