2000 Islandia Fuel Problem? Troubleshooting guidance appreciated.

[Scott Martin]

I picked up a 2000 Islandia recently with a 240 Merc EFI (2 stroke). The boat started and ran well at the owners, but after bringing it home, I would start the boat and it would immediately stall out. Being that there was little fuel left in the tank (it was practically empty), I filled the tank with fresh fuel and added stabilizer with no change.

Symptom: Boat starts after sitting for a long period of time, but immediately stalls out and will not start again (almost like it's starving of fuel).

To date, here's what I've done:

1. Replaced Fuel / Water seperator filter (has some water in it) - No change
2. Replaced the plugs sine I was in there already (Old plugs were slightly black as expected) - No Change
3. Removed the fuel hose from the lift pump and checked to see that fuel was being pumped up it was.
4. Replaced the Port Side Temp Unit (old unit jacket was worn through) - No Change.

My thoughts on next steps:

1. Remove and inspect the mechanical fuel pump (perhaps disassemble and clean - not sure where to find a gasket / diaphragm kit).
2. Inspect Vacuum line that supplies the Pulse pump / or replace
3. Remove VST drain plug and test if there's fuel being delivered - perhaps inspect VST Float and needle valve.

My question to the experts is, am I going down the right path? Is there anything else I should check as part of this process that would typically cause this issue? Your guidance is appreciated.

Best,

Scott

 

[Scott Martin]

Moving to the main thread as this "Premium" forum doesn't seem to get too much action.

 

[Dr Honda]

To be very honest with you... if you want a fast answer on the Merc powered boats... just post in the regular Merc section. I don't visit the premium sections very often. (and I'm the Merc guy) Actually... I'm going to move this, and keep it linked here.

OK... the first thing may sound simple, or even stupid... but did you run the bilge fan first? When the bilge is full of fumes... it will choke the fresh air. (The deck lid up may not be enough)


Since the boat is new to you... I would...

1) check the compression. You are looking for 125 psi on a cold engine, and open throttle.
2) Verify fuel pressure. There is a Schrader valve on the vapor tank. (like a tire valve) You are looing for around 48psi. (but I will have to double check that)
3) Yes... remove the vapor tank plug, and verify fresh fuel is getting up into it.

Do that... and we will move on. (next is ignition)

 

[Scott Martin]

Thanks for the insight Dr Honda!

Lifting the deck lid and running the blower was one of the first things I tried (having read some of your posts in response to similar issues).

Now in regards to running a comp test, since there's a neutral safety switch in place how do you get the motor to turn over at WOT? I'm assuming I'll need to jumper the Neutral Saftey Switch in order to do that?

Hopefully I'll be able to wrench on it once this rain stops. I'll post the results.

Thanks again,

Scott

 

[Dr Honda]

The starter solenoid is on the side of the engine. You can jump it. Or, do it with the throttle shut and expect a slightly lower reading.

 

[Scott Martin]

OK so here's where am at and I am stumped.

1. Tested Compression at WOT (130-132 lbs on all six)
2. Found there was a vacuum line broken on top of the VST & Replaced it - no effect
3. Removed the plug on the VST & turned the key barely noticed any fuel coming out of it.
4. Check the fuel feed coming into the VST and there is plenty of pressure coming into the unit.
5. With the key on I could hear and feel the fuel pump on the VST working but when I checked the shrader valve on top there was no pressure.

Now I'm stumped as to what to check next. Any additional troubleshooting tips would be greatly appreciated.

-Scott

 

[Dr Honda]

Hummmmm.


Well.... it sound like you are getting minimum fuel into the vapor tank for what ever reason.


Just to verify... The hose after the large fuel filter, that would feed the vapor tank, has good flow. (right?)

If the fuel flow from the filter is good and strong... then I would open the vapor tank, and clean it out. There is a float and a valve. If it's sticking, you wont get fresh fuel in. Also, there is a screen at the bottom of the high pressure pump. If it's clogged, then you won't get enough fuel to get the higher pressure flow for the injectors.

 

[Scott Martin]

So I finally found the root cause of the issue. The Needle Valve in the VST tank was completely stuck in place which would not allow any fuel / or very limited fuel into the VST tank. New parts coming tomorrow, hoping to get it running and the in water soon.

 

[Dr Honda]

Yep... that would do it.

I'm sure it will work for you now.

 

[Scott Martin]

I swear this boat is driving me nuts. Anyway I replaced the float and needle valve on the VST and reinstalled it on the boat; however I now seem to have an issue with the relay on the lift pump. If I wire the lift pump directly to 12v it works just fine, but won't engage with the key on when connected to the relay. I checked all the fuses (3amp on the lift pump) and the 3 fuses for the EFI system and all were fine. I also replaced the relay with a new one with no change. Using a test light I get a solid 12v on one pin, an intermittent 12v pulse on the other pin (red/black striped wire) and a solid ground but I the relay won't click or turn on.

I'm not sure where to look next or what else to test. I'm tempted to wire the lift pump on a switch.

 

[Justintime_3]

Not trying to be a d@#k but is the lanyard attached, is it possible that the lanyard has to be connected for the fuel pump to come on. Not sure here but just trying to help. And not trying to insult your intelligence.

 

[Scott Martin]

Not a bad question JustinTime. The lanyard is attached and just to make sure that the lanyard safety switch isn't malfunctioning I bypassed it with a jumper.

Now some additional troubleshooting I've done today:

1. Tested both the lifter pump and the VST pump by plugging a jumper directly to them (both come on and function fine with a negative jumper)
2. Validated the ground circuit on the lifter pump / relay with a continuity test with the relay engaged (0 resistance)
3. Noticed that I'm still getting a pulse from the "feed input" to the relay when the key is turned on, and not a steady 12volts which is making believe there is something wrong with the input feed.

I tried finding the correct wiring diagram for this boat but can't seem to find the exact match.

Lastly I'm thinking I might find a spare fused circuit off the fuse panel that only turns on with the key on, and use that as the feed to my fuel pump relay as a work around. Has anyone ever done anything similar?

-Scott

 

[Scott Martin]

Well it turns out the high pressure pump on the VST was faulty and kept shorting out. Replaced the pump and all is running! Time to put that bad boy in the water.

 

[Dr Honda]

I swear this boat is driving me nuts. Anyway I replaced the float and needle valve on the VST and reinstalled it on the boat; however I now seem to have an issue with the relay on the lift pump. If I wire the lift pump directly to 12v it works just fine, but won't engage with the key on when connected to the relay. I checked all the fuses (3amp on the lift pump) and the 3 fuses for the EFI system and all were fine. I also replaced the relay with a new one with no change. Using a test light I get a solid 12v on one pin, an intermittent 12v pulse on the other pin (red/black striped wire) and a solid ground but I the relay won't click or turn on.

I'm not sure where to look next or what else to test. I'm tempted to wire the lift pump on a switch.

It only pumps when you are cranking the engine. It's basically the "Lift Pump" to fill the system. Once the engine is running... the vacuum pump takes over. (the square next to the lift pump)