This is driving me crazy and I've thrown 3 Ignition modules and now 3 ignition coils at it. At turning the key to start, I have 12 volts at + on the ignition coil and using an LED test I have +12 volts to ground pulsing (LED FLASHING). I'm also using an HEI spark tester but no spark. Previously I wasn't getting the pulse out from the ignition module but the coil was unplugged. It needs to be plugged into the coil to pull up the ignition pulse I guess. ADDITIONAL I've used a cheap Velman scope to look at the PIP of the ignition module. A very clean square wave. I've looked at the output coil pulse at the ignition module and the ignition coil and the waveform pulses but is very noisy. As an electronic tech I've used an oscilloscope but never on an ignition system.

 

ive never really looked at a 93 3.0l but one time on a 1994 f150 i had a similar problem one of the wires on the tfi had pulled out of the harness at the plug in for the tfi, it was out just enough i couldnt see it untill i was looking into the plug. does the 93 have a dizzy or coil pack?

 

Its got a distributor and I've messed with that TFI like crazy. replaced it 3 times. I check the power and pulses with a pierce probe at the TFI (ignition control module). It has power, ground, PIP from the distributor and I cut and by-passed the TFI output to the distributor because it looked trashy with a cheapo scope. I need to find what a good pulse looks like to the distributor. ARGGGHH!

 

have you tryed changing the dizzy? hall effect sensor may be weak. a junkyard dizzy cant be that expensive. its been a while since ive messed with distributors so im refering to my 5.0 and 2.3l mustangs. ive had one bad hall effect sensor. it seems like thats the only thing you have left in the circle of things to change.

 

You might be onto something. The PIP pulse is there but peaks about 8-9 volts. I replaced it about a year ago when the gear stripped out. After market is usually not as good as genuine. I replace the starter twice in one year. I'll let you know. Thanx.

 

Somewhere along with bypassing some harness wiring I'm embarrassed to say I blew the EEC/PCM fuse. Even though I had a pulse coming out of the ignition module, the EEC still had to provide something to the Ignition module to fire the coil. Replacing the fuse, all is well. Thank you for your input.

 

awesome! glad its running again