I’m having an ignition problem on my 77. If any of you mechanics have some advice I’d greatly appreciate it. It fired right up and I pulled it in the shop to change the thermostat. Fired up to check for leaks and it ran at high idle, it was cold, for a min or two and died. Like the ignition cut out. Turned the key and it fired right up. Ran on high idle for a min or so and died again. Fired right up and I pushed the throttle to get off high idle and it ran for 5 to 10 mins no issues and I turned it off. I unplugged the distributor and routed the plug different and plugged it back in. Won’t start now. Put timing light on various plug wires and it lit up like each cylinder is getting spark but won’t start. Sprayed starter fluid in carb just to make sure and nothing. If the ignition was bad I wouldn’t get anything with the timing light. Right? Could the distributor be bad and I’m still getting spark? I’m all out of ideas lol. Wondered if it’s just not enough spark so tried another coil and nada.

 

Almost reads like was a weak wire to terminal connection in the plug you undid to reroute the distributor wire loom.

 

Check your grounds first.
Next, you might try having your alternator and voltage regulator checked.
Duraspark module could be going on the fritz. If you replace the Duraspark, purchase an OEM Ford module.

Sure you aren't running out of fuel ?

With engine running, your battery voltage should be somewhere around 13.5 to 14.5 volts.

Keep us posted.

 

Anytime you have a problem with a durashart system the first thing you do is try another ECM. the Miotorcraft ones are also made in China now so older NOS ones are the best, but anything will work for now.

If the light is firing something is happening, but your spark could be too weak to fire. check the voltage into the coil.

 

I decided rather than mess with all the old wiring I would put an H.E.I setup on it and simplify everything. I went out to hook up the new distributor and figured I would try turning it over and see what happened. It fired right off. No clue how or why. Nothing was different or changed. Exactly how I left it the other day when it wouldnt start. Only thing was I had left a battery charger on it. I had hooked it up the other day because I was turning the engine over so much and didnt want to run the battery down. I am clueless but it worked. Still putting the new setup on it because I have it and it's less stuff to mess with. Also a better ignition over all. I appreciate the help and suggestions.

 

In theory it's a better ignition, but it's not.

You have junk gear and junk electronics in your imported set up. put an MSD gear on and Delco professional grade electronics in and it'll be okay if you can live with a GM F-series look.

 

Actually it’s made here in the US. Davis Unified.

 

I had a somewhat simular problem. I ended up replacing the coil and ignition control module, and have not had any starting problem in a few weeks. Coil was line 20ish and middle was 40ish. (I think). Both in stock at local parts stores.

 

After a few months and thinking I had the issue resolved it has flared up again. I thought it was ignition but now I am not sure. My original issue seemed to "Fix" itself after I let the pickup sit for a week. Went to the shop and turned the key and it fired right up. Drove it for a few months and seemed to be fine. However It didnt seem to run as well as it did before. When I was having issues before I had pulled the distributer to install a Davis Unified HEI setup. It was the wrong distributer and I had to send it back to get the correct one. So I put the old one back in. Finally decided to check the timing to see if that was why it wasnt running right and discovered the timing was retarded a bit. I advanced it and the old power came back. Few weeks later the starting issue flared back up. Turns over plenty fast enough just wont pop off. I'll leave it parked over night and come back and bam fires right off. I was out of town a few days and didnt start it for a week. Got in and it turned over and over and wouldn't start. Left it over night and same thing. Read online it may be fuel evaporating out of the float bowl, Edelbrock Carb, so Last night I just let the engine turn over for quite a long time. Just as I was about to give up it popped off. Turned it off and it fired right up again. This morning I turned the key and it fired up and died. Then back to turning over and over and not starting. Everything is new. Engine was rebuilt 2 years ago. New carb, distributor, plug wires, coil. I am not sure whats going on. When it runs it runs great. Lots of power and very smooth. Just doesnt like to start some times. One thing I noticed is sometimes turning the ignition on the engine will "Rumble" almost like a dieseling sound best way I can describe it. Just for a second. Enough to shake the truck. if I turn the key from off to ignition on and back to off each time I turn the key it does this. I apologize if this is all confusing just trying my best to explain what I am seeing to get the best chance of some information and help. Just unsure what to do. I havent put the HEI on it yet since i twas running so well for so long.

 

did you try any of the previously suggested trouble-shooting steps above like swapping in a known-good ignition module?
when it cranks over without starting, if you suspect a fuel issue spray a little starting fluid in the carb while the engine is cranking. if it tries to run, you have spark and need to figure out the fuel issue.
if it doesn't try to start, you need to troubleshoot the ignition side. A 12v test light on the negative post of the coil should flash when you try cranking.

 

I did try a different ignition module. It was an older used one so probably not the best.
I have never tested a coil. I will try that tonight.
While here at work I was thinking maybe the filter is plugged. I know in the past I have found filters in really weird places between the tank and fuel pump.

I appreciate the help.