Vapor Lock again

[bdjohnson3]

Had the same problem with our 06 iRide for two seasons. The mechanic couldn't figure it out. We repalced the original fuel pump, insulated fuel lines, insulated the new fuel pump...nothing fixed it. My mechanic finally got Malibu/Indmar to fess up that they were aware this was a problem around 2006, and they actually make a wiring kit for a secondary fuel pump (could have saved me a lot of time and $$ and time spent with bags of ice held against the fuel pump had we known this up front). Mechanic got the wiring kit from Indmar, installed a secondary pump, and I havne't had ONE problem since then - and that was two seasons ago.

[dalt1]

So far I have got away without the secondary fuel pump.

[shawndoggy]

Had the same problem with our 06 iRide for two seasons. The mechanic couldn't figure it out. We repalced the original fuel pump, insulated fuel lines, insulated the new fuel pump...nothing fixed it. My mechanic finally got Malibu/Indmar to fess up that they were aware this was a problem around 2006, and they actually make a wiring kit for a secondary fuel pump (could have saved me a lot of time and $ and time spent with bags of ice held against the fuel pump had we known this up front). Mechanic got the wiring kit from Indmar, installed a secondary pump, and I havne't had ONE problem since then - and that was two seasons ago.

As I understand it the secondary fuel pump was put together to help out supra owners who had a bigger problem with heat in the engine compartment as a result of the introduction of cats. Personally, I DID put the secondary pump in and it didn't help (just like the folks at indmar warned me it wouldn't... that it would really only help out if I had a supra with cats) ... but then again it turned out my problem wasn't vapor lock at all, even though it kinda looked like vapor lock. Since getting my wiring sorted the boat has started very well, even on corn gas on the hottest days.

[Bill_AirJunky]

I had my first experience with vapor lock on this boat on Sunday. We started SkySkiing around 10 am. Rode for like 3 or 4 hrs. Temps got up to about 95. 74 degree water. The last hour or so we just cruised around a bit, then tied up to some friends boats, swam & goofed off. At some point we needed to go in & pick someone up. Started the boat & it started, put it in gear to drive away & got 50' away before it died. Restarted it 5 or 6 times & it would sputter & cough, starting each time, then dieing. Popped the engine cover & checked the fuel pump. The 6" steel loop on top was hot. And the solenoid seemed hot. Put a rag in the cooler & put it on top of the fuel pump. I'll be damned if it didn't start right up & run perfectly from that point on.

Thanks to you guys, I knew what was goin on, how to fix it & I didn't have to get towed in by a pontoon boat.

I'm thinking about rigging some insulation on that loop of steel fuel line over the fuel pump. Not sure that will do anything at all but it's worth a shot.

[MalibuNation]

I had it for the first time this season ... then again it was in the 90s. Even have having my engine hatch open for 30 minutes it would turn but not fire. Had to dunk my shirt in the lake and cool the fuel line and pumps. I'm also looking for a solution.

[FlatBlackCJ]

I have a 02 VLX w the Monsoon engine and I have/had the same issues. I have spoken with Malibu, Indmar, local dealers, a certified MC/Malibu mechanic and all say they never heard of it nor SHOULD it happen w/ FI boats/or cars. I have told them to Google Malibu Vapor Lock and see all the "non-existent" vapor lock. I did all the things the boards have said: New fuel pump, fuel filter, bypass regulator, cycled key on and off several times, purges shrader valve on the fuel rail, insulated the lines and poured cold water on the pump. So far, the cold water works best. Well, I was not content with that so I decided to make up my own fuel system. The biggest challenge was plugging the hole in the end of the fuel rail where the fuel pressure regulator goes. I went to a local pull and pay junk yard and snagged two regulators off a Grand Prix and one off a Cavilier. Went home and cut off the plug portion and welded it to some flat bar and made my own filler plug. Then I added a 40 PSI fuel pump from MSD and a fuel pressure regulator w a return from Aeromotive and some fittings and braided high pressure lines from a local speed shop. Had to do some swapping of fittings to get 1/2 inch out of the fuel tank to the fuel pump, after all is said and done, it works great. We took it out this last week and after some fuel pressure adjustment, she runs likes crazy from idle to wide open. Let it sit for 30 minutes and she fired right up and I threw my spare water bottle in the trash.

This may not be USCG approved, but I have never seen an officer ask to see the engine compartment. Besides, it has all the high pressure stuff a race car would have, so I figure it is as safe or safer than what came in the boat to begin with.

I am attaching my post from another listing. For what is worth, things have worked great so far. I have done all of the things you guys have listed but it never helped. I don't guarentee the results, but I could not take it any more. Especially a couple of weekend ago when we were with a couple of friends that have an X Star and we went to start it after swimming for a little bit and it would not go. That was the last straw fo me. Of course, he had some fun comments to shout out as he rode away.

[Fman]

I had it for the first time this season ... then again it was in the 90s. Even have having my engine hatch open for 30 minutes it would turn but not fire. Had to dunk my shirt in the lake and cool the fuel line and pumps. I'm also looking for a solution.

Have you tried running the blower all the time when outside temps exceed 90 degrees? This would continuously introduce cooler air into the engine compartment and might help eliminate any vapor lock.... might be worth a shot.

[Bill_AirJunky]

Have you tried running the blower all the time when outside temps exceed 90 degrees? This would continuously introduce cooler air into the engine compartment and might help eliminate any vapor lock.... might be worth a shot.

I did exactly this on Sunday & didn't have any other incidents. Typically I do run the blower a lot. But for whatever reason I didn't run it that one time, and the engine sat & soaked in it's own heat for a while.

BTW, DAlt called me last night & we talked about what he's done to get past it. He replaced the fuel filter, the regulator & the rubber fuel lines from the pump to the tank. He double clamped the rubber fuel lines, & cleaned the screens at the pump & regulator. So far, so good. Hope that solves it for ya, Denny. Good to talk to you again.

Not sure I'm going to go to this extent. But I'm thinkin I will replace the fuel filter, check & clean the screens, and add a clamp to the rubber fuel lines.

Edited July 19, 2011 by Bill_AirJunky

[fanthonyv]

Not sure how many people are still experiencing this problem (I still am), but I may have isolated the cause if enough responders on the 'crew' can verify they have the following configuration:

1. V-drive (not direct drive)

2. Optional heater system (with core mounted under helm)

3. Fuel line from tank rests directly on top of heater lines for about 1-foot (also wedged between tank and stringer)

4. Using ethanol based unleaded fuel

5. Heat soaked induced vapor lock symptoms after stopping boat for more than 30-minutes, but not after 3-hours or more of sitting (I.e. Overnight).

6. Typically happens when ambient air temperatures exceed 90 degrees

If everyone experiencing this issue can check off all 6-items, I believe the cause is the "1-foot" of fuel line that is in direct contact with the heater hose. The nearly 170 degree heater line directly tangent and underneath the fuel line is heating that "1-foot column" of fuel which is about 2-feet before the high pressure fuel pump. When conditions present, the fuel pump creates a vacuum (think of using a straw to drink) which further lowers the boiling point of ethanol fuel. The pump gets the residual liquid fuel up to the injectors for about 1-2 seconds (allowing the boat to momentarily start), then begins to sputter...as the 160-180 degree thermally induced and heat soaked fuel, which is now vapor, reaches the high pressure fuel pump. The fuel pump then continually tries to pull the vapor, which continually lowers the vacuum pressure in the line which won't allow the motor to start.

If the 6-conditions above are present in every scenario, I recommend you try the following: isolate the fuel line away (maybe 2-3 inches is enough) from the heater line by the fuel tank. Maybe even wrap a pool noodle or other foam type insulator around it in/on this area.

Let me know if this works. After 4- years and more than a $1,000 of parts (new HP fuel pump, Vapor lock kit, insulation, distributor cap, crank position sensor, thermostat) and countless days of being the scourge on the water, could it really have been this simple? Could Indmar and Malibu have overlooked this basic issue, condition, and simple remedy?

Please try this and let us all know.

Edited August 14, 2017 by fanthonyv

[williemon]

No, not that simple. I have a v drive but for me, the issue did not start until i installed a new Fuel pump purchased from skidim. Always run non E fuel. Then i got the vapor lock symptoms. Even in 70 degree ambient temp, at my home on a hose. Let it run on the hose and pergo flush valve for about 15 min. Then with all hatches still closed, turned  it off and let it sit for 20 min. Then went to fire it back up and had the vapor lock. I traced it to the bottom of the new two stage fuel pump on the engine. Engine would fire up and run for a few sec. the pump would whine, then get hot, then the engine would die. Once i cooled  the pump with water, it would run fine. Adding the second low pressure pump( like in the vapor lock kit) cured the problem.