'05 21v Problem Maybe fuel?

[cocheese]

Last weekend we were left stranded on the lake. After pulling one skier and then floating for about an hour, the boat ran really rough when we cranked it up like it was starving for fuel. When we gave it throttle, it died but would recover when we returned to neutral. After shutting it down and cranking it back a couple more times, the boat then would crank but only for a second and shut off. We received a tow back to the marina. When we got back to the marina we cranked it up to show my father-in-law what it was doing and it fired up and ran like nothing was wrong. I got it back home and pulled the fuel filter. It was hard to blow through so we replaced it thinking problem solved. Wrong! Today, filled with confidence, we took the boat out for the second time since we had this problem. We rode around all day with no problems. Stopped to get ice cream for about an hour and when we cranked the boat, same problem. Luckily, this time we were at a marina and did not need a tow. The ironic part to this story is that there was another Supra having the exact same problem as us. His is a '07 21v and ours is an '05. What could cause two similar boats to have the exact same problem? I asked him where he last filled up thinking it might be bad gas, but he filled up on the other side of town. What could it be? Any suggestions?

[lowdrag]

Your problem sounds exactly like what happened repeatedly to my '06. It ended up being vapor lock and it was almost a given that every time I stopped the boat for while with a hot motor it would happen. After numerous trips to the dealership and them not being able to replicate the problem I started looking into it on my own. I bought a fuel pressure gauge and hooked it up in a semi-permanent fashion using zip ties to keep the hose away from anything that could rub it or melt it. There is a valve on the fuel rail that looks like what you would find on a tire. You can usually find a pressure gauge that will fit at any autoparts store. I mounted it and ran it in the driveway to make sure there were no leaks or other problems before going out on the water. Normal fuel pressure should be around 60 psi. When mine had problems it was usually between 10 and 20 psi.

The other good thing about fuel pressure gauge is that it has a pressure bleed off valve with a long length of tubing attached to it. When the boat wouldn't start, I'd run the tubing into a container and bleed the pressure off the fuel system. I'd usually get a lot of air and some very hot a foamy fuel but once the pressure was let off the system, the pump would prime and the boat would run fine until I stopped and let it sit again. The long term fix could be as simple as replacing your fuel pump. If it isn't in top working order it may just have trouble priming itself under certain conditions. The other fix would be to take it to the dealership. They should already know about this as there was a factory fix for boats with this problem. If they can confirm that it is vapor lock, they will most likely mount a seconday, low pressure fuel pump near the fuel tank. That pump forces the cooler fuel from the tank into the primary pump which will then be primed and work fine. You may also be able to get this covered under warranty since they know it was a problem on a lot of these boats.

[cocheese]

just got off the phone with the dealership that we purchased the boat from and they told me it is a common problem with the indmar motors in a supra and the solution was to cool the motor better when stopped. He said that when the motor is turned off, there is no water running through the motor to cool it so it gets hotter and hotter. Their solution was for us to run the blower and open the hatch when stopped to help keep the motor cool and if it does vapor lock, poor water over the fuel pump to cool it down. This concerns me. If this is an ongoing problem with supra and indmar, there has to be a better solution than this. If I would have known of this problem before hand, I would have considered another boat. There has got to be a better solution other than don't shut the boat off after a extended period of boating. Any ideas?

[cocheese]

OK, just got off the phone with a local dealership and he said that it is not a common problem but is becoming one. He blames it on a combination of things. First being the quality of gas and second being the lake we ride on is heated. He said the quality of gas offered today is not near what it used to be and that combined with warmer water circulating through the engine makes for a sensitive combination. His solution was similar to the other dealer in that we need to change our boating habbits. Whenever we stop for extended periods of time, we need to run the blower and open a hatch to help keep the engine cool. It all makes since to me and we will see if it happens again.

[H2Oman]

cocheese, is this a new problem on you 05 boat?

[Jon]

Supra and indmar have a fix for this. Tell your dealer you would like to go with the two pump option that indmar has come up with to fix this. Hopefully they will know what you are talking about.

[cocheese]

this is a new problem for us considering we bought the boat used over the winter. We have been fixing minor bugs ever since.

I will call our dealer(s) tomorrow and see what they have to say about the dual pump option. I don't think either of them have experience with it. They both acted like there was no solution. Is this something that I could do myself? Where is the second pump installed? Is there an upgrade kit from Indmar? Would this be covered by Supra's warranty? Thanks for all your help.

[Engine Nut]

Last weekend we were left stranded on the lake. After pulling one skier and then floating for about an hour, the boat ran really rough when we cranked it up like it was starving for fuel. When we gave it throttle, it died but would recover when we returned to neutral. After shutting it down and cranking it back a couple more times, the boat then would crank but only for a second and shut off. We received a tow back to the marina. When we got back to the marina we cranked it up to show my father-in-law what it was doing and it fired up and ran like nothing was wrong. I got it back home and pulled the fuel filter. It was hard to blow through so we replaced it thinking problem solved. Wrong! Today, filled with confidence, we took the boat out for the second time since we had this problem. We rode around all day with no problems. Stopped to get ice cream for about an hour and when we cranked the boat, same problem. Luckily, this time we were at a marina and did not need a tow. The ironic part to this story is that there was another Supra having the exact same problem as us. His is a '07 21v and ours is an '05. What could cause two similar boats to have the exact same problem? I asked him where he last filled up thinking it might be bad gas, but he filled up on the other side of town. What could it be? Any suggestions?

Some of the information posted regarding the two pump system that is now standard on our engines is correct but that system does not necessarily apply to your engine. The two pump system was primarily designed for the 340 HP catalyst equipped engines that create extra heat in the bilge because of the catalyst. This condition did not occur till the 2007 model year. We had no vaporlock issues in the 2005 and 2006 model year before the catalyst engines. I suspect that if you are indeed experiencing a vapor lock situation that it is being caused by some other issue. The most likely is winter blend fuel. Every year in the spring there is left over fuel that is blended to vaporize at lower temperatures for ease of starting in the winter. The problem is that when it gets warmer, this fuel vaporizes too easily and leads to vapor locking. This condition generally passes after a short period of time ... after the winter blend fuel is used up. Did you buy your boat from a private individual or from a dealer? If you bought from a private individual, contact them if you can and ask them if they experienced this problem. If they say no, just wait it out and buy fuel from someplace that you know sells lots of gas. If they did have a problem, then there are some other things to check like the fuel tank vent, the anti siphon valve and even the fuel line routing.

Although you could choose to add a second fuel pump to your engine, it would not be covered under Indmar's warranty. I suspect that you do not need the second pump and that by just being patient your problem will go away.

Larry Engelbert
Indmar Service

[lowdrag]

While I realize that Larry is the in house Indmar expert, I respectfully have to disagree with some of the things in his post. Specifically the statement that there are no vapor lock issues on the '05 and '06 boats. It's simply not true. I spent a lot of time and effort diagnosing the problem on my boat (an '06) and it was most definitely vapor lock. It did not matter what time of the year it was or what blend of fuel was in it. I was pretty much guaranteed that it would not start after sitting for any amount of time with a hot motor. I'll gladly reconsider my statement if anyone can tell me the air and foamy fuel coming directly from the fuel rail could have been caused by anything other than vapor lock. While trying to get a fix for the problem I ran into several other who had similar experiences. Since the last time the boat was worked on I haven't been able to run it enough to know whether the problem has been taken care of or not. I will say that the fuel could play some role in it because in my area the only thing available is fuel with a 10% ethanol blend. Even then, it is still a vapor lock issue. 10% ethanol blend is very common, especially in the midwest. Since that is the case, it is something that should have been taken into account with the design of the motor and fuel delivery system if it is a possible contributing factor to vapor lock.

[siuski]

Engine Nut, your comments have rubbed me the wrong way. Along with Lowdrag, I have spoken with several that have had this problem, including myself. Lowdrag and I have been experiencing this issue for the last two seasons, and while my issues aren't as severe as his (two or three times a season), that makes at least two for same dealer. Your statement that "We had no vaporlock issues in the 2005 and 2006 model year before the catalyst engines." is completely false. I see no reason that Indmar is flatly denying this issue with the evidence our dealer has collected. From what Low and my dealer have said, they have spent a lot of time trying to dianose the problem and come up with a solution. Yet you offer "it's a fuel problem", OK, how do we get this engine to work with what is available to us? Seems there is a second pump solution, but last I heard they wouldn't install it due to some USCG regs or something to that effect.


I'd like you to tell my wife to be "patient" when she was caught in a isolated thunderstorm and the boat wouldn't run right. That was a fun one to explain over the phone, "honey just calm down, pop the hatch just wait for another 10 -20 minutes or so and the boat should be fine." Wasn't even going to try to explain how to bleed the rail over the phone...