Lost Spark

[resolute]

Hi, I have a pair of 2001 200hp HPDIs on my 28 foot boat. The port motor is not running properly. It appears that it is not generating a spark in cylinder number 1. the motor will start, and run at 400-500 rpm and usually stall within a minute.
I pulled all the plugs and they all looked similar except #1 which was wet with fuel and clean.
I changed all plugs with new - no change
I changed coil #1 and coil #3 (since #3 shouldn't make a difference at idle) - no change
I confirmed no spark with a spark tester
I checked pulser coil - 310 - 316 ohms on all 6 wires

whats next? should I swap ECU from port to stbd motor? Or is there another more obvious thing I should check?

Thanks for your input.

[boscoe99]

Check the pulser cool to verify that it is not grounded. Or connected to any other coil.

[resolute]

Thanks for the reply. Could you explain how I would do that

[ausnoelm]

Does it have spark on #1 in gear?

[resolute]

No spark in gear although the RPMs go up to 600 because the #3and #2 cylinders kick in.