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Posted by: jfort May 11 2008, 07:14 PM

The day finally arrived - flare project done. Picked up car Saturday. Drove the 5 mile trip home. It was running rough but it has been all winter with little running. I put in new spark plugs. Still idled rough. I would hear a crack sound while I was watching it idle. Noticed arcing from side terminal on coil to center terminal. Tried to move the car and the engine quit and it will not re-start. Bad coil? I have a new one on the way. What else could it be?

Posted by: Rusty May 11 2008, 07:19 PM

I'd check your plug wires. If they are not conducting properly - the spark will want to jump to somewhere.

I would consider cleaning your plugs, too. They are likely fouled if the spark isn't strong enough to burn all the fuel in the cylinder.

Posted by: proto31 May 12 2008, 10:15 AM

You might have fried your CDI box with all that shorting going on, that would be a good explanation as to why your car will not starts. Hope you have a spare!

Posted by: 6freak May 12 2008, 10:23 AM

QUOTE(Rusty @ May 11 2008, 06:19 PM)

Posted by: 9146986 May 12 2008, 01:30 PM

The CDI box will make a faint whine when it's on. The CDI ignition does not use a coil, it looks like one, but it isn't a coil.

Posted by: jfort May 12 2008, 02:01 PM

thanks for the responses. i can't believe it is a spark wire. they are relatively new -- the orange, expensive one. but we will check. my mechanic friend is coming out for a house call on Wed. He knows (and tried to explain to me) that it is something different from the classic coil for the CDI that I have. He has ordered a new one. I hope it is not the CDI box itself. I am hoping he has a spare so we can isolate the problem. I remember replacing one on a 911 one time and it was expensive.

Posted by: SLITS May 12 2008, 04:22 PM

Factory calls it a "transformer". Instead of being fed about 9 VDC (conventional coil with resistor), the CDI shoots about 3 - 400 Volts at it.

Posted by: 6freak May 13 2008, 09:42 AM

QUOTE(SLITS @ May 12 2008, 03:22 PM)

Posted by: jfort May 13 2008, 01:38 PM

can't work on it 'till tomorrow - Wed. My friend/mechanic is bringing CDI box, the coil/transformer and some plug wires. Hopefully we'll isolate issue. I'll let you know what happens. I sure appreciate your thoughts and input. I NEED TO GET THE CAR RUNNING.

Posted by: jfort May 20 2008, 08:49 AM

update - My mechanic brought a new Bosch transformer/coil and installed it. Still no spark. Then he noticed that the CDI box was loose. He tightened it. Car runs fine now. Must have been bad ground due to loose bolt. However, now my tach doesn't work. The arching and sparking I noticed earlier was right where the take-off is to the tach. I checked the connections at both ends. OK. The tach is grounded and getting 12v. I think it must have been damaged by the coil/CDI box issue.

Posted by: 6freak May 20 2008, 09:45 AM

QUOTE(jfort @ May 20 2008, 07:49 AM)

Posted by: Rusty May 20 2008, 09:52 AM

if the car is a factory six, there is a ballast on the relay board that you can check. It's a small silver cylinder. About 1" in diameter, 2.5" high.