Ever since I have had the car I have been plagued with stumble/hesitation issues. I had always thought this was due to the carb, however it may have been the distributor all along.
I had noticed on hot days (hot for Ireland) that the car would hesitate on hard acceleration. I changed fuel pumps, fuel lines, filters and even the carburettor (twice!) but the problem was still there. It turns out it may have been the condensor in the distributor cap all along.
When I first got the car I ordered a basic electronic ignition kit so I decided to see if that would make a difference. Basically the points and condensor are removed from the distributor and a magnetic ‘wheel’ is put in it’s place. Critically, you are meant to disconnect to the vacuum advance (cue my next issue). The car ran perfectly with this new set up and I was very pleased with myself. I took it for a drive, gave it some gas and it spluttered an died (right on an uphill corner…). I was able to get it started after a couple of minutes but under acceleration it would splutter and 2 minutes up the road I coasted into a siding. Taking off the dizzy cap I could see that the new ‘wheel’ was chewed up….caused by the vacuum advance still being connected causing contact with the main shaft….stupid me!
Earlier in 2025 I had purchased an HEI distributor but when I went to install it I found that the originaly distributor was well and truely stuck, so decided to leave it alone.
Due to the latest issue I decided to work on this again and add the HEI.
This was prepping the distributor for the electronic ignition module. Out with the points and condensor.
New kit in..and minutes from destruction. It ran fine but I made a rookie error and didn’t read the instructions properly and left the vacuum advance in place. This damaged the ‘wheel’ around the shaft.
After deciding to replace the distributor I really had to get after it with a hammer and pry bar to get it out. The entire top of the distributor was destroyed and I was very lucky it all came out in one piece. You can see that it had pretty much welded itself to the block with rust. I was also lucky the the oil pump shaft wasn’t damaged but at least it was out!
Once the opd distributor was out I moved on to finding TDC (top dead centre) using the old school method of placing a screwdriver in the spark plug hole of cylinder 1 and rotating the engine until the screwdriver was at its highest. Then I popped in the HEI distributor, connected the HT leads and wired it up. The good thing was that I no longer needed a separate coil so out that came as well.
I cautiously fired it up and to my delight it ran really smoothly. Much smoother than it had for a long time. Oil pressure was fine as well so I knew the oil pump shaft was correctly seated in the distributor. Happy days and job done!
My Mustang Journey 