NEED HELP! No spark on #2

ThePvtPyle

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Jul 1, 2020
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I have a 2002 merc 40hp 4stroke that has no spark on #2 cylinder, if i put the #1 or #3 wire on the second coil it has spark.

I have changed the ecm, the stator and the wiring harness, still no spark on #2. There isnt much left to check. Does anyone have any other ideas where to look? I'm loosing my mind on this thing.
 

gm280

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Jun 26, 2011
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Have to swapping the coils around and checked? Maybe a good cleaning of the connectors and grounds would help?
 

ThePvtPyle

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Jul 1, 2020
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I have not physically switched them around but no matter what coil I plug the #2 pig tail into it will not fire any of the coils. If I plug the #1 or #3 pig tails in, they will fire all the coils no problem. Do the 4 strokes have a trigger like the 2 strokes?
 

Faztbullet

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Mar 2, 2008
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The ECM is what triggers the coils......make sure pins not bent in harness connector to ECM. Its either ECM or bad ground thru harness. It has a CPS instead of trigger
 

ThePvtPyle

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Jul 1, 2020
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I replaced the ecm and the main harness, same issue, coulld it be the CPS? And can you elaborate on what CPS stands for? I know my way around small engines, not marine thought lol.

Could it also be the hardness that comes from.the run switch? Could that ground out one coil if there is a broken wire ?
 

Faztbullet

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CPS = crankshaft position sensor and no if bad other cylinders would be acting up also.
 

ThePvtPyle

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Jul 1, 2020
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Could it be the extension harness from the tiller handle? Does the kill switch ground out each coil individually??
 

gm280

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Could it be the extension harness from the tiller handle? Does the kill switch ground out each coil individually??

Actually I personally have no idea if the "kill switch" kills the individual coils. From an economic point of view, it would seem less costly to kill the circuit feeding the coils. Less parts, less cost. But I have no verification of that either. Just my opinion knowing how companies work towards the cheapest routes for more profit...

I am watching this thread closely because it now is a mystery for me... Would love to be there in person and do my trouble-shooting routine. Things like this are interesting for sure.
 

ThePvtPyle

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Yea its a mystery that is driving me crazy lol. I have almost changed everything except the extension harness, what else is left to change? Lol
 

Faztbullet

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Mar 2, 2008
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You have the factory manual??? If so read on how ECM latches the coil and look at wiring diagram...nothing for ignition coils goes thru handle as all goes to ECM.
 

ThePvtPyle

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Jul 1, 2020
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No I don't have a manual yet. If it all goes through the ecm, I replaced the ecm, main wiring harness and stator. That should have eliminated any problem in that circuit. The only thing I can see is the tiller handle extension harness that plugs into the main harness. Am I missing anything else?
 
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