Mercury 150 2 Stroke F/I Fuel Delivery Problems

[jasonbailey]

I spent the day getting my a** kicked by a 2001 Saltwater series 150HP Fuel Injected V6 two stroke. It is my brother's rig and I'm trying to help him get the engine to run. It sat for 3 seasons without any use. We pumped 30+ gallons of old fuel out of the tank and replaced with fresh. We also replaced the fuel filter, we have good fresh gas up to the filter assembly.

The motor has good compression and good spark. It will run if I spray premix into the the throats, but immediately dies as soon as that is burnt off. I have a feeling the injectors are full of gunk and need to be cleaned/replaced. 1st off, can they just be cleaned or do they have to be replaced.

Second and most important, I have some mechanical skills, not great, but have some. I've rebuilt carbs on my old o/b, but this is a whole different animal. How difficult is it to pull the fuel delivery system off and clean? Should I even attempt it? Any good places to start so I don't have to take things apart that don't need taking apart? I was thinking of taking the fuel line off of the filter housing that runs to the injection system and try and blow some compressed air through to see if that helps.

Any advice would be greatly appreciated. Thanks in advance.

[CharlieB]

Drain and flush the VST, possible varnish sticking the float and/or high pressure pump inside. May need to disassemble and clean it.

Might still be able to find a service manual here.

http://forums.iboats.com/mercury-mariner-outboards/do-you-need-any-mercury-manuals-pdf-format-309079.html

[jasonbailey]

I downloaded the manual, I'll clean and flush the VST and float today. Looks like a bunch of fun!!! Thanks for the advice, I'll report back as soon as I get it apart, cleaned, and hopefully running again. Thanks!!!

[jasonbailey]

Took the VST apart, it was full of junk. Cleaned the float and needle, cleaned the pump, and tank. Went to put back together and the O-ring had swollen up. I'll order a new o-ring, and hopefully this beast will go.

[jasonbailey]

Ordered the new o-ring from our local Merc Dealer. $46.00, OUCH! It won't be here until next Tuesday. As soon as I get it I'll get it put back together and let you know the results.

[jasonbailey]

I finally got the O-ring and installed. Put everything back together and no joy. it will run if I spray pre-mix into the butterfly. I noticed it has a Schrader valve on top of the VST. How much fuel pressure should it have when cranking? I'll put my fuel pressure gauge on it and see what it says.

It won't even fire on one cylinder without the premix. Could all six injectors be clogged? Any advice on where to go next would be most appreciated.

[jasonbailey]

bump

[CharlieB]

All injectors have a screen on the inlet, if there was any of that liquid 'junk' pumped to them they could be plugged and need cleaning. If the tips are clogged you may have to send them in to Tony Brucado for cleaning.

Are you getting pressure on the fuel rail? @ 32 PSI