TBI flooding issue

[blacksheep2010]

Hi everyone,

Last year I purchased a non-running 1997 American Skier TBX with a Marine Power 350, the TBI fuel pressure regulator spring was rusted and had snapped in half.  I purchased a fuel pressure regulator rebuild kit for a 94/95 GMC truck that has a 30 psi spring.  The boat runs great in the driveway, but when you take it to the lake and put a load on it the boat floods and dies.  The plugs foul with gas and after 30 minutes will restart, but will flood again on excelleration.  I changed the fuel regulator spring to a 13 psi, but now the boat won't start unless the MAP is unplugged.  So my question is, did the Marine Power 350 come with a 30 psi regulator in 1997?  I have changed out the coolant temp sensor, MAP, fuel return line, and thermostat (142).  A tech at the local marine dealer advised the thermostat may be too low causing the ECM to add more fuel to bring the engine temperature up.  I appreciate any help the forum can provide, just need to make sure I have the right parts before I troubleshoot further.

V/r,

Mike

[Midskier]

short answer - no

long answer - call Ron T

Dan T

[RonT]

The say timing is  everything....I got the call about this while riding with Marine Powers CEO on our way to a Boat Builder, had a productive call & answers to try to get this boat running.

[TallTex]

"TBI fuel pressure regulator spring was rusted and had snapped in half"

This tells me water is getting into the fuel and water separator is not being serviced. Must find the source of bad gas.

"I purchased a fuel pressure regulator rebuild kit for a 94/95 GMC truck that has a 30 psi spring."

I do not believe this is correct part or correct # pounds for this application.

"I changed the fuel regulator spring to a 13 psi" "did the Marine Power 350 come with a 30 psi regulator in 1997"

Same as above. Most likely a 25psi. There are also adjustable kits available to tweak to each application that may be unique. Check out/search youtube for this.

"MAP is unplugged"

Probably put engine in the "limp back" mode. MAP hose to manifold needs to be tight with no leaks, use clamps, same with MAP electrical connections, check and recheck they are all good and tight.

"A tech at the local marine dealer advised the thermostat may be too low causing the ECM to add more fuel to bring the engine temperature up"

142 or 150, what does the temp gauge read? Do not believe this is the issue.

Other matters to check/verify:
Timing, absolutely.
Good spark at all 8 plugs
Compression test all cylinders, see where they are, and look for any possible leaks (again search youtube for a "poorboy" smoke tester)