HELP. 4.3 NO SPARK - I have tried "everything".

incrediblened

Petty Officer 2nd Class
Joined
Apr 24, 2009
Messages
148
I've got no spark from a Mercruiser 4.3 V6, Thunderbolt, 1992 Maxum.

I ran through the diagnostics in the manual. Here's what I find.
  • I've got 12v at Positive Coil Terminal
  • I've got no spark on the Spark Gapped hi-tension lead to coil when I strike the WHT/GRN lead on the ground.
  • I have tried a half a dozen working coils. (The latest was off of a 4.3 with thunderbolt).
  • I tried a distributor off of a working engine.
  • I tried an alternate Ignition Amplifier pulled from a working engine. Still NO Spark.
d.

I'm only reading 10v at my battery. Would this make a difference?

I'm about ready to take it back to a regular V6 distributor with points. I've been really struggling on this one. I would take all the help I could get.

Thanks,
:confused:Ryan:confused:
 

incrediblened

Petty Officer 2nd Class
Joined
Apr 24, 2009
Messages
148
Re: HELP. 4.3 NO SPARK - I have tried "everything".

I'm also suspicious that I've got a couple of wires that I don't see homes for.

1) Tan Wire, Starboard Top of Engine - In same bundle as white/blue wire that goes to thermostat.

2) White/Blue wire, Port Rear of Engine - kinda in the same area as distributor to Voltage Amplifier wires.

Maybe this is the culprit to my spark problem???
 

incrediblened

Petty Officer 2nd Class
Joined
Apr 24, 2009
Messages
148
Re: HELP. 4.3 NO SPARK - I have tried "everything".

HEY EVERYONE! I FIGRUED IT OUT. (no thanks to the manual. :rolleyes:). It was the shift interrupt switch. It was grounding out and preventing me from getting a spark. (Actually, my young mechanic friends accidentally smashed the wire behind the throttle bolt - grounding it to the block).

HOPE THIS HELPS SOMEONE SOMEDAY... IT REALLY SHOULD BE ADDED TO THE MANUAL. I'LL EDIT IT. :)
 

Hansolo99

Petty Officer 1st Class
Joined
Jun 27, 2009
Messages
302
Re: HELP. 4.3 NO SPARK - I have tried "everything".

GOOD FIND! Thanks for the update, this will be good for those with similar problems. Now go ENJOY the water!!
 
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