Hi guys,

Ran into a strange problem... Was doing some tuning yesterday, pulled into driveway and vehicle stalls, wont restart.

I check and I have no spark. So off comes the distributor cap and inside the rotor top is what looks like melted parts, blown to hell. The center post in the cap is just a black burnt hole now. The posts in the cap also show significant build up (More buildup in 500 miles then I see in an old cap)

I'm using a MSD Digital ignition which Im sure somehow contributed to the problem. The rotor and cap are both new with about 500 miles on then. They went in when I put in the MSD.

Is this just a defective cap? Or am I going to be replacing caps every 500 miles.



Eric

 

Well isn't that special!

This a "trend"... Everything I buy has problems with it lately. Some things don't work right out of the box and I need to return it or fix it to get it to work right.

So now I guess we are going to have these problems with auto parts as well?

Arrgggg!

 

This is a common problem when running MSD and stock HEI caps/rotor buttons.

Fix:

1) get a low resistance HEI rotor button from MSD.
2) get an alkyd cap and rotor.
3) install the new rotor and cut a window in your OLD cap so you can measure the rotor tip to cap contact gap.
4) report back with the gap.

 

Thx for the reply. Turns out the damage extended beyond the cap.

The MSD Coil is toast. It buzzes out ok with a meter but it wont fire on the vehicle now. I took out the MSD completely, and put in my old OEM coil until I can figure out what happened. Put a new cheapy cap/rotor on for now.

I did try the MSD with the new Cap/roto/old coil. I could hear a high frequency noise in the cap I dont recall hearing before. So I took it out of the loop again. I went ahead and replaced the ignition module in the distributor also since I had a new one on the shelf.

So I guess I'll be shopping for a higher quality cap/rotor and another MSD coil. Then pray that the failure didn't originate at the MSD unit.

If I get a chance Ill measure that gap..

Thx the help guys
Eric

 

Definately go with a higher quality cap and rotor, I had the same thing happen when I first got my bird. Did the manditory tuneup and found a hole burnt clear through the coil post, post was gone just the wire stuck throught the hole, ironicly it still purred like a kitten. All stock at the time too. I'd still do as diy-efi recommended and cut the window in the old cap and see what kind of gap there is