TBI is a very simple system it's mid 80's tech and can be checked for easily for system error's, the below vid's are not professional by any mean's but it will shed some light at a very low cost.No boat engine's but they are pretty accurate

http://www.secondchancegarage.com/public/186.cfm

https://youtu.be/B8EVhFc5Yqw mefi uses a 5volt signal

https://youtu.be/xutynSVO0xI

https://youtu.be/mL0B-I6WP6s

https://youtu.be/lnsLJeboslk?t=91

https://youtu.be/bPAIFL8VH9w

https://youtu.be/FJobCD6y8fk

Cheap replacement parts

https://www.rockauto.com/catalog/raframecatalog.php?ck[ID]=0&ck[idlist]=0&ck[viewcurrency]=USD&ck[PHP_SESSION_ID]=omrr2rookq4l9i5hs7bh1l1re6

Good file and it does have your engine

https://drive.google.com/file/d/0B3w...Z2s/edit?pli=1

Silly Question but does that boat have a molded in swim platform, Tubular or none at all?

Chris

Just some words - and no offense to anyone and I am saying this in a positive way as that is great for anyone who works on their own boat and can properly fix it without spending weeks or months and a whole lot of parts changing being wasted money & time down the rain.

Words of wisdom if you are going to be working on your app. Start with the basics - scan motor, fuel pressure testing, compression testing, clean your flame arrestor, check for fuel restrictions and fuel leaks. Separate whether you have a fuel delivery side problem or and engine side / fuel delivery side problem. Take the boats fuel tank out of the mix and run it on a portable 6 gallon fuel tank and new fuel line to your engine side - fuel inlet. go lake test the boat - do not run no on the water hose only - needs to be on the water fully under engine load. ( Boats running on a water hose are unloaded and can be hard to duplicate engine running problems).

If problem still exits - its your engine side that has the problem... Fuel pressure testing, what are the psi @ idle, acceleration, mid range and fuel throttle. Does the fuel gauge psi readings drop off when you accelerate ?

Next - Scan the engine and look into the history for faults. IMO you have a fuel pressure problem possible from the fuel pump(s) and make sure the screen under the fuel pressure regulator is clean and clear - also there is an o-ring to seal the regulator to the fuel cooler that needs to be in perfect shape and sealing well. This is very important as well FYI.

Good luck with it. I said enough and hopefully spot on to your problem(s). Report back testing results and or any fixes or still the problem.

Very much in agreement fuel pressure would be the very first check, Oreily's has a the fuel pressure test kit i would assume anyone that would attempt to check the system's would have a working knowledge of the component's and the electrical connection's and how easily corrosion can make even diag testing system fruitless.

I'll have to order the special fitting to test the fuel pressure

I finally got a fuel pressure reading 32-33 at idle and 30 when under load checked the timing was at 8 degrees with the computer set in base timing mode I'm still having an issue with it falling on its face