so i have been having a probleam with the duraspark set up on my 73 comet. i got the engine out of a 75 ford granada. it's a 351w and it runs pretty good. i had it running and driving. well i took it over to my dads shop to get the inspections and immisions done on it and it died there and i couldn't get it running again. so we asked a few people and they said that it sounded like the control modual was going out. so i got a new one threw that on and it didn't work. so another person said try and change the stator that could be your probleam. that didn't work. then another guy said that the resistance on the wire going to the coil cold be causing it to not be getting enouph spark. so i jumped the coil right from the batterie and it started to run really well. i went and got my dad and it stoped running again and i couldn't get it to sart back up. it would run as long as you kept the starter turning. so i was thinking that it could be my coil. i tested how many volts were coming out of the ignition switch to the coil and ti was 12.3 and the batterie was at like 12.7 so what i was thinking was that there was too much resistance through the coil and wasing getting enouph spark down to the plugs. any one have any ideas i'm going to be putting on a new coil today and i hope that works.
Only run when the starter is turning? There is 3 power wires on the duraspark system(if I remember correctly) power all the time, hot in run, and hot while cranking. you should check those out. did you check the fuses? If it's a factory coil look up the specs in a chilton book and measure primary and secondary resistance. It's probably not the coil if it runs in start.
Sounds like a combination of mismatch wiring and points ignition circuit... The resistance in the points ignition wiring could have fouled up the electronic components it seems to me. How hot was the coil? If a coil is going bad, a symptom is often that the coil will run fine when cool, but will break down when it gets warm or hot depending on how far gone. Could be something as simple as a bad wire though...
Normally the start circuit is direct thru the ignition switch to provide a higher start spark. When the motor begins to run then the run circuit thru the ignition switch tranfers to a series resistor to feed the box and the coil. If this run circuit is open then the motor will fire but stall in the run position. On the Mav/Comets this series resistor in in the harness out of sight so you don't know about it most of the time. It's easy to test the start and run circuits with a meter. BTW most all the 5L efi use a seperate start and run circuit thru the ignition switch to the TFI for many of the same reasons. If your wiring is home engineered then you just have to look until you find the problem.
i've checked and double checked my home enginered wiring. the thing was the car was running and it was running really good. there is only so many wires to check. the reason i think it's my coil is that it took me hooking the coil strait to the batterie to get it to run. so i initialy thouhgt that the resistor in line to the coil from the ignition switch was to blame. but then i went and got my dad and it would run jumped off the batterie any more. so it made me think that the coil is bad. yeah i did have the car running for a few minutes when i got it started so it had enouph time for the coil to warm up.
After sleeping on it, I was wondering why we were all focusing on the ignition... You say the car ran great, but you never gave us a concrete reason to believe the ignition was breaking down. If it ran great the way you had it wired, and you are replacing stuff left and right, getting the same breakdown, is it not more likely that you have something else? Maybe trash in the carb, for example. What you describe could easily be a fuel problem. Have you tried starting it, then keeping it running with fuel when it starts to fumble? Maybe you are suffering an intermittent vacuum leak... Did you do anything special to pass emissions? That is when the car broke down... Did you use the additives and such that are supposed to help you pass? Just some food for thought. Dave
