[Knightviper]

Ok. Here is goes! 5 months ago I started having a miss begin, it first showed up while idling along @ 6 m.p.h., but it would go away in 30 seconds or so. Slowly it started getting worse. Now it goes on for 30 - 40 mins missing then like a switch is thrown...clears up like nothin happened (until I come off plane again!) It never does it when first started, only after at least 10-15 mins. of run time. When it does it, it feels like a dead miss and I can not get over 1400 rpms (will not plane-out). I have so far: (1) replaced stator (2) replaced trigger (3) replaced switchboxes(both) (4) replaced rectifiers (5) Had merc dealer diagnose it---(reset TPS, sync n lync,set timing---still doing it & they said everything is fine (6) compression is good....cylinder leak down is good......(7) all fuel filters replaced and primary fuel pump rebuilt (8) all grounds good, connections good

Miss horrible now....I have been sayin all along the ecu is bad and not triggering the injectors...Any other ideas???????? I am about to drive 3 1/2 hours to Richmond to have Sanderson look at this thing, as I can't trust anybody around my area in Maryland! Any help is appreciated!!

Viper

[jerryjerry05]

You say the filters were replaced,did you check for water? An inline water/fuel seperator is a great thing to have.Have you replaced the plugs? If you have done that then go for the ride.J

[Knightviper]

yes new filters. And no water in filters. The spin-on fuel filter had a small amount of "black bits" in it... Yes new spark plugs and wires. One thing I found tonight (5-16-09) is some corrosion(light green) leading from the (+) studs of the ign. coil sides that trail to the metal plate they are bolted to. Possible arcing...maybe? it's very intermittant..I am gonna clean it all up and put it back together in morning and try that anyways.

[jerryjerry05]

If the filters are clean and no water.Does it do it long enough to check on a hose for weak spark?
Possibly a bad coil. Check all connections for corrosion and ground.Loose wires. Good luck,J

[Knightviper]

okay I pulled off all 6 coils and cleaned them up. when I pulled off the rubber covers, on 4 of them, the magnets were loose and I pulled them off and cleaned them. There seemed to be cracks in the casings of a few where the two magnets meet down inside the bore of the ignition coils. Has anyone seen this, and should I just replace them all?? I put them all back together and took the boat out and it ran much smoother in my opinion and it only had a "miss" episode one time, and it cleared up in like 6 seconds, then didn't do it again!! Replace all 6 coils???? I checked the resistance on the primary and secondary sides before I went out and all was with-in spec when cold....Is it possible the coils get high resistance when heated up??