[mrjestro]

1967 Firebird, 455 - MSD 6AL, MSD Pro Billet Distributor, Blaster Coil, Timing Control.

I've had my car on the road for 15+ years. Never any ignition trouble. Recently at lower RPM it has a weird intermittent stutter. Then a backfire. Only does it sporadically. I thought the rusty reluctor wheel in the distributor finally caught up with me. I called MSD tech line this morning they assure me that wouldn't cause it.

Before I pull every electrical connection and ground apart to troubleshoot any thoughts? Trying to control the urge to start replacing parts.

[Scott Stoneburg]

How old is the cap and rotor, if it sits alot the terminals inside the cap can become corroded and cause cross fire

[mrjestro]

Originally Posted by Scott Stoneburg

How old is the cap and rotor, if it sits alot the terminals inside the cap can become corroded and cause cross fire

Replaced the cap and wires late last season. Everything's been business as usual until the last couple times I've driven it.

[lucky1]

Is your cap ventilated ?
High voltage can creat ozone, which corrodes the contacts.

[mrjestro]

Originally Posted by lucky1

Is your cap ventilated ?
High voltage can creat ozone, which corrodes the contacts.

It's an MSD cap with sockets rather than pins, it has the window, not sure if that's considered ventilated?

[lucky1]

I don’t believe that cap is considered ventilated.
It has been addressed here on the forum how to drill holes to make it so, though.

[4dblnkldude]

I drill a couple 3/8 holes in the cap. They can get really bad just sitting a few months.

[Scott Stoneburg]

Originally Posted by 4dblnkldude

I drill a couple 3/8 holes in the cap. They can get really bad just sitting a few months.

Where do you drill the holes?

[Dragncar]

MSD used to sell pre drilled vented caps.

[AG]

I drill two 1/4" holes in my MSD distributor cap and have not had any issues with rotor corrosion or ignition performance.