40 Ford Ignition Woes

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philipswanson

Well-known member
My son bought a 40 Ford truck with a 59A flathead. It wasn't running when he got it. I put new points in it on my Sun machine and set the dwell. It started right up and ran well. We went for a ride and all ran strong. We drove about 5 miles and all of a sudden it died. No spark condition. We called AAA and got a tow home. He changed the coil and it started right up again. He took it for another ride days later and the same thing happened. Had to get it towed home again. What do you experts think is causing this?? Help please.
 
Crab or helmet?

I have had problems with the HT side of the ignition. Cap and rotor can all fail under load, and run fine again until hot and loaded again. Have any spares you can swap on?
 
There are several items that with heat can go bad but when cold are OK. The ones mentioned above plus the ignition condenser.
 
I put a Pertronix unit in a crab distributor on my engine because these reproduction parts are so terrible.

But, if I were doing a stock ignition all over again, I’d buy a coil from Skip Haney and a condenser from Tubman.
 
It's a crab distributor. I think the resistor has been bypassed. I will have my son check it out tonight. Will let you know what we find. Thanks!
 
Fritz said:
But, if I were doing a stock ignition all over again, I’d buy a coil from Skip Haney and a condenser from Tubman.
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Did that with my helmet distributor. VERY SATISFIED! Car runs really strong and reliable. I'd be confident using it as a daily driver. Bought 2 each so I'd have spares. Also bought NOS resistors and points on evilBay for spares.
 
something worth checking is how the points fit on the pivot post, I just had one set of points lock up when it got hot so the 1 point was locked open so the distributor had no spark, was ok & tested good when it was cold but after driving for an hour or so the 1 set of points locked up, I have just drilled it out to give more clearance
 
The first thing I check when a car just stops as check if an ignition or gas problem. Take off the air cleaner and work the throttle to see if the accelerator pump squirts out gas. If so fuel is not a problem. Then pull a wire and hold it close to ground as you try to start. You should have a hot blue spark. With a crab distributor you have an external coil. So check the output of the coil with the spark test. If still nothing you know it is in the ignition upstream of the coil. Check the input voltage at the coil. If not there keep going back.
 
Juergen said:
The first thing I check when a car just stops as check if an ignition or gas problem. Take off the air cleaner and work the throttle to see if the accelerator pump squirts out gas. If so fuel is not a problem. Then pull a wire and hold it close to ground as you try to start. You should have a hot blue spark. With a crab distributor you have an external coil. So check the output of the coil with the spark test. If still nothing you know it is in the ignition upstream of the coil. Check the input voltage at the coil. If not there keep going back.
Click to expand...

We checked for a fuel problem and getting a squirt. No spark though. Next time we take it out, I am bringing a hotwire and a multimeter. Thanks!
 
just wondering where is the coil mounted had nothing but drama when i went back to a crab turns out the coil was overheating when mounted on the eng moved it to the inner guard problems solved you couldn't touch the coil it was that hot but now gets warm but you can hang on to it
 
We worked on it again last night. Put another new condenser and coil from Napa on it and as usual it started right up. We drove it about 50 feet and it died again. Pulled a plug and checked for spark and none. Turned key on again and checked voltage on the - side of the coil. 6.2 volts present. In my estimation, it has to be the cap, rotor or distributor. What else can it be?
 
Check the ignition switch at the steering column. Take it off and check the contacts. They get corroded and burned and cause a high resistance.
 
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