Exploding distributor cap!
Thread Starter
Melting Slicks
Joined: Dec 1999
Posts: 2,157
Likes: 0
From: Pensacola FLA
Exploding distributor cap!
While taking a few hot laps around the 1/2 mile asphalt track, my car popped and shutdown. I heard the sounds of pieces falling from under the car. Upon further inspection I found a huge hunk blown out of the distributor cap and the rotary button was in pieces! After cleaning out the distributor and replacing the broken parts, the motor fired right up and I went on my merry way. Has this happened to anybody else?
Burning Brakes
Joined: Oct 2001
Posts: 1,185
Likes: 0
From: New Wilmington PA
Re: Exploding distributor cap! (68rdstr)
I have heard of that happening.
On that particular car, the vacuum advance can was broken. Every time the guy tried to start it the cap blew up from gas fumes. This only happened a couple times before he figured it out and replaced the can.
You symptoms are different so I don't know how much help this is but it wouldn't hurt to make sure the advance can isn't leaking.
Good luck and keep us informed! :cheers:
On that particular car, the vacuum advance can was broken. Every time the guy tried to start it the cap blew up from gas fumes. This only happened a couple times before he figured it out and replaced the can.
You symptoms are different so I don't know how much help this is but it wouldn't hurt to make sure the advance can isn't leaking.
Good luck and keep us informed! :cheers:
Team Owner
Joined: May 2001
Posts: 29,745
Likes: 3
From: Exiled to Richmond, VA - Finally sold my house in Murfreesboro, TN ?? Corner of "Bumf*&k and 'You've got a purdy mouth'."
CI 6-7-8 Veteran
CI-VIII Burnout Champ
St. Jude Donor '06-'10, '13
Re: Exploding distributor cap! (Sigforty)
I have had the button that goes under the HEI coil and connects to the rotor explode and take the bottom of a cap out before. I was damn lucky the coil did not fall into the rotor.
On the outside of the cap all looked normal.
I had to put the distributor our and pull the shaft out to replace the pickup coil and clean up the mess that created.
On the outside of the cap all looked normal.
I had to put the distributor our and pull the shaft out to replace the pickup coil and clean up the mess that created.
Team Owner
Joined: Sep 2000
Posts: 65,981
Likes: 15
Re: Exploding distributor cap! (68rdstr)
I have not heard of that on Corvettes, but that is a scary situation with some older Jaguars. It is caused by gasoline fumes in the cap. The guy who owned the Jag that had that happen to him lost his car in a engine fire. He shut off the car briefly and when he started it again -- Whoomf. Fire! He then raised the hood without having a fire extinguisher. Lots of oxygen and the car was destroyed.
Melting Slicks
Joined: May 2001
Posts: 2,131
Likes: 4
From: May help you? You can sure as hell try!
Re: Exploding distributor cap! (68rdstr)
I was running an Accel dual point distributor in my '69 Z-28 and one of the posts that holds the advance springs pulled out. The post and the loose spring ground themselves into the body of the distributor and metal shavings were everwhere. I didn't know what had happened until I got the car home. The accel distibutors have the advance mechanism under the plate that holds the points. I just knew that the car was really down on power. I had a friend braze the posts in when I rebuilt the distributor so that it wouldn't happen again. I was surprized that they just pressed the posts in place when they made the thing. Otherwise I thought it was a very well constructed distributor.
You're lucky you were able to get home without too much trouble.
You're lucky you were able to get home without too much trouble.
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
Re: Exploding distributor cap! (Cookwithvette)
So how about 1 part fuel to 14 parts air and add bunch of small sparks. Ah! Well-roasted distributor cap. Okay thanks Chiefy, I got it. :jester
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Thread Starter
Melting Slicks
Joined: Dec 1999
Posts: 2,157
Likes: 0
From: Pensacola FLA
Re: Exploding distributor cap! (Dep)
It looks to me that the cause was due to the Accel rotary button coming apart for some reason. Maybe one of the holding screws backed out. I found half the button still attached and the rest along with the other holding screw inside the distributor. The car was running great prior to this happening as I had just got back from the annual Corvette car club show "Lifes a Vette on the Beach". I'm glad the problem popped up at the track and not on the highway:bb Maybe the car was pissed off at having to turn left all the time:D
I replaced the cap and rotary button with the Autozone brand and the car is back to running great again.
Mike, thanks for the compliment. You also have a great looking 79! :chevy
[Modified by 68rdstr, 7:07 AM 10/25/2003]
[Modified by 68rdstr, 7:10 AM 10/25/2003]
I replaced the cap and rotary button with the Autozone brand and the car is back to running great again.
Mike, thanks for the compliment. You also have a great looking 79! :chevy
[Modified by 68rdstr, 7:07 AM 10/25/2003]
[Modified by 68rdstr, 7:10 AM 10/25/2003]
Le Mans Master
Joined: Oct 2002
Posts: 5,714
Likes: 6
From: Silver City NM
St. Jude Donor '05-'07
Re: Exploding distributor cap! (68rdstr)
That's kinda surprising that a cap designed for high performance would have a catastrophic failure like that. I'm not disputing your findings, but maybe you should contact Accel and let them know what happenned? If it's a factory flaw or defect they would probably address it and/or even give you a new cap. As it is I think I'll use Mallory parts on mine.
Dep
[Modified by Dep, 1:03 PM 10/25/2003]
Dep
[Modified by Dep, 1:03 PM 10/25/2003]
Melting Slicks
Joined: Jun 2002
Posts: 2,842
Likes: 99
From: Orrtanna Pa.
Re: Exploding distributor cap! (Dep)
When I pulled the 355 out the engine had 120,000 miles on it,and I'd never changed the cap in all that time because to be honest the car ran great and I was too lazy.The cap had a huge hole where the rotor button used to be,and I couldn't even find the button or spring.There was no explosion,but it beats the heck out of me how the engine could even run,much less run as well as it did. :crazy:
Le Mans Master
Joined: Apr 2000
Posts: 7,562
Likes: 9
From: B'Ville NY
Cruise-In III Veteran
St. Jude Donor '05
Re: Exploding distributor cap! (The Money Pit)
This same exact thing happened to my friend at Watkins Glen during a Vintage Car race at about 125mph in a corner with others all around him. He said the car just died suddenly, when we popped the hood, we found the dist cap in pieces. We figure either the cap wasn't vented (performance caps come with holes in them for ventilation), or his rotor had a screw back out to allow the rotor to become free and destroy the cap ;) .
Check your timing, it can change when changing the cap & rotor.
BTW, Nice car !!! :cheers:
Check your timing, it can change when changing the cap & rotor.
BTW, Nice car !!! :cheers:
Thread Starter
Melting Slicks
Joined: Dec 1999
Posts: 2,157
Likes: 0
From: Pensacola FLA
Re: Exploding distributor cap! (SmokedTires)
I'm going with the screw backing out of the rotary button is what caused the mayhem. Maybe it was my fault and I didn't tighten the one screw properly.
I've since put a dab of loc-tite on the new rotary button screws and made sure they are tight. Hopefully this doesn't happen again.
SmokedTires, thanks for the tip on the timing I'll have to check it out and your car is sweet!
Thanks all! Bryan
:chevy
I've since put a dab of loc-tite on the new rotary button screws and made sure they are tight. Hopefully this doesn't happen again.
SmokedTires, thanks for the tip on the timing I'll have to check it out and your car is sweet!
Thanks all! Bryan
:chevy
Intermediate
Joined: Mar 2003
Posts: 49
Likes: 0
From: flomaton al
Re: Exploding distributor cap! (68rdstr)
When I first got my car it had a mallory distributor, It ran very well until one day at about 5 mph the whole thing came apart didn't knock the cap off but it destroyed the baseplate and rotor button I assume the screws backed out. I put another distributor on it and the car ran fine.
Le Mans Master
Joined: Oct 2002
Posts: 5,714
Likes: 6
From: Silver City NM
St. Jude Donor '05-'07
Re: Exploding distributor cap! (white74)
All you guys that are having problems witn name brand parts...send them to the manufacturer!!!! Can't hurt and you may get a free one or refund in exchange. At the very least they will find out what failed and correct it in future models.
Dep
Dep
