Distributor cap exploded

[mckeig]

Driving home from work I heard a loud pop, then I was coasting on a 5 lane freeway. Under the hood I found the distributor cap blown in pieces. After investigation, it looks like someone put a non-spec spring in there which failed, causing the thing to burst. Not knowing much about distributors, I don't know if a new cap and rotor would fix it or not. The spring in question seems to be attached to the distributor, not the rotor. The photos are posted below. Does anyone have experience replacing these parts?

Thanks,
Chad
It's a 1980 Spider 2000, FI

http://i1059.photobucket.com/albums/t43 ... G_0538.jpg
http://i1059.photobucket.com/albums/t43 ... G_0539.jpg
http://i1059.photobucket.com/albums/t43 ... G_0540.jpg

[fiat218]

Driving home from work I heard a loud pop, then I was coasting on a 5 lane freeway. Under the hood I found the distributor cap blown in pieces. After investigation, it looks like someone put a non-spec spring in there which failed, causing the thing to burst. Not knowing much about distributors, I don't know if a new cap and rotor would fix it or not. The spring in question seems to be attached to the distributor, not the rotor. The photos are posted below. Does anyone have experience replacing these parts?

Thanks,
Chad
It's a 1980 Spider 2000, FI

http://i1059.photobucket.com/albums/t43 ... G_0538.jpg
http://i1059.photobucket.com/albums/t43 ... G_0539.jpg
http://i1059.photobucket.com/albums/t43 ... G_0540.jpg

I can send u a distributor, mine blew apart,cause from a strip screw holding the rotor in,I don't think the screw insert part is stripped . But anyways I am swapping the unit for so cal mark ignition system, u are welcome to just have it at shipping cost, no cap or rotor on it, u need the round rotor and deep cap! Mine from a 79

[bobplyler]

That spring is what controls the weights that control the distributor advance as the engine speeds up. Without the spring, the weight hit the distributor cap with a lot of force. I think just replacing the spring and distributor cap should be all that's needed, unless there are large parts of the distributor cap in the distributor. Small parts that don't interfere with the rotation of the distributor shaft shouldn't be a problem. I'd just replace the spring and cap and see what happens.

[GeorgeT]

This brings up a question: Where are the correct springs available?

[mckeig]

Thanks for the suggestions. I found a spring set at an online retailer. I'll let you know if it all works out.

[So Cal Mark]

the weights are limited in movement, but not by the springs. Exploded caps are pretty common with the Marelli units and I believe the replacement caps are not very precise in their fitment.

[CajunMike]

I had one explode on me. Just picked up a new cap and rotor and was on my way. After that I kept a spare in the trunk.

[mckeig]

I got the cap and rotor today, and the springs. The springs are the wrong size, so I just made some adjustments to the one that had come off and it seemed to go back on fine. Started right up and purred like a kitten. Glad it was an inexpensive fix.

[spider2081]

I believe Mark is correct. I have had two new cap/rotor combinations where the rotor actually strikes the posts in the cap and wears a grove making lots of metal dust in the distributor. At first I thought the distributor was at fault but a third set and the clearance is good not contact. So I would run engine and then inspect the cap after replacement to be sure rotor is not striking posts.

[ga.spyder]

We had one explode in a Lemons race.I have noticed,as Mark said,that the fit is different with certain caps.Glad it was a simple fix.Those are my favorites!

[natalburga78]

Hello again,
would you be able to tell me where did you get the distributor springs from? I checked mine yesterday and they seem to be very loose. I would hate to see my car broken on the road again. The coil died yesterday at a gas station and I had to tow so I am putting a new one today or tomorrow, but I want to replace the springs as well . Thanks
LUIS

[ChrisSRT]

check to make sure there is no lateral play in the shaft. if there is it can cause the rotor to hit the cap also.

[mckeig]

would you be able to tell me where did you get the distributor springs from?
LUIS

I got the spring set from Vick Auto. (SKU 21-5668)

[jimmycakes401]

Does anyone have a suggestion for a cap and rotor? Maybe a brand that is less prone to explosion? Mine blew apart yesterday. And my rotor blew into a million pieces too. Luckily I was just warming her up in the garage.