Long story but may be useful for background. I have a 2003 Stingray 190LX that had a Mercruiser 4.3L V6. ICM died on my last year after lightening hit the boat, fried some electronics. I tried to have the ignition switched over to an HEI distributor but never could get it to run right.
This spring, I purchased the right ICM module for the boat and got rid of the HEI setup. After putting the boat back in the water, ran the SAME WAY as it did with the HEI installed. I traced and diagnosed problems left and right. While tracing problems, I noticed some "chocolate milk" spitting out of the tubes coming from the valve covers. Thought it was a blown head gasket, but after breaking down the engine, it was a cracked block.
So............ bought a brand new longblock crate motor 4.3L, moved my accessories and waterpump over to the new engine, all other items, and STILL, ran like a dog. Decided to take ICM and other "computer" controlled stuff out of the loop. Installed the HEI distributor back in the engine, picked up 12v wire for power and she runs like a scalded dog.... Had to rebuild the carb first, had old gas and was needing rebuilt anyway.
Took the boat to the lake last Friday, ran it for 4+ hours without a single engine problem. Everything ran perfect, no misses, fired right up, etc.,.,....
The only problem left is the shifter. From what I can tell by reading, there's a shift cutout switch that momentarily kills the engine to make it going into Fwd/Rev easier. It's NOT connected as both connectors to the ICM are unplugged now. Prior to changing out the engines, there wasn't a shift problem, so I'm at the point of "guessing" this is the problem. I did check the cables for wear, none that I can see or anything that's obvious.
I see the two wires coming from the shift cutout switch, but don't know if it's a 12V switch. My thought is the put the power to the HEI distributor through the switch. Is that the right thing to do?
This spring, I purchased the right ICM module for the boat and got rid of the HEI setup. After putting the boat back in the water, ran the SAME WAY as it did with the HEI installed. I traced and diagnosed problems left and right. While tracing problems, I noticed some "chocolate milk" spitting out of the tubes coming from the valve covers. Thought it was a blown head gasket, but after breaking down the engine, it was a cracked block.
So............ bought a brand new longblock crate motor 4.3L, moved my accessories and waterpump over to the new engine, all other items, and STILL, ran like a dog. Decided to take ICM and other "computer" controlled stuff out of the loop. Installed the HEI distributor back in the engine, picked up 12v wire for power and she runs like a scalded dog.... Had to rebuild the carb first, had old gas and was needing rebuilt anyway.
Took the boat to the lake last Friday, ran it for 4+ hours without a single engine problem. Everything ran perfect, no misses, fired right up, etc.,.,....
The only problem left is the shifter. From what I can tell by reading, there's a shift cutout switch that momentarily kills the engine to make it going into Fwd/Rev easier. It's NOT connected as both connectors to the ICM are unplugged now. Prior to changing out the engines, there wasn't a shift problem, so I'm at the point of "guessing" this is the problem. I did check the cables for wear, none that I can see or anything that's obvious.
I see the two wires coming from the shift cutout switch, but don't know if it's a 12V switch. My thought is the put the power to the HEI distributor through the switch. Is that the right thing to do?
