I have been having an issue with my truck (1979 F150 w/ 400) lately where it will not start after it is warmed up. It cold starts every time and runs/drives with no issues, but after the engine has warmed up, if I shut it off and wait a few minutes, it will not start. I know that it is not a fuel issue because it wont even fire if I squirt starting fluid into the carb. I read through a few older threads from people who had the exact same issue. They both mentioned swapping out all sorts of parts and the problem persisted. The solution for both of them was distributor related so I am fairly certain that is my issue.

One guy wrote "After a lot of troubleshooting, It turned out to be the magnetic pickup in the distributor. Would run all day long until you shut it off. The heat soak into the distributor when the fan quit moving air would heat up the pickup and create an open. It was really hard to diagnose as it would cool off with the distributor cap off. Happened to catch the needle on my multimeter move as it went from open to ok. Drove me nuts for a few weeks. New pickup and no more issues."
Another guy wrote "replaced the distributor with an HEI style one(Summit Racing SUM-850026 - Summit Racing® Blueprinted HEI Distributors - Application - SummitRacing.com) and it seems to have done the trick!"


My question is, do I need to replace my entire distributor and should I go with an HEI style distributor? I have read about fitment issues with the thermostat housing as well as the air cleaner, has anyone put an HEI style distributor in a 335 series engine? Did it fit? Is it worth it?


Can I just replace the magnetic pickup in my stock distributor?

 

Sounds like the pickup coil and I've been through that drill. If indeed that's the problem look for an OEM Ford Motorcraft item, ebay, etc. The Echlin version from Napa should be fine also, but make sure it's not the Mileage Plus version. I found the Motorcraft one on ebay, good to go. Could also be the ignition module, possibly even the coil. Good luck.

John

https://www.napaonline.com/en/p/ECHM...ut=distributor

 

It could be the Duraspark ignition module. From what I've read that is more common than the distributor.

 

Thanks for the reply. Do you have a method of verifying if it is in fact the pickup coil that is the issue?

 

The 3 step scenario of a failing DuraSpark ignition module:

1) Module overheats, engine dies. Module cools down, engine restarts almost at once.

2) Module overheats, engine dies. Module cools down, engine restarts in an hour...or so.

3) Sooner or later, usually sooner...the module overheats, BURNS OUT. Now the engine will not restart.

Module located on the left fender inner apron, just in front of the firewall.

Engine heat, especially when radiating from the V8's red hot left exhaust manifold, is the mortal enemy of these modules.

Taking the module to an auto parts store to be tested. Will test OK unless the little charmer has burned out.

When replacing, use some washers to space it further away from the apron, the more airflow the better.

These symptoms may also affect the stator aka magnetic pickup coil inside the dizzy.

D4PZ-12A112-A .. Stator aka Magnetic Pickup Coil (Motorcraft DU-1A) / Available from Ford & auto parts stores.

1974/79 all FoMoCo V8's except 1979 LTD/Grand Marquis 351W with EEC (onboard computer).

 

The duraspark distributor is fully compatible with the GM HEI module, I have done a few conversions because the availability of genuine duraspark boxes have dried up. It's a easy afternoon swap and you can get a GM HEI module anytime from any parts house. If you decide to do a full HEI swap make sure to use the small cap style and there will not be any clearance issues. I like the one from CRT and you get the Packard wires which are considered the best wires available and really the last remaining domestically made.


Link to CRT

 

1U2Z-12A199-AA (replaced D6AZ-12A199-A & B, D8VZ-12A199-A, D9VZ-12A199-A) .. DuraSpark Ignition Module - blue grommet (Motorcraft DY-893) / Available from Ford & auto parts stores.

1976/90's FoMoCo vehicles.

1974/79: Besides the blue grommet, there's also a black, green, red, yellow and brown grommet module. None of these interchange.

 

The 893 box that Ford sells under the Motorcraft brand is the same import box that Napa sells. They no longer have any Ford or Motorcraft markings on them. The last two I purchased were made in China and they don't last.

 

 

There was a limited supply of the 12A99 boxes with the blue grommet that surfaced. I bought a few and all had 1988 codes for the box print codes. Some vendors are using the image but shipping the newer import boxes.

Standard looking import box also being sold in Motorcraft boxes.

The image shows the NOS boxes that came to market about a year or so ago. I paid about 100.00 a box for them, the 30.00 boxes are the import boxes. Including the motorcraft boxes, the new motorcraft boxes feel incredibly cheap, pretty sure the housing is zinc not aluminum.

 

HEI I have a new China-made Standard Blue streak box and its not too bad looking. Original Motorcraft boxes are all over eBay and junkyards still. I'd go with replacing pick-up first and having box tested next. I believe you can check pick-up with ohm meter.

 

I've been running a Summit HEI on my 400 for two years now. When I bought it, I figured it'd just be temporary while I was building the engine and truck. Never one bit of trouble out of it. If it fails tomorrow, I'll replace it with the same model. https://www.summitracing.com/parts/s...view/make/ford

If you're using the original Ford air cleaner there probably will be fitment issues because of height. If you're using a 14" round aftermarket type air cleaner, you'll probably have to use spacer between carburetor and air cleaner, and/or between carburetor and intake manifold. If you're using an Edelbrock carburetor, it's air cleaner mounting surface is about 1/8" higher than the Holley, so you'll need less spacer. Fortunately, there's plenty of hood clearance for spacers.

If you're using a Holley center hung float bowl carburetor, like 4150 series, you will have to clock the distributor so the wire output clears the carburetor.

 

You can avoid all the clearance issues with a small cap HEI such as mentioned above.

 

If you are a purist as I am, you can upgrade your original Duraspark system to outperform HEI by simply:

1. Replacing your module with a red grommet California module
2. Replace coil with Ford square coil (1984-1997)
3. Bypass or delete resistor wire that feeds coil +

This system will retard advance when starting, adjust dwell under load, provide a very hot spark all while maintain stock appearance
I managed to do this spending only $30.


There are other small reasons why I prefer this to the GM ignition such as Ford distributor caps provision for an air vent which reduces cross fire/miss fire due to ionization of air inside cap. Also, Ford uses a much taller rotor which also helps prevent misfire and degradation of cap. Also GM put the module 1.5 inches away from the high secondary voltage of the coil, --one spark to ground through the module and you're walking home.

Nevertheless, HEI is still good, but this is better!

 

There's a lot of good info here, thank you everyone for your input/suggestions.

My plan at this point is going to be:
1. Try to test the Magnetic pickup coil to determine good or bad
2. If bad, replace magnetic pickup coil (Stator)
3. If that doesn't fix the problem, consider ordering the small cap HEI kit from CRT

It may be a few weeks before I get time to spend with the truck but I will be sure to update this thread with results