2005 Moomba XLV - HELP, Vapor-lock I think?

Does anyone have any suggestions concerning the following, it’s driving me crazy! I live in Salk Lake City Utah and run my above boat in cold mountain lakes where it runs great.

When I take it down to Lake Powell does my problems begin. Once it’s ran pretty hard and then turned off it will not run (will start) but won’t run. I can hear the fuel pump squealing like a sick parakeet and all it will do is sputter around at idle. If I give it some gas it dies. Seems like it’s not getting enough gas.

I let it sit for like an hour it will then run. One time I put a wet cool towel over the motor, fuel pump and electronic ignition stuff and it started up after 5 minutes.

I have changed out is the fuel filter.

I don’t think it has a fuel/water separator at least I can’t locate it. ---- I would of tried that too and would like to put one on it? Can I?

Any suggestions would greatly be appreciated!

Thanks,
Marty

Same thing happened to me changed the fuel filter, and no more problems. Props to Lakota Water sports. I called them looking to buy a new fuel pump, and the service manager told me he just received a memo from Skiers Choice that they recommend changing the fuel filter every 50 hours instead of the 100 hours according to the Manuel. He told me they just replaced one on an 07 with 20 hours. Make sure your using premium gas. Also try flushing the fuel line before you put on the new filter take an empty jug put the fuel line in the jug turn the key so that the fuel pump kicks on. This will get any junk out of the line.

Paul,

Would it only happen when hot?

I was thinking of putting one of those glass fuel filters on it so I could see if it's getting gas from the tank. So thanks for the tip.

Yes only after is was hot. I would have to wait 30 to 45 minutes until it cooled down, and then it would start right up and run perfect until it heated up, and same thing all over again.

Paul,
Same thing happened to me at powell last week.

I heard that Fuel Injected motors were not supposed to get vapor lock so I knid of ruled it out ( but not totally).

This only happened when the engine was hot.

I do not think it was a fuel filter either... If it was why would it only happen when the engine was hot???

Boat ran fine but I was afraid to turn it off because I was worried it would not start again.

I am calling Indmar today so hopefully they can explain it.


My boat is a 2005 21V.

I'm not sure why it only happened when it was hot. I'm not mechanically inclined that's why I called the dealer. They said it's not too uncommon for the fuel filters to clog. The dealer also said take your fuel filter off if you can't blow through it with ease replace it. Heck it was only a ten dollar part, and it couldn't hurt anything. My dealer gave me the part number for the napa filter, and it saved me a two hour drive to the dealer. Problem fixed!

Can you hook me up with that napa part number? I have a napa store down the street.
Thanks
Erik

The Napa part number is 3299 . Good luck hopefully this takes care of it. Finally I get to help someone else out instead of being a sponge.

Paul,

Thanks a bunch. I hope it helps as well!!!
Have a great summer

My friend's 06 21V went through this all of last summer. Every time we would break after our sets and the engine was hot, it wouldn't start. The dealership checked it out and replaced parts but it didn't help. He finally put a pressure gauge and a bleed line under the hatch where we could see it and sure enough, no fuel pressure. I would hold a bottle and bleed the line. It was almost all vapor and hot enough to burn your hand. As soon as I bled off enough mist and vapor to get a good flow of fuel, he'd turn on the key to spool up the fuel pump, the pressure would jump, and boom, away we went. In about 5 or 10 minutes instead of an hour. It was definatly vapor lock. It went back to the factory over winter but he just had a new baby so he's not even sure if it's fixed yet. I thought the fuel injected engines could not vapor lock either, but it sure did and we even video taped it for the dealership. It sounds like exactly the same thing you have going on. If you want to be sure, put in a pressure gauge and a bleed off line and see.

Im just going to take it to the dealership, call Skiers Choice and Indmar and get it fixed right!!!!

Brian
Thanks
for the confirmation. It is not what I wanted to hear but it needs to be heard.

It could be the MAP (Manifold Absolute Pressure) sensor.

The symptoms sound similar to what I was experiencing.

According to the GM spec. the inlet port on the MAP sensor should be vertical facing straight down on no more then a 30° angle. Mine was installed horizontally 90° out. I believe this was the cause of the premature failure and subsequently the throttle response has never been better.

Good Luck!

Brian,

I know a mechanic that might have a pressure gauge and was thinking of doing this. It just sucks doing all this crap while your 8 hours from home on vacation.

Do you mean when you say a "bleed off line" a line so you can let the vapors etc out? If so where do I install it?

E Double U,

I was down at Powell last week too. Did you get your boat from Marine Products?

Have you talked to Skiers Choice and Indmar?

marty

Mine has gotten so bad that it will start to sputter while cruising on the lake if it's over 90 degrees and my RPM's are over 3000.

I called the dealer and they said this is common. (Of course). They told me to replace the fuel filter and install a second fuel pump before the filter.

I'm wonder if it's the fuel pump because it's bolted directly to the engine block and is getting to hot itself but just a guess. I was also thinking about moving the pump and re-routing the fuel line.

Marty

I talked to a Indamr Customer Service rep today. He told me that are a number of reasons that it could be getting Vapor Lock. He first and formost mentioned the type of GAS that is going into the tank. He reccommends 91 octane. He said the mix within the gas ( additives ) will also contribute to the gas vaporizing at a lower temp. He said that the gas must be unobstructed from the tank to the pump. Even the slightest clog in the filter or line or even a kink in the line may cause air in the line and thus vapor lock. He told me on a hot day to ventilate the engine compartment as much as possible and also let the engine Idle for about 3-5 min after a hard set . It will allow the engine to cool faster than just shutting it off.
He said to start with a new Fuel filter ( $11 at Napa )and make sure that all fuel lines are free from clogging and kinking. Next is if you are still having problems it is most likely happening before or at the Fuel pump and not after. This was explained to me: The fuel pump will only pump fuel and not vapor so if the vapor is happening before the pump this will cause it to not pump . If the vapor is happening after the pump then the pump would work because it would have a solid run of fuel to it. (makes sense).

So he said if it continues to happen then after a set to put a cold /cool rag around the fuel pump and it will and should help the gas from vaporizing at the pump.
Skiers choice has ordered Indmar to mount there fuel pump to the engine. Mastercraft and Malibu have changed to have theirs put in the fuel take to push the gas instead of creating a vaccum effect ( as in a Skiers Choice Indmar motor ).

I am going to try to custom fit some sort of Heat Shield ( if possible) between the mount and the pump.

I hope this helps.

Erik

E Double U,

I guess I'm going to install a second fuel pump as was recommended by a dealer in Vegas.

The stuff that the indmar rep told you is the same stuff that marine products told me. I was told that indmar is sending out a second pump for 07 models if they have this problem. Funny thing is out of all the boats I saw down at powell last week with the back compartments open were all Mobius boats.

Does anyone know the psi for the fuel pump that indmar is sending out as a secondary pump for the 07 problem?

Thanks,
Marty

Marty,

I'm the guy who owns the boat that Brian was talking about. I pulled my hair out all last season with this problem. The boat was sent back to the dealership numerous times for a fix and all I ever got back was that they could not reproduce the problem. I have no idea why they couldn't because it was pretty much a given that after the boat had been run for a while it was going to vapor lock. Idling and letting the motor cool down did nothing to alleviate the problem.

The bleed off line that Brian was referring to is actually part of the fuel pressure gauge. I bought one from Autozone for about $30. They have a couple different ones. You just have to get the one that has the right adaptor with it. There's a valve, if I remember correctly, it's right on the fuel rail and looks like a metal version of the valve you would find on a tire. The gauge I got had about a foot or so of tubing between the guage and connection, so I somewhat permanently mounted it using zip ties and making sure the hose could not contact any part of the motor. The bleed valve on the gauge is so you can relieve the pressure from the fuel system before removing the gauge so it doesn't spray fuel when you do take it off. In my case however, it's main use was to bleed the vapor off so the fuel pump could prime itself again.

Just one other caution for anyone else that might think about doing this. If you decide to do what I did, make checking the connection of the gauge to the fuel rail one of those things you do every time you go out. I check it as soon as I start the boat on the trailer and usually everytime I start the boat after we've been sitting for a while. You would want the connection to loosen just enough to let fuel start leaking out. Lock-tite when you install it might not be a bad idea either.

This is the first time I've heard of Indmar sending out secondary fuel pumps. I haven't checked my boat all that thoroughly since it came back from the factory so it's possible that they may have installed one on it. Who knows, my boat may even be the one they used to come up with the solution since it was at SC all winter.

Rob,

I will defiantly do what you had to do if the second fuel pump doesn't do the trick.

Question,
Did you hook up the pressure gauge right after the fuel pump or where did you hook it up?

Thanks for the help Rob,
Marty

I've heard the 07 Supras seem to have vapor lock problems. We have the 340 Indmar engine. Last Friday the engine on our boat vapor locked. The weather was hot and we had been running the engine alot. Before I shut the engine off I noticed it was running rough.

The dealer is now installing an inline fuel pump per instructions from Supra.

When I get the boat back I'll see if I can get a part number.

Richard,

Please do, I have been waiting for marine products to get me the p/n but I haven't heard from them and when I call they say they are trying to find it.

Thanks,
Marty

Looks like we will all need the info. Please pass it on to all of us. can you explain how the extra pump is supposed to solve the vapor lock problem or how it is going work.

Richard,
Is it going to be covered under the warranty??

E Double U,

I'm thinking about either moving the pump off the motor all together or making a heat shield. Thanks for the suggestion. I don't want to drive 8 hours down to Powell again and have the issue rear it's ugly head. I know it could be much worse because all we have to do is wait it out and sooner or later the engine starts.


Marty

Regarding the 07 Supra - It is covered under warranty.

When I get the boat back I'll do what I can to get the part number. I may not see the boat until Wednesday - parts are on order.

rich

Any word yet

Sorry no parts yet. I am checking daily.

rich

i would first try to reroute your gas line or wrap it with an insulation tape. the line is probably near a manifold (hot) causing the gas to boil and thus the vapor lock. just a thought

Alan,

The gas line from the tank to the fuel pump is fine and is away from any engine part up to the point of where it connects at the fuel pump. The problem is the Fuel pump is mounted to the side of engine block. that is where the problem is happening. that is why there is all the talk about creating a heat sheild at the pump. the line from the pump to the fuel injectors can also get hot but the problem is from the pump to the fuel injection manifolds.

Marty,

The pressure gauge is an easy install. If you look and the fuel rails that run along the top of the motor you'll find a fitting that looks just like the valve on a tire. The gauge just screws on to that fitting.

E Double,

The seconday pump solves the problem by pushing fuel to the primary pump. The secondary is a low pressure pump that is mounted away from the engine where it doesn't get hot enough for the fuel to vaporize. If the fuel around the primary vaporizes and the pump can't prime itself the secondary just pushes fuel to it so it primes and will essentially purge the fuel system between the primary pump and the injectors by just pushing the vapor out. I think I've heard that there were several years that Mastercraft had a similar problem and used a solution like this.

It seems like one of the things that worried me about the new ETX Cat motors is coming true. From what I've heard it sounds like they are the ones that are most susceptable to vapor lock in the '07's due to the extra heat generated in the engine compartment by the cats. Hopefully the secondary pump will become standard and take care of the problem.

The inline fuel pump is mounted as Rob describes above. Attached is a picture w/ the part number.

rich

Thanks guys for all your help. Thanks for the part number for the pump rich. Rich where about is this pump mounted in your boat?

If this second pump doesn't do the job I will move the main pump off the engine as well. I thought it would be easier to mount a second pump as my first option verses moving the main pump because it look like one will need to either make or find a longer high pressure fuel line with the right fittings installed to make it possible to move the pump. Just seem easier to slap a second low pressure pump in then move the high pressure one to me. I may be wrong.

-Marty

Rob ,
Thanks for the explanation. Makes sense
Marty,
Thanks for the part number.

Erik

The picture below is taken facing the back of the boat. The second pump is mounted to the left of the transmission. You can see the pump has a mounting bracket.

The dealer told me that no one has had vapor lock problems once the secondary pump has been installed. We will be at Lake Powell end of the month which will be a true test of whether the problem is resolved. By the way, the dealership (Sidewayz, Fort Collins) has been great to work with.

Let me know if you have additional questions.

rich

Rich,
Did they install the fuel filter before or after the secondary pump??

The order starting from the gas tank is

secondary fuel pump
filter
primary fuel pump
engine

I would think you would want the fuel filter before the secondary fuel filter but I am not a engine expert.

rich

Are you guys sure the primary fuel pump is turning on in the first place? The second pump might just be jump starting the primary pump.

Have the fuel pump current ramped to see if the wave form pattern has any abnormalities, and find out exactly what the current draw is.

peter,
You can hear the fuel pump when you turn the key.

The primary pump is definatly switching on, you can hear it spool up. And you can also hear it finally pick up the fuel after we bled off the vapor.

Rich,
I am having the same issues size of pump? Did the dealership do the install? I live in Montana have 06 21V 170 hours lake at 4800 feet 90 degrees.
The reason I ask about the dealership is that I have to travel 115 miles to get there and want to know if I could install the pump.
Thanks

Kenton,
The dealership did do the install and covered the cost of the pump. I think I could have done the install. It doesn't look that hard. Likely, you could do it also.

Have you talked to the dealer to see if they are willing to supply the pump and cover the cost?

rich

Rich,
Changed fuel filter today.I was unable to push much air through the old one, so I am hoping this was the problem
Kenton

I had a similar problem with my MC 190 years ago, after going through a nightmareish trouble shooting process, we found out that our fuel lines were too close to the motor and were causing the fuel in the lines to essentially boil. Once we re-routed the lines further away from the motor, it solved our problem. Not sure if this your issue, but might be worth looking at.

I'm pretty confident Skier's Choice is monitoring this thread..I'd be interested to hear their thoughts on this issue.