Coil failure ?

[Purdy Swoft]

The low priced ignition switches have caused this problem for me in the past .

[Dick Steinkamp]

Originally Posted by Conaway2

Update - new coil and condenser installed today, although both removed parts tested OK with my DVM. I have good spark now, and the timing is right on the mark, but the car will still not start. I’m puzzled, as there is plenty of fuel flow to the carburetor. tomorrow, I plan to take the carb off and check it out. The car died suddenly after I had just filled the gas tank to the top and was driving home at 40 mph or so. I would appreciate any bright ideas, as I am puzzled !

Just a word to others here.

If your A stops running, and everyone suggests it's the coil or condenser (as they certainly will). So you test them and they test good. DON'T replace them. Continue to diagnose until you find the problem. Replacing parts before the cause of the problem is known just introduces additional variables.

[30 Closed Cab PU]

Remove wire lead off spark plug. Place it 1/8 inch or so from the spark plug terminal - ignition on, turn over via starter, should see a nice blue spark across the lead to plug gap. Quick way of telling if you have spark.


Pull plug, smell plug for gas.

[katy]

Originally Posted by Dick Steinkamp

Just a word to others here.

If your A stops running, and everyone suggests it's the coil or condenser (as they certainly will). So you test them and they test good. DON'T replace them. Continue to diagnose until you find the problem. Replacing parts before the cause of the problem is known just introduces additional variables.

If you're guessing and replacing parts, only replace one part at a time. If you replace the coil and the condenser because the engine wouldn't start and it now starts, which part cured the problem?

[Jerry in Shasta]

Bought a new coil at NAPA. checked for spark, nice blue spark. Pluged i the coil wire it would not start, no spark. The long and short of it is, the coil would not throw a spark when firing under compression. Change out that coil ran fine


Moral the story, Just because it's new don't mean its good.
JB

[katy]

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It sounds like maybe you had a 12 V (3 ohm) coil?

I've had 2 coils fail on me over the years, not on Model A's. One was a '69 Ford 1/2 ton w/a 302, driving one day and the truck backfired and snorted a couple of times and settled down and ran fine. 2 or 3 years and many miles later it started running not quite right, felt like it was a carburation problem, disassembled, cleaned and checked over the carburetor and all was good. Truck still didn't run quite right. Cleaned and re-gapped spark plugs and truck ran good for a day or 2 and then started acting up again. Talked to an old timer friend and he said "it's your coil". So I replaced the coil and problem solved.

The other time a coil failed was on a '89 Ford Bronco w/a 351, it just quit and that was it. I was on my way to work and a work mate stopped and gave me a hand to push the car around the corner onto a side street for later retrieval.

[31 ford]

I had a similar problem until I finally replaced the conduit covered wire from the ignition switch to the base of the distributor. My original one had dried out and in many places missing wire insulation and would ground out .

[31 ford]

I had a similar problem until I finally replaced the conduit covered wire from the ignition switch to the base of the distributor. My original one not only had dried out insulation but also missing insulation and would ground out.

[Conaway2]

31Ford - that is exactly what my problem turned out to be...my ignition cable inside the conduit was shorting intermittently.....new cable arrives tomorrow (I hope) - I’ll post an update. For all I know, the original could may be good, in which case I will re-install it and keep the new coil as a spare.

[Conaway2]

Last post on this - I installed a new ignition cable/conduit yesterday, and immediately had a very strong spark from the coil. The car started right up. In hindsight, I should have gotten my DVM out first thing to troubleshoot the issue - hope I remember this in the future. Anyway, with new points, condenser and coil as well, the car should be good for a while.

[31Abone]

I bot a new 6v coil from one of the parts houses couple of years ago..30 model A..car would run fine in my yard but at speed it missed badly so I checked spark at a very fast idle speed !! no spark at speed ,so in the ditch the new coil went and found a old 50's coil works good since..be ware junk products on the market....sc