Guys n Gals this is a new one to me. I've read what I could find on here & I think I've found my own answer but here we go. Keyed ignition turns on normally, truck turns over no problem, fires right away, then stops. It will do this for a bit. I check the grounds, wire connections, look around trying to find some kind of clue. Eventually it will start like normal. It runs just fine once started. It does this cold or warmed up.
I confirm fuel was getting in by just looking down the carb so I don't think it's that. Just to be sure I'm changing the filter.
Anyhow the problem seemed similar to some other's posted on here. I think it's the ignition control module.
What do the huddled masses think?

 

Why not replace it and see and if it still dose the same thing you now got a spare.
Dave ----

 

I had one off a junk truck I put on it for now. It still displayed the same symptoms but I've not adequately tested it yet. I also just received a new one that haven't gotten to install yet.

 

Most often when the ICM fails it just won't run. but anything is possible.

A bad pickup coil can cause your symptoms . try to find an older US made one on ebay or somewhere. the imported ones are crap and that includes Motorcraft.

 

I know I'm gonna get ragged on by some in my upcoming post like I done before, reference to the dura spark ignition system....

What I done - On both my 76 Lincoln Mark IV back in 2005 (my youngest vehicle that I still own to this day), and my 75 F250 Ranger XLT Camper Special back in 2016 was :

I removed the dura spark distributors, removed the ignition modules, installed point distributors, removed points, installed Pertronix II kits and Flame Thrower coils and had great reliability ever since with no issues, no need to keep buying and carrying spare modules for those two rigs and then find out on another occasion the pickup sensor on the distributor was intermittent also.

My other 7 vehicles are pre 1974 (my other five Fords and two Dodges) and were all Pertronix converted and never had an ignition related issue with them other than counterweight springs or distributor wearing out due to long life usage.

I can't confirm on this, as someone told me they purchased a compatible MSD module for their factory dura spark ignition and had no issues with it....and has yet to replace it compared to the typical aftermarket ones out there that only last so long.

That's my two ounces of gold on my opinion, ....as if someone were to offer me two cents to buy a dura spark distributor and module package . . . I'd be paying TOO MUCH !!!!

 

If you've tried more than one ICM, and the problem remains, it's probably not a faulty ICM. As suggested, it could be the distributor pick up coil (stator). It sounds like your situation is intermittent. You can test the pick up coil with an ohm meter. Between orange & purple wires should be 400-800 ohms (preferably 600-650 ohms). Between either orange or purple and ground (black) should be infinite. These are guidelines. The "good" coil is the one that gets the engine to run properly. As mentioned, made in USA coils are to be preferred over made in China.

 

How is the wiring in the truck? The ignition switch has a Start-12V wire that powers the ignition when cranking and a Run-12V lead that powers it once started. Check the 12V Run circuit for bad connections. Also check the switch and key cylinder for excessive play.

 

X2 Stick a test light probe on the positive coil terminal and see what it does while cranking and starting.

 

440 sixpack So at the time I didn’t get to check more than 2 starts before I had to leave. First key turn same thing. Second, she fired & ran. I don’t know if the 2nd used ICM fixed it or if I was just lucky. I started it today several times with no issues but I’m not convinced.

Aksilvereagle this sounds like the way to go in the future but I need to look into what parts & work I need to do for this. If what I have is able to work sufficiently then what you’re suggesting would be a nice but not needed upgrade. The truck I’m working on now is my daily driver. I have another that I’m going to restore completely with as much oem as possible so any parts I buy for this ignition may go to that & I’ll upgrade my daily in the future.

Ozzie H. & 5851a. I was wonder if there was a way to test the coil on the truck & the spare I have thank you both! Having the parameters that it should fall in makes it much easier.

spedfreak78 my key does seem to have excessive play & another recent development is my radio will just lose power while driving. It seems like jiggling the key will bring it back but that may just be coincidence. Radio is aftermarket & without looking I don’t remember where I pulled power for it from.

Thank you all. Having multiple opinions & things to troubleshoot this issue is great because outside of swapping the parts I really didn’t know where to begin on this one.

 

Ever since these were new it's been common practice to carry a spare ICM in the rig. I'd find an older US made NOS one and install it then keep the one you have now under the seat.

I'd replace the pick up coil as well . you can often find older NOS Motorcraft one or older Prestolite or standard brand. just as long as the box says USA made on it. skip the Chinese crap it's barely better than nothing I've had so many failures with it I'm disgusted.

I've found US made everything for all my durashart equipped rigs on ebay . the new Ford stuff is import crap too don't let the name fool you.

 

I think I figured it out! The coil ignition clip green wire had broken off awhile back. I repaired it by putting a female electrical connector inside the plastic clip housing. It fit pretty darn nice & worked just fine until now. I have a new connector that I ordered when it first broke I’ve just been holding off. Anyhow symptoms of not starting returned today & thanks to you gents I looked at the coil & saw the repair I made! I wiggled that connector, turned the key & she fired right up! So this weekend I’ll repair it properly with the new connector & get back to you!

 

Gaaaaaahhhhh! Fixing the connector, new ICM, and new ignition coil did not fix it! Truck turns over, fires immediately, & quits. It runs very well once started. I need to test this more but I’ve had success starting it jamming on the throttle while starting it. Could his mean the fuel pump is starting to go? I changed the fuel filter also. Old one was still clean as can be so I kept it. I don’t really know what else it could be.

 

Could be a wiring or continuity issue, could be a weak distributor issue, could be a distributor pick up sensor issue, could be ignition switch related issue, could be a new ICM issue as well - who knows with that duraspark ignition system unless one throws on the multimeter and do the mad scientist thing upon diagnosing all these components - that is why I hate the duraspark ignition and went with the much more trouble free route on my previous post and never had any of them stupid problems since ...and soooo love the hassle free freedom that the point distributor Pertronix II mod and 0.6ohm Flame Thrower coil with direct 14 volt conversion gives.

 

I'm not in the "huddled masses", and I don't trust the Duraspark ICM for a two mile trip. Like 440 said, they've been a common failure point since new. I remember them failing on all our farm trucks within the first year after purchase, and once I had to replace the ICM on my '79 Bronco twice in one week. We carried spares in the trucks and had spares on the shelf in the tool room. Those spares didn't collect dust. When HEI became available, I installed one on my Bronco and never had trouble. I've had HEI on my current truck for over four years now with no trouble. And the new engine I built for this truck has a MSD ignition system. HEI is the most cost effective choice.

 

So as a close to this thread for those viewing in the future, after swapping one part at a time, the issue has been resolved with a new ignition switch. Thanks to everyone for their advice & recommendations!