Spark jumping on coil

[idahoelk]

I just put my 1994 5.7 mercruiser back together (http://forums.iboats.com/showthread.php?t=559261) and it is running well except for this MAJOR issue. Once we got the timing adjusted and the distributor aligned correctly, the engine fires right up, better than since i have owned the boat (5 yrs).

However, as soon as it starts there is a loud clicking sound. I finally found it after about 5 minutes of running the engine. I have a spark jumping from the center wire on my coil to one of the side terminals. I have pulled the boot off the coil center and adjusted it, the spark still is there reaching across to the side terminal.

I know this is a mjaor issue as if I continue to operate it this way there will be an explosion at some point.

What would cause the coil to spark to itself?

Will I have to replace the coil or can i just replace the coil to distributor wire with a new one?

Thanks.

 

[Don S]

Re: Spark jumping on coil

You could have a crack in the coil tower. Usually happens if you have a faulty cap, rotor, plug wire, or spark plug that doesn't fire for whatever reason.

 

[idahoelk]

Re: Spark jumping on coil

Don,

How would I go about identifying the cause if it is a cracked coil tower? I don't want to replace it and have it happen again. When I first was trying to time the motor today, I found the wires on #4 & #6 cylinders were mixed up.:facepalm: Would trying to start it with the plug wires in the wrong order cause this?

As I mentioned previously the engine runs well, just has this sparking issue at the coil. I'm pushing $1500 already on this motor this summer and want it to run well, but the money well is getting dry

Thanks.