99 DT140 EFI not starting, spark on syl.1 only

[Bergsholmen]

Hi.
Have a DT140 EFI that worked fine about 4-5 weeks ago.
Now trying to start its, dead.
I found spark on 1 sylinder only (syl.no 1), anyone have an idea of hva can be wrong?

Was a stort trip in the boat today, startet pulling off som parts to locate ECU and wiring. I found leads from battery charge coil (red and yellow) burned in the connections between stator and wireharness (don't now if the connection was off, just that there have been warm)
Does that have anything with starting or just charging?

[bladenbullet]

burnt connections are a sign of a poor connection...resistance creates heat and voltage drops...on ecu equipped engines it doesn't take much to throw something off....

[Bergsholmen]

I do know that😉
I am a former agriculture mekanic, but have not been very deep info outboards before.

The ECU is getting "unrectified" power/charge from this red og yellow wires, so I suspect (hope) this is the problem.

Have also had the feeling of low/bad charging the last times I used the boat.
That is definantly because of this failure.

[Solarman]

Clean/ replace rectifier connectors. When good, then using the service manual You need to check output of magneto, and output at rectifier/regulator. If both are working, check plugs and coils. Once you have checked these areas, post back and let us know.

Good luck, post back when able.

[Bergsholmen]

I finaly did find some time too go to the harbor and boat.
To change the burned connectors and check if the is more things wrong.

Started with the connectors from battery charging coil, changed them and check for spark.
Check syl.1 good spark, syl.2 no spark, syl.3 no spark, syl.4 good spark.
At the same time as I tested syl.4 the ECU "woke up" making the "beeping" sound in buzzer. And the High pressure pump started.
"My understanding is that the ECU need the battery charge coil too "power up"

Ree tested syl.2 and 3 and found good spark.
Mountet all sparkplugs and she started right up..
Had no time to go out to sea today, but I am happy that I found the issue and the engine is running again.

Happy guy today😉