1989 4.3l merc. ignition question

[wizardmax]

i have the thunderbolt IV ignition. non points distributor, module mounted on left side exhaust, which coil do i use to replace mine. internally resisted or externally resisted. i have searched and found replies both ways

 

[Don S]

Re: 1989 4.3l merc. ignition question

Externally resisted. You DO NOT want lowered voltage to the distributor. Get the right coil for your engine, you will be a lot better off.

Why are you replace the coil, no spark?? Changing the coil is what usually happens first, then the troubleshooting starts in order to find out what the problem is since the coil didn't fix it.

 

[wizardmax]

Re: 1989 4.3l merc. ignition question

the coil was missing when i purchased boat. i have an externally resisted coil from local auto parts store. do i need to add a resistor or is it contained within a factory wire or in the module? also a side thought what is your thoughts on using a complete fresh rebuild 4.3l from an 89 chevy truck. all marine parts bolted to longblock. truck cam not marine cam?

 

[Don S]

Re: 1989 4.3l merc. ignition question

i have an externally resisted coil from local auto parts store. do i need to add a resistor or is it contained within a factory wire or in the module?

Did I not say it clear enough in my other reply?

Externally resisted. You DO NOT want lowered voltage to the distributor.

 

[wizardmax]

Re: 1989 4.3l merc. ignition question

sorry for the confusion. i understand the coil need not be internally resisted. i was unclear if that meant there is a resistor elsewhere or none at all.

 

[slicksboat]

Re: 1989 4.3l merc. ignition question

spark has a long way to go to get to plugs so none