2003 SeaDoo Utopia with Mercury 240 EFI Fuel Problems

[M3Man03]

I have a 2003 SeaDoo Utopia with the Mercury 240 EFI (M2 I think) and have been having some problems. After taking it out of storage this year, it fires right up, but when I took it out on the lake, anything past half throttle and the boat seemed to stall out and surge. It would get power then die, then get power, then die... the more throttle I gave it, the more it just fell on its face.

After a lot of troubleshooting and testing things, replacing all the filters, plugs, etc... I tried a separate tank of fresh gas, same problem. However, when I first started it up on the fresh tank, I could give it full throttle right away, which worked, but slowly started losing power.

So I did some testing and thinking... when I turn the key to the on position in the boat, I can see that some fuel pump fills a fuel reservoir and gives full fuel to the engine until that's empty - which I'm guessing is called the vapor separator tank? After a while, the boat seems to catch up and use the extra fuel I get in the beginning and starts to lose power and I have to reduce throttle to keep it from dying.

What part do you think isn't working? Seems like the fuel lift pump isn't working or maybe the float in the reservoir tank isn't telling it that it needs more fuel or is it the high pressure pump? Or something I haven't considered?

Any input would be greatly appreciated!

 

[Tim75]

I have a 2003 SeaDoo Utopia with the Mercury 240 EFI (M2 I think) and have been having some problems. After taking it out of storage this year, it fires right up, but when I took it out on the lake, anything past half throttle and the boat seemed to stall out and surge. It would get power then die, then get power, then die... the more throttle I gave it, the more it just fell on its face.

After a lot of troubleshooting and testing things, replacing all the filters, plugs, etc... I tried a separate tank of fresh gas, same problem. However, when I first started it up on the fresh tank, I could give it full throttle right away, which worked, but slowly started losing power.

So I did some testing and thinking... when I turn the key to the on position in the boat, I can see that some fuel pump fills a fuel reservoir and gives full fuel to the engine until that's empty - which I'm guessing is called the vapor separator tank? After a while, the boat seems to catch up and use the extra fuel I get in the beginning and starts to lose power and I have to reduce throttle to keep it from dying.

What part do you think isn't working? Seems like the fuel lift pump isn't working or maybe the float in the reservoir tank isn't telling it that it needs more fuel or is it the high pressure pump? Or something I haven't considered?

Any input would be greatly appreciated!

Use a fuel pressure gauge to monitor while running. Should be 36psi while key is on, at any engine speed.

It sounds like a weak fuel pump or a stuck inlet needle (vst).

 

[M3Man03]

Why would it be a stuck inlet needle when as soon as I start the boat (when I put the key to on, some pump runs and fills up some sort of reservoir) and it works great for about 30 seconds. Then it seems like the fuel pump just can't keep up or something.

I did order a fuel pressure gauge and am going to replace the fuel pump. There are 2 pumps in this engine, one that's inside the vapor tank thing and one electric one outside. I'm guessing its the internal one?

 

[ripcuda]

The 240efi has 3 fuel pumps. The clickty-clack lift pump (electrical), the main pulse-operated fuel pump (mechanical bolted to the block) and the high-pressure pump in the VST (electrical).

Your fuel starving diag does sound plausible... definitely worth investigating. The lift pump primes the fuel lines (think of it like an electric primer bulb on an outboard), the pulse pump moves the fuel into the VST when the engine is running, the VST pump pressurizes it for the injectors. Disconnect lift pump outlet hose and put in a container. Turn key to ON. Lift pump should be pumping fuel into your container (10-15 secs of priming, then shuts itself off). If that works... I'd suspect the pulse pump. There are rebuild kits for those (just rebuilt mine a few weeks ago).

Another test you could do... see how much fuel is in the VST. Do a full prime and start engine at idle then turn it off. Drain VST into good container from drain screw. Then reprime and run engine until the time where you suspect it is starting to starve for fuel. Stop engine and drain VST again into same container. Did the same amount drain out? If so, pumps good. If less, then you've confirmed the VST is not maintaining the proper fuel levels and starving out the high-pressure pump.

Cheers!

 

[Tim75]

Why would it be a stuck inlet needle when as soon as I start the boat (when I put the key to on, some pump runs and fills up some sort of reservoir) and it works great for about 30 seconds. Then it seems like the fuel pump just can't keep up or something.

I did order a fuel pressure gauge and am going to replace the fuel pump. There are 2 pumps in this engine, one that's inside the vapor tank thing and one electric one outside. I'm guessing its the internal one?

If your vst inlet needle is stuck (slightly open), it can let in gas very slowly. When you run the engine, vst pump demands more gas than engine driven pump can push into the vst (because of the stuck inlet needle).

The inlet needle is aluminum and the seat is brass. Electrolysis can "lock" the needle in place. Disassembly of vst required.

As Ripcuda explained, there are 3 fuel pumps. The final pump (in the vst) has been known to have problems. Like locking up. Not turning. Monitor your fuel pressure gauge while running. Should keep 36psi. If pressure drops to zero, you are close to your solution. Either the pump itself, or the wiring to the pump.

 

[M3Man03]

If your vst inlet needle is stuck (slightly open), it can let in gas very slowly. When you run the engine, vst pump demands more gas than engine driven pump can push into the vst (because of the stuck inlet needle).

The inlet needle is aluminum and the seat is brass. Electrolysis can "lock" the needle in place. Disassembly of vst required.

As Ripcuda explained, there are 3 fuel pumps. The final pump (in the vst) has been known to have problems. Like locking up. Not turning. Monitor your fuel pressure gauge while running. Should keep 36psi. If pressure drops to zero, you are close to your solution. Either the pump itself, or the wiring to the pump.

But wouldn't that always cause a problem? In my initial post, when I first start the engine and the pull up pump runs, it seems to get enough gas to have full power for the first 10 seconds or so.

Does the pull up pump (or the first one) intended to run always? Mine only seem to run when I first turn the engine to "on" not start, for the first 1-2 seconds.

 

[M3Man03]

Here's the image that I have from my manual on the fuel system flow. Where is the 3rd pump you speak of? I only see the 2.

 

[ripcuda]

Here's the image that I have from my manual on the fuel system flow. Where is the 3rd pump you speak of? I only see the 2.

R - is the Lift pump
D- is the Pulse pump
J - is the High pressure pump

 

[ripcuda]

But wouldn't that always cause a problem? In my initial post, when I first start the engine and the pull up pump runs, it seems to get enough gas to have full power for the first 10 seconds or so.

Does the pull up pump (or the first one) intended to run always? Mine only seem to run when I first turn the engine to "on" not start, for the first 1-2 seconds.

My Lift pump (the electric clickity-clack one) runs for ~15 seconds after turning key-ON, then turns itself off. It is not intended to run always, only to prime the fuel lines (think electric primer bulb). Once the engine is running, the Pulse pump moves the fuel.

 

[Tim75]

But wouldn't that always cause a problem? In my initial post, when I first start the engine and the pull up pump runs, it seems to get enough gas to have full power for the first 10 seconds or so.

Does the pull up pump (or the first one) intended to run always? Mine only seem to run when I first turn the engine to "on" not start, for the first 1-2 seconds.

The lift pump is on a timer from the ECU. It will run until it builds pressure (about 5psi) or until the timer expires (about 15 seconds).

 

[SnoopyDoo]

This is going to seem odd but check the tensioner on the drive belt.
If there is one driving the compressor on your model.
If the belt slips it will effect your boat in a similar way.
Also check the belt.

 

[ajaquino]

Im having same issue on my 250 optimax. Ive replaced lines and filters and lift pump. Engine seems to die and only way I can make it out is pumping primer bulb to get fuel up. I just wanted to know what steps I should take next it would really be appreciated. Marinas by me are 4wks backed up.

 

[M3Man03]

Wanted to follow-up to this post with the solution. I disassembled the entire Vapor Separator tank and cleaned it out. Turns out there was a bunch of gelatinous substance (looked green) clogging almost 80% of the intake screen on the fuel pump in the VST. There was also some of it in the channel from the main part of the VST that leads to where the fuel pump sucks it up. Not sure what it was, but once cleaned and reinstalled, things worked very well.

Something else I noticed, with the lift pump, you can actually plug the connector in both ways, but it will not work when the polarity is reversed. You need to make sure to match up the red/black wires when you plug it in. The plug from the lift pump looks the same in both sides, so be cautious!

Thanks for all the help and suggestions!

 

[Speedst-err?]

M3Man03 - thanks for posting your update. This may prove to be very helpful. I've just posted what sounds like a similar issue. Grateful if you would give it a read and give me your thoughts if this also sounds like what was going on with your boat. Many thanks!

2002 Speedster with 240 Merc M2 - erratic RPM