So my car was running rough, no codes and I figured that it was probably time to change spark plugs and dizzy cap/rotor since that's what happened last time it was running rough. Sure enough the cap and rotor was badly corroded as well as the center contact of the HEI coil. I bought an MSD 8416 cap and rotor which was supposed to be an exact fit for my 1986.




Well I got it and it isn't held down with screws or bolts but spring loaded clamps. It forces you to advance or retard the timing ~ 10-15 degrees because the clips do not line up with the flanges on the dizzy.

I put it on anyway and tried to advance the timing. ;(


PS- Returned the POS MSD cludge and got a refund. It so happens that I had a Duralast cap on there before and I had kept the box so I returned that for new one free.

I got it all back together and the dizzy in the approximate position it was before and with the EST disconnected the thing won't start. Now I'm at a loss and kicking myself for adjusting the timing when I should have returned the POS MSD cap when I saw the latch system and just left it alone.

1st problem: Can't see the timing mark on the motor with my timing light. So I made an educated guess where the dizzy should be and put it there. Engine runs but coughs and sputters when I gave it gas.

2nd try moving the dizzy and with the EST disconnected engine runs smoothe and I can rev it without misses. So I reconnected the EST and disconnected the battery. Started again and it runs horribly. Pops and coughs when revved.


Is it possible that my EST was at fault all along?

Thoughts

 

I had the problem with coughing ,popping after adjusting my timing before. Nothing was wrong, I just tried to adjust it. A close reference is to have #1 plug wire at dizzy at 5 oclock. That should put your timing mark in range. Now mine I forgot to disconnect the advance and it ran terrible. I had to try a few times starting, driving to get it to be right.
Try setting things and disconnect battery to reset everything.

 

I returned the POS MSD cludge and got a refund. Also the old dizzy cap had a lifetime warranty so I just took it back and got another one this afternoon.
After double checking firing order I found they were bass-akwards IAW the bottom of the wire cover and your suggestion.

Once sorted, it started but ran rough. Was able to see the timing light and marks and it was at 0 degrees ... ADJUSTED to 6 degrees BTDC ... and it ran as well as it did when I started which is bad. So it wasn't my dizzy cover after all. Got fire on all 8 plugs so I'm hoping for fouled plug somewhere ... next.

 

Check this video out I was sloppy with my grease and having misfires because of it.
I had to clean everything up and found a few boots weren't clicked on fully.
.

 

So to make a long story short ... the original problem was caused by fouled plugs likely caused by weak spark from the corroded dizzy cap. All better now .... thanks!




How they came out LF on the bottom RF on top