Weak spark

[brandon.moore]

Volvo Penta 7.4gipefs. Hey guys this one is driving me crazy. Last 2 times out I got some random rpm surges of 100 or so rpm from 3000 to 3100 or 3400 to 3500 just for a second or two. Also noticed black carbon line across the transum when I pulled out of the water due to rich or unburned fuel. Well last time out I started and backed off the trailer and 3 seconds later boat abruptly died and wont restart. 12v to coil. I have constant high voltage spark out of the coil to dist but no spark to the plugs. I have replaced the following as I have new or verified working spares. Cap, rotor, coil, icm and distributor. Wires and plugs 1 year old. All connectors inspeced and in good condition. Nothing improved my condition. ECM is last resort. Should I go there?
Fuel pressure is 42lb and spark plugs are wet so I am 99 9% confident it is an electrical issue. Rotor is spinning. Also no codes in the ECM.

 

[dypcdiver]

I had a similar fault that turned out to be the pickup coil (Item 3854001) It finally stopped working completely. It is an easy Ohms test to check.

 

[brandon.moore]

Well it came to me in the middle of the night. Never checked the low side fuel pump. Did it this morning-12v and 0psi. I have a spare to install and will inspect fuel line to the pickup in the tank for restrictions.

 

[itsathepete]

Well it came to me in the middle of the night. Never checked the low side fuel pump. Did it this morning-12v and 0psi. I have a spare to install and will inspect fuel line to the pickup in the tank for restrictions.

You said previously that it had 42 psi fuel pressure. Was this not at the fuel rail?