I've been chasing a problem with my 59AB fouling # 8 spark plug. I did some investigating tonight and actually found half the cylinders had very weak spark, it just plain runs crummy. I pulled the cap and discovered this: cap is full of shavings. Most terminals have groves cut into them AND have a burn point in the plastic just in front of the terminal (you can see the burn in the 3rd pic on the right side terminal). So what causes this? Timing? Faulty parts? The cap/rotor are Standard brand and US made. Bubba a did the distributor and the shaft feels pretty tight, don't think it is sloppy.
On mine, the cap is a very tight fit and will pull in on one side only unless I'm careful. It's got to be seated fully against the distributor before snapping on the clips. You're probably going to want to replace that cap and rotor and try again.
Just a shot in the dark, but it could be excessive cam thrust or end play which will affect the distributor's end play, chew into the crab's contact points, and cause some bad timing issues. A worn cam gear could do it also.
it looks to me and i have seen it before, that the problem is a defective aftermarket rotor. i always center the rotor in the cap and see if the rotor contact hits the cap contacts. if it does i file the rotor contact so it just misses the cap contacts and that should solve your problem. this is something that we never had to check years ago but like everything else today that seems to be the way it is now.
http://www.fordbarn.com/forum/showthread.php?t=131566&highlight=crab+dizzy+rotor&showall=1 i would agree with tommy, had the same problem myself, actually snapped the rotor in two pieces. Al.
When Bubba rebuilt my crab distributor a couple years ago he said the new rotors are a bit long, so he grinds a little from the tip for more clearance. Maybe he forgot on yours?
Good info, thanks guys! Alchemy, I did not get a cap/rotor with my distributor, I purchased them seperate from a parts house.
Just a Newtonian rotor trying to make it in a Quantum environment...sad. Rules: Don't trust any parts you buy without thorough check. Unless you personally bought them at a Ford parts counter before 1960. If something works, do not trust it to fit if you change anything around it. The good old days of buying a new part and expecting it to fit and function are officially over. Thrust can be a problem if a washer or two got lost during ***embly, but this distributor came from a good home. Crabs and 59A caps came with a variety of gaskets but they are generally useless with non-original Ford caps because their seat areas have been left out. I wonder if Drake corrected this...he understands a great deal more than most suppliers.
I use a gasket with the Drake caps. I also think the contacts in his caps are more concentric than other brands. I have them on a stock crab & two H&C's, all with gaskets.
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