2003 ox66 200 intermittent shut down

[abrngolf]

I recently purchased a 2000 Proline with a 2003 ox66 200. The issue I'm having is that the motor
cranks and runs fine until it just quits. It will fire again after sitting for maybe 10-15 minutes. This can be at idle or WOT. I put a fuel pressure gauge and get about 32 psi until it quits. Then it goes to zero. Fuel line was replaced and a new water separator was installed about 6 months ago. The anti-siphon valve was also replaced. Bulb will pump up when it stalls, pressure still reads zero. I dumped the clear filter on the side of the motor and it did have some water and debris in it. Ran it some more and appears to be clean. Should I start at the VST and work my way back with filters? I have read a lot of threads and think it might also be the fuel pump relay. Any help would be appreciated. This is my first boat. I'm not a mechanic but I have been trying to educate myself on the motor and fuel system.

 

[QBhoy]

I’d be suspecting a battery issue, from what you’ve said. Or at least a charging issue. Typical symptoms of the engine being able to start and run, until the battery (without being sustainably charged by a stator or alternator) is no longer to sustain the demand of running the various requirements of an engine like this. Maybe have a look at that first off.

 

[abrngolf]

Batteries charging normally. Alternator showing 14 volts.

 

[dingbat]

Motor is known for having a finicky fuel delivery / filtration system. Special attention must be given to all the filters and pumps in the system.

Having said that, have you checked to make sure you have spark on all cylinders when the shutdown occurs?

There are a number of electrical components in the ignition system that are temp sensitive. They work when cold but fail when heated. Ignition condensers are famous for this type of behavior

 

[99yam40]

I recently purchased a 2000 Proline with a 2003 ox66 200. The issue I'm having is that the motor
cranks and runs fine until it just quits. It will fire again after sitting for maybe 10-15 minutes. This can be at idle or WOT. I put a fuel pressure gauge and get about 32 psi until it quits. Then it goes to zero. Fuel line was replaced and a new water separator was installed about 6 months ago. The anti-siphon valve was also replaced. Bulb will pump up when it stalls, pressure still reads zero. I dumped the clear filter on the side of the motor and it did have some water and debris in it. Ran it some more and appears to be clean. Should I start at the VST and work my way back with filters? I have read a lot of threads and think it might also be the fuel pump relay. Any help would be appreciated. This is my first boat. I'm not a mechanic but I have been trying to educate myself on the motor and fuel system.

might check to see if 32psi is the correct spec on what pressure you are reading. ( Rail or even the lift pump pressure)

If you still have spark on the plugs, then you need to find out if the VST is running out of fuel or if injecter pump is shutting down when it dies.
quick way to tell would be to turn the key off as soon as it dies and then try pumping the primer bulb to see if the vst is low on fuel, or drain the VST to see how much fuel is left in the VST. Compare that to how much you can drain out when the VST is full

also if you had water in the filter, you can bet you have water in the tank too.
might be a good idea to drain it completely and clean it out.
the pick up tube does not go all of the way to the bottom of the tank, so you cannot remove everything from the tank with the pick up tube just sucking it out

 

[abrngolf]

might check to see if 32psi is the correct spec on what pressure you are reading. ( Rail or even the lift pump pressure)

If you still have spark on the plugs, then you need to find out if the VST is running out of fuel or if injecter pump is shutting down when it dies.
quick way to tell would be to turn the key off as soon as it dies and then try pumping the primer bulb to see if the vst is low on fuel, or drain the VST to see how much fuel is left in the VST. Compare that to how much you can drain out when the VST is full

also if you had water in the filter, you can bet you have water in the tank too.
might be a good idea to drain it completely and clean it out.
the pick up tube does not go all of the way to the bottom of the tank, so you cannot remove everything from the tank with the pick up tube just sucking it out

Trying to find someone local to drain the tank. Only guy I have found so far said $400-600 at least. I can build a fuel transfer system for $400.
When it dies, the bulb is not firm, but not sucked flat. I can pump it back up with about 3 squeezes. Even if it gets hard the motor just cranks with zero fuel pressure. I have ordered new filters for the motor and VST.
I'm thinking it's the main fuel relay or the high pressure pump.
Spec on fuel pressure is 35.

 

[99yam40]

if you truly believe the VST is not running out of fuel and the pump in the VST is not running when it dies, then monitor the + to the pump to make sure it stays on.
the ECU should toggle the neg to make the pump run, it will not run if the + is not there

 

[abrngolf]

Will do. I actually noticed that the red wire connection to the VST was loose.
I'll check the + when I run it.

 

[99yam40]

loose red wire would mean a bad connection to me,
depends on what your definition of loose is

 

[abrngolf]

Wiggled the wire and it was very loose. Pushed down on the top of it and it seemed to seat itself. Haven't cranked it since. Will update when I do. Also ordered new filters for VST and side of the motor.

 

[99yam40]

( if these are plug together connectors)
I would unplug it and inspect the connectors to see if corrosion is a problem, clean , and lube them up.
disconnecting and plugging back together may help clean them also

 

[abrngolf]

They are eye connectors with a rubber boot. Checked and they are secure.
Gonna put a new filter in the vst, but it has a stripped screw on the back side.
Those little Phillips are a pain. I'm gonna try to get it loose. Hope I don't have to drill it out. Already changed out the filter on the side of the motor.

 

[99yam40]

need Japan type screw driver bit not regular Philips.
and an impact type driver to break it loose.(Type you hit with a hammer) if they are stuck, just to loosen

 

[abrngolf]

Another question.. Has anyone tried using aftrmarket high pressure fuel pumps? I assume they are crap but it would be nice to know if the OEM parts
are worth the hundreds of dollars difference in price.

 

[abrngolf]

need Japan type screw driver bit not regular Philips.
and an impact type driver to break it loose.(Type you hit with a hammer) if they are stuck, just to loosen

Ordered the screwdriver set. Should be here this evening. Anxious to check out the filter in the VST.

 

[abrngolf]

need Japan type screw driver bit not regular Philips.
and an impact type driver to break it loose.(Type you hit with a hammer) if they are stuck, just to loosen

OK. Finally got the screwdrivers on the second try. Took apart the VST and replaced the filter, even though the old one looked squeaky clean and the VST was spotless.
Reconnected everything, and cranked her up. Still only getting 32-33 lbs
at the fuel rail. Thinking about getting a new high pressure pump.
So far I have drained the water separator which is 8 months old, changed the filter on the motor and inside the VST. Took a sample after running the motor and fuel looks good. Just a tiny amount of water in the separator. Is 32 gonna make me run lean? Don't want to be doing a rebuild.

 

[99yam40]

are you sure you gauge is correct?

does the pressure spike when you 1st turn on the key/start and then drop back?

I believe there should be a pressure regulator that controls how much to recirculate back to control pressure in the rail

 

[abrngolf]

are you sure you gauge is correct?

does the pressure spike when you 1st turn on the key/start and then drop back?

I believe there should be a pressure regulator that controls how much to recirculate back to control pressure in the rail

No spike. Stays at 32-33 psi. It's a new gauge. I had another that broke but it also registered the same while it was working. And again, do you or anybody you know have experience with aftermarket pumps?

 

[99yam40]

no I do not, but if the pump can pump higher pressure and the rail regulator is dumping too much pressure,
I would think a new pump would not help

 

[boscoe99]

Does the fuel pressure vary with the throttle being advanced and retarded? It should.

At key on the fuel pressure will be high. Start the motor and it should drop considerably at idle. As the throttle is opened the fuel pressure should start to increase. Retard the throttle to idle and the fuel pressure should go back to its original value.

Many use aftermarket fuel pumps. Walbro for instance. They can be just as good as the pump from Yamaha. Which at times are made by Walbro.