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ibelonginprison

An effort to battle heat soak induced vapor lock...

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UWSkier

I thought they more or less fixed the vapor lock issue by '04 or so. IIRC, a simple fix (use with caution) is to remove the cap and depress the schrader valve on the fuel rail to relieve the pressure. Obviously only do this with adequate ventilation, no arc risks, etc.

Edited by UWSkier

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ibelonginprison

I thought they more or less fixed the vapor lock issue by '04 or so. IIRC, a simple fix (use with caution) is to remove the cap and depress the schrader valve on the fuel rail to relieve the pressure. Obviously only do this with adequate ventilation, no arc risks, etc.

Haven't had luck with removing the cap, and it's not easy to get to the schrader valve under that massive metal engine cover.

It's possible that my fuel pump is going bad - but it only acts up in that one, specific type scenario where it just bakes for about an hour after running it most of the day - and cooling it off always fixes it.

They probably solved most of the vapor lock issues, but my 06 still gives me the middle finger every now and then when it's hot outside. I also forgot to mention that when it happens water temps are registering at 90-92 degrees, and air temps are usually 95-100 degrees. I don't have this problem when it's not "7th level of hell" hot outside.

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blk93jeepzj

I will attest that the pre-fuel pump solution does work. My 04 did the whole vapor lock issue on me a couple times (dipped a rag in the icy cooler water, then wrap it around the fuel pump to cool it off), added the pre-fuel pump 4 summers ago and have not ever had the issue again (knock on wood). Hot afternoon temps after running hard and stopping for a bit is what would bring on the symptoms, plus mix into the scenario ethanol fuel in the summer heat to make things worse.

We have a neighbor with an 05 and they added the kit to theirs as well after they had the vapor lock experience. They also ran 87 octane with the 10% min ethanol.

Another neighbor with an 05 only runs premium (non-ethanol) and has never had a vapor lock issue.

PS, I did my pre fuel pump kit for the local Malibu dealer for less than the price listed at Bakes (granted that was a few years ago).

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ibelonginprison

The ethanol is really what emphasizes the issue. I don't have these issues when I run non-ethanol fuel (which I run almost exclusively, unless I can't get access to it - then I run stabil additive) I'm going to try to solve the heat soak vapor lock issue while I still have a little bit of ethanol fuel in the tank so that I know I've kicked it in the teeth and won't have to worry about it ever again.

Worse comes to worse, I'll add the pre-fuel pump kit if I have to. But if I can fix it for $30, vs. $300-400....... I mean, that's money towards a new surf board. lol

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GreenMan

IBIP, that's a great write-up. :)

I have the same engine as yours (although mine is installed in the proper direction...!) and experience the same issues in the same circumstances. Prior to our last season I installed the Indmar Anti-Vapour-Lock pump kit albeit with a mod to the flow path but pretty much achieves the same result. Last season I think I only had one episode of likely vapour lock and it was very brief. So, I consider the mod successful.

That said, I assume a big part of the problem is 'downstream' of the HP fuel pump. The pressure regulator is right at the pump discharge so, when you key up, the pump runs but only circulates fuel up to the pump then back to the tank. The entire HP delivery system remains static. Given that the HP delivery line, fuel rails and injectors are high up, directly over the engine (inside the engine cover that has no ventilation to allow any convection breathing and simply stores all the heat soak in a beautifully sealed roof) they must be subjected to the highest temps in the engine bay and surely vaporise. Cranking or idle speed probably flow fuel too slowly through the HP system to quickly cool it and the engine idles rough and will not accelerate properly until the whole delivery system cools below vapour point.

Hadn't thought of opening the schrader valve and can see the advantage of bleeding out vapour and sneaking in a bit of cooler fuel but I don't fancy having liquid fuel or vapours releasing into a hot engine bay while I'm leaning over it...

I would have thought it preferable to have the pressure regulator downstream of the injector rails so that anytime the pump is running, fresh fuel is being flushed through and cooling the whole HP delivery path.

I've never used ethanol fuel and usually use a premium grade.

Looking forward to your next, exciting episode.

Edited by GreenMan

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ibelonginprison

Hopefully my next exciting episode is me drinking a Vodka and Sprite while leisurely floating on my surfboard, celebrating successfully starting the boat after a long heat soak. lol
The fuel rails are also subjected to quite a bit of heat, but the pump only having vapor in it and unable to pressurize liquid seems to be the real culprit. (Which is why you don't usually read about vapor lock... er, vapour lock ;) ... after they moved the fuel pumps to the fuel tanks.)

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Bill_AirJunky

I've had the problem a couple times, both times after cruising around at idle speed on really hot summer days (ie; over 95). Since then I run the blower a lot & have never had the issue again. I only have access to Regular unleaded with ethanol.

I also had the problem on a 94 MC 205. Several times I got the engine started using a cold wet rag on the fuel pump. I ended up installing a fuel line insulation kut from SkiDim.com & never had the problem again.

Edited by Bill_AirJunky

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ibelonginprison

Hopefully I can find a combination of insulated parts that help save people from having to spend $300+ to fix the issue. :)

If not, then - at least I've kept someone else from wasting their time.

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JulioEstevez

i've had vapor lock issues a few times last summer, and since then I start the blower after every solid surf sessions when we idle or stop the engine. I haven't had a vapor lock issue since... I think the blower does a very good job getting that hot air out of the oven, and there's no harm in letting it run for a good 10-15 minutes while we're floating around having a beer between riding sessions.

I know you said the heat rises and the blower may not help much, but there are maybe 10-15 cubic feet of air around the motor, and a blower seems to pump out between 120 and 250 cubic feet per minute... (http://www.westmarine.com/engine-blowers). In reality it is probably a lot less with the restriction of the blower hoses, but still !

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nyryan2001

There was a guy on here a few years back... And the insulation fix did the trick for him

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Slayer

Yeah, I like the write up too and generally agree with your assessment. I think Ryan is right. The insulation will greatly help your issues. Granted, you're in B-Ham and it gets a bit steamy there this time of year but I still think you're on to something with the insulation. I'm interested to hear what you have to say.

FWIW, I also agree with UW that they solved the issue after '04. I have an '06 with the same engine as you and have never had an issue, knock on wood. The guy I bought the boat from said it happened to him and he ended up replacing the pump thinking that was the culprit. He was living in Austin, TX at the time and had similar experiences as you. So, he put a new pump in and said the problem went away.

Looking forward to your results.

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dalt1

I fought Vapor Lock on my 06 VLX for 3 years and tried every trick in the book. I could have written the first post here. I finally sourced the Carter Low pressure pump used in the above mentioned Bakes link, Put together my own wire harness and never had another problem for the next 3 years. Had just over $100 in it. If you search Vapor lock threads from several years back, you will see my fight and solution. I guess what I am trying to say is, Bite the bullet and put the Carter pump in and be done with it.

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JulioEstevez

What do you think about putting in a second blower that pulls air in the engine compartment from the outside?

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JulioEstevez

On second thought it may send a fuel odor everywhere in the boat, probably not the best idea lol

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malibu03lxi

I have had this problem several times especially when its 85 degrees or warmer out. Just happened to me yesterday actually, I came into the dock put it on the lift for an hour for lunch, piled everyone back in and started the boat....I knew right away i had about 15 minute delay ahead of me. It usually take me 10-15 minutes with the engine cover up and blower on. When i realize this happens the engine will only run maybe 30 seconds or so before it shuts off and has no fuel. 2003 rlxi with 335 monsoon btw. Very similar situations

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Bill_AirJunky

If you have that much fuel odors or vapors, you certainly don't want them in the engine compartment.

On second thought it may send a fuel odor everywhere in the boat, probably not the best idea lol

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dalt1

What do you think about putting in a second blower that pulls air in the engine compartment from the outside?

Did that too, Blew cool air from under my starboard gunnel by cup holders directly on to the fuel pump with a second blower motor. Didn't help me.

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JulioEstevez

If you have that much fuel odors or vapors, you certainly don't want them in the engine compartment.

I was thinking of using one of the vents the vents at the rear, which would suck in exhaust fumes if the boat is idling, but doing it from the gunnels is a better alternative for my original thought.. sounds like it didnt help much though.

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Ndawg12

Definitely not fixed before 06, my monsooned vRide did it as well. Same exact circumstances as the OP, I could usually get mine to start and idle at 3-400 rpm then die after 30 seconds or so. A beach towel on the pump and nearby fuel lines, cold water bottle, and 10 minutes/1 beer later we were rolling.

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Falko

wrap your line and pump in aluminum foil after you insulate. It is amazing the amount of radiant deflection the foil will give you. I had a vapor lock issue with an old car I had. I put SS braid on the fuel line which I assume had a low emissivity, that solved the problem.

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shawndoggy

Also on an 06 don't underestimate the possibility that it's not actually vapor lock at all...

http://www.themalibucrew.com/forums/index.php?/topic/26540-vapor-lock-dead-on-the-water-for-an-hour-today/

(distinguishing factor in my case was that the boat would never stumble and die once started, it would just be REALLY hard to start when heatsoaked)

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ibelonginprison

Also on an 06 don't underestimate the possibility that it's not actually vapor lock at all...

http://www.themalibucrew.com/forums/index.php?/topic/26540-vapor-lock-dead-on-the-water-for-an-hour-today/

(distinguishing factor in my case was that the boat would never stumble and die once started, it would just be REALLY hard to start when heatsoaked)

I read your thread last weekend while i was researching, thinking it may be a similar issue - but the more I read the more the symptoms didn't line up.

Mine is always late in the afternoon after being out driving all day, hot air, bath water warm water temps, and let it sit and bake for right about an hour. The fuel pump is physically hot to the touch (not scalding, but definitely not comfortable to leave your hand on for 30 seconds.)

I can usually cool the pump down and be going in under 5 minutes flat.

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Bill_AirJunky

I was thinking of using one of the vents the vents at the rear, which would suck in exhaust fumes if the boat is idling, but doing it from the gunnels is a better alternative for my original thought.. sounds like it didnt help much though.

The factory location for the blower to vent is out the rear of the boat.

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ibelonginprison

OK - so here's an update.

I took the fuel pump out of the bracket, wrapped it once in the reflective heat insulation from thermotec that I linked in the first part of the thread. Then put it back in the bracket, and wrapped the exposed parts one more time.

Next I wrapped all the metal/hard fuel lines in the same material.

So far so good. I haven't had exact ideal scenario (95+ degree air temps, 90+ degree water temps) but I've had zero hesitation when starting after letting it heat soak for 30 minutes, 60 minutes, an hour and a half, and two hours.

Will this fix for for everyone? Dunno, doubt it. But if you're only having very occasional heat soak / vapor lock issues - it's certainly worth a shot before you spend $350 on a pre fuel pump, fuel pump kit.

I'll update in another month or so if we get a lot more hot weather coming through and I can test it out some more.

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