Coil pack testing question

switch cylinders with the wires and see what happens to your plugs

Mike Romain wrote:

> I know this coil pack isn't off a car, it is off a Johnson outboard, but
> thought maybe some of you knowledgeable folks might know how to test it.
>
> It is for my sister-in-law's boat that my wife and I get to borrow so I
> am trying to repair it for her.
>
> The engine is a 2002 9.9 hp 4 stroke Johnson, Model J10TE4ST, with a two
> cylinder coil pack. I believe the Johnson and Evinrude engine has the
> same coil.
>
> It will start and idle OK, but has no throttle response when the rpm
> come up.
>
> This coil only appears to put out one spark on one side, the top
> cylinder. The bottom cylinder doesn't fire and the plug is wet with
> gas. I put in new plugs and not a mark on it when the top one showed
> clear heat marks. I swapped the plugs, same deal. The coil wires are
> solid core and both of them and their 10K spark plug caps test OK with
> my multimeter.
>
> I have looked with google and can't seem to locate any resistance type
> of tests for this kind of coil.
>
> If anyone has any specs for it, I would sure appreciate them so I can
> troubleshoot this engine a bit more.
>
> The coil runs $130.00 and the brain box or module to run the coil costs
> about $600.00.
>
> Thanks,
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 'New' frame in the works for '08. Some Canadian Bush Trip and Build
> Photos: http://mikeromainjeeptrips.shutterfly.com

Unfortunately I have to rely on a meter, the wires are not long enough
to swap.

Mike

mr158912 wrote:
> switch cylinders with the wires and see what happens to your plugs
>
> Mike Romain wrote:
>
>> I know this coil pack isn't off a car, it is off a Johnson outboard, but
>> thought maybe some of you knowledgeable folks might know how to test it.
>>
>> It is for my sister-in-law's boat that my wife and I get to borrow so I
>> am trying to repair it for her.Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
'New' frame in the works for '08. Some Canadian Bush Trip and Build
Photos: http://mikeromainjeeptrips.shutterfly.com

>>
>> The engine is a 2002 9.9 hp 4 stroke Johnson, Model J10TE4ST, with a two
>> cylinder coil pack. I believe the Johnson and Evinrude engine has the
>> same coil.
>>
>> It will start and idle OK, but has no throttle response when the rpm
>> come up.
>>
>> This coil only appears to put out one spark on one side, the top
>> cylinder. The bottom cylinder doesn't fire and the plug is wet with
>> gas. I put in new plugs and not a mark on it when the top one showed
>> clear heat marks. I swapped the plugs, same deal. The coil wires are
>> solid core and both of them and their 10K spark plug caps test OK with
>> my multimeter.
>>
>> I have looked with google and can't seem to locate any resistance type
>> of tests for this kind of coil.
>>
>> If anyone has any specs for it, I would sure appreciate them so I can
>> troubleshoot this engine a bit more.
>>
>> The coil runs $130.00 and the brain box or module to run the coil costs
>> about $600.00.
>>
>> Thanks,
>>
>> Mike
>> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>> 'New' frame in the works for '08. Some Canadian Bush Trip and Build
>> Photos: http://mikeromainjeeptrips.shutterfly.com
>

Thanks for the ideas folks, it was a strange one.

My adult son and I went up with some diagnostic tools this time like my
timing light and digital logic probe for testing the output and input of
that coil.

I plugged it back together and started it and well... The freaking
'bottom' cylinder is now working and the top isn't... My kid is now
chuckling, figuring out fast it's back to the drawing board... So...
after carefully looking at bolt marks and a wire clip under a bolt mark
we determined that I didn't put it back together wrong so I took it all
apart and used a contact cleaner on the copper strands in the coil wire
and the screw end for the spark plug cap and put it all back together
and it purred...

Figures, your basic of basics, a bad spark plug wire connection.... that
according to the local marina just 'Never' happens. Ya right only a
coil or brain box fails, right. LOL!

This engine only has about 40 running hours on it, but sits out all season.

Mike

Mike Romain wrote:
> I know this coil pack isn't off a car, it is off a Johnson outboard, but
> thought maybe some of you knowledgeable folks might know how to test it.
>
> It is for my sister-in-law's boat that my wife and I get to borrow so I
> am trying to repair it for her.
>
> The engine is a 2002 9.9 hp 4 stroke Johnson, Model J10TE4ST, with a two
> cylinder coil pack. I believe the Johnson and Evinrude engine has the
> same coil.
>
> It will start and idle OK, but has no throttle response when the rpm
> come up.
>
> This coil only appears to put out one spark on one side, the top
> cylinder. The bottom cylinder doesn't fire and the plug is wet with
> gas. I put in new plugs and not a mark on it when the top one showed
> clear heat marks. I swapped the plugs, same deal. The coil wires are
> solid core and both of them and their 10K spark plug caps test OK with
> my multimeter.
>
> I have looked with google and can't seem to locate any resistance type
> of tests for this kind of coil.
>
> If anyone has any specs for it, I would sure appreciate them so I can
> troubleshoot this engine a bit more.
>
> The coil runs $130.00 and the brain box or module to run the coil costs
> about $600.00.
>
> Thanks,
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 'New' frame in the works for '08. Some Canadian Bush Trip and Build
> Photos: http://mikeromainjeeptrips.shutterfly.com