Have they checked the fuel line and bulb for cracks? I know it sounds to simple but while they have it running in the test tank flex the fuel lines and the bulb and if it starts running rough it is sucking air into the fuel line. Just another thought!!!

Been there checked all that man.

I'm no expert either and it sounds like Gary is on to it. My only contribution would be to ask if they've tried using a component cooler at the lake to try to isolate the guilty part.

Are you talk about the fuel cooler? We have removed the cooler all together. Mercury recommended getting rid of it.

Component cooler is a refrigerant thats in a can. It cools a component for a short time, used in electronics trouble shooting.

You could take the boat out and when it starts acting up spray it on a suspect part and you should be able to eliminate parts until you find one thats failing when it gets hot.

Its not a cure all since the problem may not be a component failing when it gets hot but its a possible way to eliminate suspect electronics.

A.K.A Freeze Spray. It might take a lot on an outboard component to get it to have an effect since its not usually a bare board or component most are all sealed up with that rubbery/silicone stuff.

That is an awesome idea! I never even thought about that. I will have to get a bunch and go to the lake one day. It is going to take a lot of that and a lot of time since I have to make a good run with it till it messes up.

Just make sure you use it ONLY on the electronics and no part of the block. Rapid cooling could crack the block. Also it should not need a real large dose on sensors and such. That stuff is 50 plus degrees below zero, so you don't usually need to soak parts. You are just trying to cool it down.

Well I was reading up on that stuff and all it is is 134 refrigerant... But I might try it later this week. We are thinking that it might be the ECM after some further research.

Had a break in one of the fuel injector wires one time. Took forever to figure out and about drove me CRAZY!!!!! It was an intermitant problem like you are having. Just a thought.... You are in good hands with Gary.

Well the ECM is on its way to Simon motor sports to get checked out. Thanks for all the information. I will report back what they find.

Any update.

Have you tried this. Just a thought , i seen two other motors fixed with this being done. Replace leaking REGULATOR DIAPHRAMS

It was the low pressure fuel pump.