No Spark at Coil

[TruDaddy]

Okay fellow boaters I have another issue. My boat in question is a s follows:

1989 Sea Ray BR200
Merc 4.3LX Thunderbolt IV V6

I have had intermittent issues with the boat dieing while running. The issue always presented itself as no spark coming off wire from coil. I did utilize this troubleshoot but am stuck on few things.

http://forums.iboats.com/attachment.php?attachmentid=131166&stc=1&d=1328016740

1. I have 12v at the pos on coil
2. The white/red wire that goes to distributor goes to the inside of the cap. DO I REMOVE THE CAP FOR THOSE TESTS?
3. Same for the Spark Gap Tester test...Do I need to remove the distributor cap?
4. I did buy a new coil. I put it in and it fired right up. Then it died after 5 fins and had no spark off the new coil. I came back 15 mins later and it fired up and ran for hours of tubing. Even refilled the tank once. The next day I came out and I get nothing from the coil.

Thoughts?

 

[TruDaddy]

Update:

I did test white/red wire that goes to distributor...12V

I also bought a new coil wire just in case ($4). I do not understand the diagnostic test for using the gap tester. Can someone point me to a video or explaing a little better with a diagram. I am trying that one but don't know if I am doing it right.

 

[TruDaddy]

Another update...

The coil I installed yesterday does not appear to pass the bench. I get 1.5ish ohms on primary winding and when testing the secondary I get absolutely nothing just the old "OL" on the meter. This is strange but not surprising. Also, does the coil require and external resistor or no? This is a debate that seems to be had with the Thunderbolt..

 

[TruDaddy]

Is anyone helping out these days? Two days ago did the full diagnosis based upon troubleshoot guide. It suggests the ignition module is shot. They don't make them so I have tried to find a reasonable locally.I went to the boat today (it is floating at a pier) and on a whim fired her right up. I have not yet replaced the ignition module. I did the tests via the troubleshoot sheet and get A okay on everything. Is it possible something else is causing this problem?

 

[gm280]

TruDaddy, I can't help but think you are fighting an intermittent electrical connection. And with that stated, start removing and cleaning wire connections to shiny metal and reinstall. And keep doing that until you have them all cleaned. And that includes the wires at the battery as well as at the engine. Especially the ground wire at the engine. As for the spark tester, usually what you do is remove a spark plug wire and install the spark tester between the removed wire and ground and crank the engine. You should see a 7/16" spark jump that gap setting. If it does, move to the next park plug wire and duplicate the effort until all are tested. If you get one or more that doesn't jump with a good spark and snap, you have a weak setup and need to fined out why. It really isn't so much of a distributor tester but a spark tester... Hope that helps out a little. Post back with your results after cleaning and testing. :thumb:

 

[Bondo]

Is anyone helping out these days?

Ayuh,.... It's Summer time,.... Those of Us that post answers have boats, 'n personal Lives to ya know,.....

I agree with GM280,..... Sounds like corroded wirin' connections somewhere, probably on the ground side,....

 

[TruDaddy]

I understand Bondo. Just the frustration of not being on the water. Well, I believe I found it. The shift interrupter switch was being triggered by improperly adjusted shift cables. I followed the directions to adjust and they definitely were out of whack. See I replaced the cables a couple of years ago. They were replaced by someone "that knows boats" Yeah right. I fixed the poorly adjusted cables and sure enough it appears to be good to go. Also, as a measure of good maintenance I did clean and tighten all wires.