TR4/4A Sudden loss of points gap

[carpecursusII]

While driving along last night I went from perfect running to not running at all in the matter of 1000' feet of road. I removed the distributor cap to find that the points were not even opening. The screw that holds the breaker plate was not loose. Has anyone ever had this happen? What would cause such rapid failure?

 

[tomshobby]

Sometimes it can happen if the dizzy cam is not lubed. That can cause the point's contact to wear very quickly like you have described.

 

[CJD]

They likely wore slowly, but reached a critical point where they were no longer "breaking".

 

[trrdster2000]

I have seen this happen when someone put in a hot coil. The points plastic got so hot it melted and closed them up within a mile.

Wayne

 

[Andrew Mace]

I have seen this happen when someone put in a hot coil. The points plastic got so hot it melted and closed them up within a mile.

Wayne

That doesn't surprise me, as some of the currently available points sets don't ... er ... seem to be quite the quality of those from days gone by. I don't know if the older ones with the phenolic rubbing blocks were any better in that regard, though.

 

[carpecursusII]

Coil is Bosch blue, the dizzy has about 2000 miles since a full rebuilt by Jeff at AD. I understand that the follower would wear out after some time but I wouldn't think it would be that quickly.

 

[Geo Hahn]

As noted, lubing the cam will help prevent this. They used to include a little capsule of lube with the points (they also used to fill your tank, wash the windscreen and check your oil).

I use a dab of assembly lube once in awhile.

Also - important that the screw holding the points setting is tight.

 

[NutmegCT]

The points can "suddenly close" if the distributor itself slightly rotates, due to the fastening clamp bolt coming loose.

Ask me how I know ...

 

[pdplot]

I used to put a dab of wheel bearing grease on the cam to prevent wear. Works fine and won't melt.

 

[pdplot]

I used to put a dab of wheel bearing grease on the cam. helps prevent wear and won't melt away.

 

[TR4nut]

I am overdue for giving Jeff at Advanced Distributor feedback, but he rebuilt my distributor and did a great job- but the points set he used failed in about 1000 miles. In my case the point itself broke off. Not the same as you and not Jeff's fault, but a warning that parts quality can be an issue. I went back to Pertonix and have been happy for a couple years now.