Well, here I go again. The car: 89 Camaro IROC-Z L98


Ignition mods: MSD Digital 6 plus, Accel Supercoil, MSD 8366 Pro-billet
distributor, new GM Delco ignition module, 8.5mm plugwires, NGK p/n 3951
plugs, and a new 3-4 month old MSD Pickup coil (burned up the last one)

What would cause accelerated cap/rotor wear, and possibly another p/u coil?

Car wouldn't start again today, starter(TJ Jr. ministarter) was cranking
good and strong and battery is good (Optima). Symptoms are all the same as
before, idle gets bad/choppy after a little while, then cranking starts
taking longer and longer until one day it won't start.

In order to remedy the problem I've even drilled 2 holes in the distributor
cap about rotor height to vent the ionized air out of it...that buys me
about a month or 2.
All I can think is that the Accel coil may be too hot for the car? I'm
thinking to replace the cap/rotor, ohm the p/u coil leads to make sure it is
good, remove the Accel coil and put the stock dual connector coil back on.
We'll see how that works out.

Has anyone ever dealt with a problem like this? On the GMECM List not long
ago I read about the wear of the small cap HEI...Bruce Plecan stated that he
used lots of dialectric grease.

Thanks guys,

Brian P

 

You could do what the factory did on the LT1 distributors. Those OptiSpark distrtibutors produced after 1993 had a filtered air supply tube from the intake bellows and a vacuum tube from the plenum to constantly forcec ionized air, dust, and moisture to be purged from the high-voltage side of the distributor.

You could fashion a similar apparatus as a "band-aid" fix, but chances are the distributor cap is physically too small and lacks adequate physical separation of the individual terminals to effectively insulate them from one another after a little exposure to ozone. A lot of voltage will create a lot of ozone, and a little of that goes a long way toward breaking down the plastic and conducting power all over the inside of the distributor. Perhaps a larger distributor cap, like what Ford was using on large V-8s in later years, would provide adequate isolation of the terminals.

 

Have you called/emailed MSD ( http://www.msdignition.com ) about it? Maybe they can hook you up with a new pickup coil. Is everything else good (like ignition timing, spark plug gap/heat range, etc)? And I assume you used the silicone grease on the new spark module For kicks, you might want to see what my MSD 6AL and Blaster SS coil did to a stock (and brand new!) AC/Delco cap & rotor - http://www.geocities.com/tomp_3rdgen/burnt-cap.html

 

I am having the same issues as you are, only with a regular cheap cap and rotor from Autozone. Just a plain run of the mill coil in cap setup.

With a new cap the car runs like a champ then progressively gets worse until the cap is toast and the car won't start.

This is a very frustrating and crazy problem, let me know if you find a solution.

 

Yes I had the same problem....I was a long shot but it paid off for me!
.....If the reluctor and pickup magnet don't line up when the rotor is pointed at a post, the spark will occure before or after the post, creating a LONG Spark from the tip of the rotor to the post. This causes accessive heat and spark inside the cap and puts a strain on the ignition system. If you want to check this problem, ...remove the cap:
....cut about a 1" hole or slot in the cap at the #1 post so you can see the rotor.
....Highlite the rotor with a paint marker or somthing to make it easier to see
....Start the engine, give a little RPM and shine the timing light at the slot.
The rotor shold be firing on the post...if not then thats the problem!