Looking for some help solving an ignition problem on hp500efi with msd boxes

Was running fine and shut off. I tried all the simple stuff, neutral safety, lanyards, fuses etc etc. has compression, fuel pressure, distributor/rotor is turning , 12v checks properly to box as well as key on 12v and grounds good

I also swapped coil, ECM, module inside distributor, relays etc from running motor and no changes all parts worked on the running motor

It is 2003, not too familiar with the center portion of the distributor on this any chance something wrong there ?

Any advice would be welcome

I am also looking to down load the manual for this engine if anyone knows best place to do that

Finally I have a scanner and no codes

Thanks tom

Hats off to all VETERANS!!

Oops. Also has oil solid oil pressure - and I checked msd box as well on other engine. Thx

touch white wire on box to ground,,do you hear a sparking sound,may have to use a separate spark plug.my guess,msd junk just died on you.

It has no spark at all?
If not, did you go through the test procedure on MSD's website?
Eddie

So you swapped boxes ? Above not clear to me.

Thanks for the info. Did not get to the boat today but plan to check the msd site and test to coil in the distributor next plus I ordered the manual. Thanks. Tom

Since you said you are ordering the manual - just some heads up - I have a Mercruiser OEM service manual for the HP500 EFI to sell if anyone wants it . 65 bucks to your door and it almost still brand new.. Brand new is almost 100 bucks without shipping. - just saying

just an update - it was the coil in the distributor - it did ohm out as open - and you do need to pull the distributor to change it but we are all good now.

another tip is grounding the white wire to the msd box initially did not trigger the spark but then I read you have to repeatedly tap to ground before the box will recognize it and then it sparked

thanks for the help!