My 53 has a 72 350. Twice now it has not wanted to start. Not getting fire to the plugs. The first time my son-in-law finally tapped the top of the distributer and it turned over. Figured the ignition coil in the distributer was going bad. Replaced it with one I had on hand. Has ran fine for a couple of months. Today it did not want to start so I tapped the top of the distributer it started. What the heck is going on?

 

The HEI coils have a sort of button to connect the coil output to the rotor, at least that's my recollection. Sounds like a bad connection there.

 

check ground on the coil and connections on the module. The things I've seen go wrong on an HEI, no heat grease under the module made the module overheat, no ground strap under coil made several coils go bad, the magnetic field on the pickup coil gets weak and causes drivability issues (mainly when warm).......

 

1972 should not be HEI, unless someone converted it. So is it an HEI dist? You also said that it was not getting spark to the plugs, you tapped the dist. and it turned over, turned over or started? Just trying to make it as clear as mud to help you out best as we can.

 

It has been converted to HEI. It starts after tapping the distributer. Where exactly does the grease go?

 

The grease he is talking about is a dialectric heat sink grease that goes between the module and the mounting plate, it fills the gap between the plate and the module so that heat in the module can pass to the plate to help keep the module cool. That is an issue if your truck wont start when hot and or dies when hot but runs fine while cool. I agree with the other that it is wiring issue, either bad connection or poor ground.

 

seems like I also remember a magnetic pickup under the module plate... had one that had a loose coil on it's mount and it would back away some... tapping would jar it back in place.... the the pickup coil inside the distributor... if it's loose on it's mount...replace it..

john

 

my NAPA can run a diagnostic on the ECM. Easy enough to do and maybe worth the effort to rule that out. The last one I took in the counter guy said he runs them several times. Sometimes they pass when cool but fail when they heat up and only way to check that is run it thru the diagnostic test several times.

 

it's trying to tell you it's not up too the task of pulling a real vehicle around , and wants you to replace it soon with a ford ......... most of the hei's i had in dirt track and some street cars i have had , all had that infernal dain ignition control module and worn out sloppy plug ends on the wiring have been the biggest issues , besides the fact that any gm product usually blows up under me ...........

 

If I had the money right now I would replace it. Then that would bring up the question with which one. All my street rod buddies around here tell me to stick with the chevy. I use to own a 54 which I put in a 351 windsor did not have this many issues that I have had with the chevy.

 

I agree with replacing it. No offense to anyone just a Ford guy. Maybe you can find someone that will trade engines with you. Sorry I can't help with the problem haven't had anything like that happen to me.

 

I had a SBC with HEI in another project. It was giving me fits too. Turned out to be a small crack in the cap and it was sparking out against the firewall. Might be worth a look.

 

I would say that old FORD truck is trying to tell you someting, wish you didn't live so far away, I have a 1972 351C that would fit right in there!