My 340 Sundancer has a Kohler 5ECD generator with no spark on one cylinder.

BoatMech

New Member
Dec 27, 2014
8
Satellite Beach Florida
Boat Info
340 Sundancer 2007
Engines
8.1 Mercruiser V-drives
I have done everything in our shop to try and find the cause of the no spark on one cylinder condition. Has anyone else encountered this problem on their generator?
 
What have you done with it so far? When was its last tuneup and the last time it was run?
 
So far I have changed plugs. Swapped the coils from one side to the next. I have verified the 12 volts to the E terminal of the coil harness. I have verified the 5 volts to the A terminal. I have verified the ground connection and resistance on the B,C,D terminals. I have ohmed out the harness to verify the connections to the ECM, all good, no breaks and no shorts to ground. I completed the Kohler Service Bulletin about setting the correct valve last so that the MAP sensor can sense the piston movement and signal the ECM to fire the cylinder. Keep in mind the engine runs perfect on one cylinder under light load. It is just not signaling the number two coil to fire the spark plug. I verified compression on that cylinder. It is very good and matches the running cylinder. I verified the ohms on the crank position sensor. It is one single CPS and an indexed plate, so the CPS is common to both cylinders. I replaced the ECM, $900.00. I talked with the Kohler factory representative and he said that I have done all that he would have done and that he has no clue why the cylinder is not firing.

I am a 36 year Marine Engine Mechanic, this generator has been very well cared for. It only has 214 total hours on it and in is so clean that it look brand new.

I was hoping that someone else has encountered this very strange problem and found the fix for this situation.

Jim Johnson
 
Jim, my neighbor had the same issue last year. I will see him tomorrow down at the boats. I will ask him what he did to fix his. I know he replaced the coil and the wires. At one point he replaced the plugs and it turned out that one of the brand new plugs had a bad resistor and it was grounding itself out. I know we took the unit out of the boat and he took it home to his shop, almost completely rebuilt the thing, put it back in and it still wasn't fixed.

I will get with him when he comes down to the boats tomorrow
 
Jim, I had a set of plugs that were marked as resistor that were not cause a similar issue. Can you install old plug or swap plugs and see if the problem follows to the other cylinder?
 
Sounds like you've done a lot of analysis but I wasn't clear on the first thing I would have checked: Are you getting spark on the coil wire to the plug that isn't firing when the engine is cranking?
 
I got with the neighbor. His was the coil.

You can bench test your coil, but I don't know how it's done.
 
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There is no spark on the spark checking tool from Stevens Instruments and it does not light the timing light while the generator is running. I have swapped the known good coil to the other side and it does not spark on that side, switch it back and it works fine. Plugs have been changed and also swapped from the known good side to the other side with the same result. This problem is really throwing me a curve.

Jim
 
There is no spark on the spark checking tool from Stevens Instruments and it does not light the timing light while the generator is running. I have swapped the known good coil to the other side and it does not spark on that side, switch it back and it works fine. Plugs have been changed and also swapped from the known good side to the other side with the same result. This problem is really throwing me a curve.

Jim

Jim does your coil have two plug wires coming out of it ( one for each plug)
Also I will ask my buddy how he bench tested mine from my Wester.

If you can send me a picture of the coil it might help. Send it to my email gpw1001@aol.com
 
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Jim, I talked with Tommy he strongly suggested getting a set of pick ups as well.

He also has a warning, he had to remove the Genset to get to his pick ups out
 
Installed a new map sensor and a new crank position sensor. Still no spark on one cylinder. This model does not have individual pickup coils the spark timing is controlled through air pressure pulses picked up by the map and by the cps. I have again had no help from the Kohler people. I have new coils coming in for this thing. A new generator is $9000.00, I can replace every ignition part for around $3000. This thing has no run time on it. Since no one in the marine business including me can figure this one out, I am just going to replace parts until it works.:(

Jim
 
No spark on number one that is. Generator runs great on the one cylinder as long as there is a light load. Still smell the gas and still see it in the water discharge.
 

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