so yesterday i was hearing an arcing sound in teh engine bay of my 85 S. no big deal, i trace it to a split coil. i replace the coil and the arcing gets worse...its coming heavily from the distributor. the engine is running fine and not missing what so ever, but i decide to pull the cap and take a look to easy my temptations of finding another problem. i found this:



it crumbled to pieces and tore up the cap really bad:


i replaced both from parts i had on the shelf and the engine runs just as well. not sure what may have caused that to happen. in 10 years of owning and building RX-7's i have never seen anything like this. there's a first for everything though.

 

Ummm, whatever you did - you did it wrong LOL. Maybe it got hot and thats what caused the extra flexing of the rotor and then in turn caused the other (incredibly insane) damage.
Edit: I cant even begin to understand how your engine would run correctly with the cap/rotor like that.

 

12As, you gotta love 'em. Absolutely bullet proof.

Do you have direct fire ignition? If so, you don't really need the dizzy. Check this out:

http://www.youtube.com/watch?v=kwKlbX0DSRk

 

I gotta tell you Ray. I dont understand how that works at all. I mean, what tells the coil to fire? How would you adjust timing if no distributor or CAS???

MY MIND IS ABOUT TO EXPLODE!!!!!

 

I've trashed new caps and rotors simply due to not seating the cap properly. All it takes is a bump against the cap to shift it out of place. That's the worst one I've seen to date. Another cause may be that the rotor wasn't fully seated.

 

Im almost willing to bet that a chunk of the rotor came off and that caused all that havoc in there. Stupid trailing arms of the rotor...

 

AHHHHHHHHHHHHHHHHHHHHH


BANG!!!

*is dead

 

Wow. I've never seen that before. And, I'm with Ian, how is that even possible on the dizzy cap, Ray?

 

When you have the 2nd leading coil firing the leading plugs you can remove the cap and rotor and run the engine with no problem. You don't need them to run the engine with the 2nd gen coil firing the main plugs.

 

A while back, I was driving down the road at night, heading home when I hear a loud POW from the engine compartment. All the dummy lights lit up. I pull over, and see that the alternator belt snapped. Pulled the belt out and drove home (Thanks Yoohoo Belt!). Replaced the belt but had a popping sound.

Took off the dizzy cap, and lookit!




Turns out that when the belt snapped (misaligned alternator bracket, bent it back a little and no more problems) it wacked the distributer cap and broke a chunk off the button

 

You are right Ian, you need the dizzy, but you don't need the cap.

 

perhaps it wasnt seated fully.. i am using a 2nd gen coil pack, lol...

 

I had the same thing happen sometime in the late 80's with my 82. I left Seattle on a trip to Eastern Washington. I was traveling along in a snow storm about 80 mile from home when the engine just died like I had turned off the key. Had no clue as to what happened, so I had the car towed clear back to Seattle to a Mazda dealer. When I called to find out the prognosis, they told me it was fine. My rotor simply flew apart. Wish I would have thought to pull the cap when it died. I would have saved a hefty towing bill!

 

maybe at some point yesterday i leaned on the cap and cocked it...i'll never know. i'm just glat it didnt come off during an autocross or a daily commute!!

 

Thanks for posting!! Give us all one more thing to check before we call a tow truck!!
Stu Aull
80 GS
Alaska

 

That's crazy dave, I've never seen a cap and rotor get killed like that, at least it was easy enough to fix...

 

Yeah, I've had that happen a couple of times over the years, and seen it happen a few more times. All it takes is a slightly misaligned cap, and the rotor will tear it up in short order. Get your **** straight, man!

 

I have seen that b4. and it sucked *****.

 

I threw a belt at the track earlier in the year... It did knock the cap slightly sideways, but luckily it didn't destroy itself on the rotor.

 

Man in Black and I drove our cars a couple hundred miles to Norther Michigan,
the middle of BFE, for a big autocross event at a closed airforce base.
After his first run, he came limping back into the pits sounding like he had blown
his motor. As it turned out, he just blew his cap/rotor apart just like you did.

Since we were in the middle of nowhere, the nearest parts store that had one
was about 80 miles away. Just as he was leaving to go get the parts, a 1st gen
drove by. He chased him down, and the guy just happened to have a couple of
extra dizzys in his storage bin.

I told him he should start playing the lottery...

 

New product: Distributor belt-deflector & elbow-rest!

That's nuts.

My wife thinks I'm crazy 'cause I don't just throw my "worn" parts away.

 

i save EVERY usable part that comes off of my 7's when i replace parts. i will even save brake pads if they're still usable. you never know when you need a spare set just to get you by a week or so.

 

My cousin and I were racing our GSL-SE one night many moons ago and his car lost traction in 2nd gear. As a result he stayed on the gas like a dumb a$$, 180 spin out and ran up a small divider but the car was fine. Car shut off and wouldn't start. Fuseable links were fine but under the cap, low and behold busted rotor. This happened around 12am, good thing he had just did a tune up and saved the old parts. Bad thing was that I had to drive a half an hour away to pick it up and come back.

 

I only buy clear distributer caps so I can SEE the power my engine is making.

 

u been smokin to much ??