Excess carbon on plugs...ideas?

[linesider 159]

Long story short had a running issue. Did all filters including injector and high pressure filters ( they were full of crap). New plugs were done, new tps, new battery switch, and new battery cable. Motor ran great except a slight hesitation at 3500-4000 that almost felt like a miss and would idle around 1k rpm when cold. Motor did seem to smoke a little more than usual. Fast forward to yesterday when I go run the boat and it falls on its face and wont go over 4700, then begins to run like crap all all rpms, stall at idle, etc.

I pull the plugs and find most are wet and uniform but number 2 and 4 are pretty carboned up and completely dry. Any ideas? I was thinking an injector stuck open that fouled the plugs.

Motor is a 2005 250 vmax HPDI

[201pro]

Which model is this? I assume HPDI?

[Tonyc]

Send the injectors out to be cleaned and tested.

[linesider 159]

Sorry guys, 250 VMAX HPDI. Im going to pull injectors. Threw 2 new plugs in yesterday and fired off without backfiring or rough idle. Lots of smoke though so I think the injector has failed.

[Tonyc]

If the injectors are running rich that will foul the plug(s). Best to have injectors flow tested, cleaned and calibration done on them to put back in spec. Had mine done four years ago, HPDI 250 was missing at wot, one injector was running lean. Saved me before I lost the outboard. Rich did mine, he knows his stuff.