My turn for vapor lock

[pctkst]

Took the boat out today after work for a evening cruise and ran around for a bit with the fam and shut down to float for awhile. It was mid 80's and humid. When I went to start no luck. Looked up vapor lock online and put some cold water on the fuel pump and started it right up. Thank goodness for the iPhone.
I've read a bunch of old posts on this forum and the supra forum. Just curious what the current best approach is for a 2007 22 ssv with the 325.
Thanks.

[sandm]

'06 20ssv had the same issue. it had the 340, but basically the same motor. I found running the blower during the entire set and letting it run for 5-10 after shutdown cured the issue. even in 110deg heat, I never had the issue again. check your blower/vent hoses as well and make sure they are venting right and not pinched in the engine bay.

skiers listed a second fuel pump and some other fixes, but the blower trick worked for me and having to replace a blower a few years early is still pretty cheap compared to some other fixes I saw..

[pctkst]

This is what SC sent me. Anyone have any notes on changing the fuel filter and checking pressure?
I am 2 hours from the nearest dealer and I typically do all of my own maintenance.

I would take the boat your nearest dealer and have them check the fuel system and see the what psi your getting from the pump. They would also need to check your fuel lines and probably replace the fuel filter as it should be replaced every year. Over time fuel with ethanol can start to gum up as most boats sit with the same fuel for several months. Ethanol also reduces the boiling temp of fuel, I believe it is around 130 degrees. When you combine that with clogged filter or deteriorating fuel lines it reduces the boiling temp even more as fuel heats up quicker under more pressure. I hope this helps.

[skylar18]

Check your fuel filter first and replace if over a year old. I only had vapor lock once on my 07 and my filter was a bit gunked up

[chawk610]

Fuel Filter looks like one off a chevy... are there any "marine" differences?

[skylar18]

I don't believe so, mine come from autozone. I just replace it every year when I do my service. Got a bit lucky, the one time I did get vapor lock, I panicked, called the dealer the next day and he proposed adding a second pump for a few hundred dollars.

My mechanic at the marina said, check the cheap option first, lets look at your filter! Now change it every year, never had a problem anymore. Maybe I'm lucky but I'm glad I didn't pay for the second pump!

[chawk610]

Good advise... thanks!

[patrick232]

I have found running the blower works well on the 2007 XLV and our current 2006 LSV. One thing that that we also started doing was lifting the engine cover when docked after running the boat. Compared to other boats the air into the engine area is much less on inboard boats.

[pctkst]

Replaced the fuel filter this morning and then headed out. Did fine while wakeboarding with the blower on non stop between starting and stopping. Stopped for lunch and the problem came back. Dumped water on the fuel pump and all good. I'm starting to think I need to take another step to fix the problem. Anyone have pics of the second fuel pump setup?

[sandm]

that sucks.

iirc, it's just an inline pump between tank and fuel filter that is energized when the key is switched on. autozone/napa should be able to recommend a pump that can supply enough flow for a small block chevy motor with efi.. just have to make sure it's rated to get wet. overtons/bakes might have one as well.

[moombahighrider]

I have the two pumps on my 08 lsv an I still get vapor lock.

It's just one pump plumbed into another, both mounted on the block. The heat transfer from the block creates the vapor lock when sitting for some time after a long run.

The best way to fix it would be to replicate how the newer boats are manufactured and get a fuel pump that is mounted in the fuel tank, so it stays cooler. I suppose an inline pump that is not mounted to the block and insulated from heat would work well, provided you remove the old pumps...

[barefooterh2o]

We repair inboard boats. Usually if the pump acts up, as above, during hot weather or hot soak periods, it means a new fuel pump is in order. You can get by for a while keeping the motor box vented or pouring cold water on the pump but typically it would need replacing. The pumps that are mounted in the tank, we found fair worse than the ones mounted in the engine compartment. When the fuel in the tank is 1/4 to half and you make a sharp turns, the fuel sloshes to one side and runs the pump dry for a second or 2. Over time it also ruins the pump.

[moombahighrider]

Barefooter, I hear what you are saying but a lot of our boats (moomba/ supra) have had this problem from the get go. My boat, for example, has done this when in hot weather since I bought it new from the dealer. If I have my facts correct, skiers choice/ indmar started putting two fuel pumps in our boats from 08 until they changed to an in-tank option, to combat the vapor lock problem. None of my previous boats (stern drive) had this problem like I and a lot of guys on here experience. Now maybe the fuel pumps are just junk, but I believe it has more to do with the location that the pumps are mounted and the ability for the engine heat to affect the pump housing and fuel line.

I don't have any mechanical knowledge like you do, it's just what I have experienced and picked up from others on this forum. Also, that is an interesting point on the in-tank fuel pumps- it never would have crossed my mind as a potential concern.

[moombadaze]

When the fuel in the tank is 1/4 to half and you make a sharp turns, the fuel sloshes to one side and runs the pump dry for a second or 2. Over time it also ruins the pump. interesting, never thought about that, i'll now just make sure to never get low on fuel

[parrothd]

Same with running your car on empty, shortens the life..

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[rdlangston13]

We repair inboard boats. Usually if the pump acts up, as above, during hot weather or hot soak periods, it means a new fuel pump is in order. You can get by for a while keeping the motor box vented or pouring cold water on the pump but typically it would need replacing. The pumps that are mounted in the tank, we found fair worse than the ones mounted in the engine compartment. When the fuel in the tank is 1/4 to half and you make a sharp turns, the fuel sloshes to one side and runs the pump dry for a second or 2. Over time it also ruins the pump.

wouldnt this happen to a pump that is not located in the tank too? i mean regardless of pump location in a sharp turn if the fuel gets away from the pickup then the pump will cavitate. I would think the pump would have a harder time regaining prime the farther it is away from the fuel source. All modern fuel injected cars have their pumps in the tanks and I have never heard of problems in cornering situations

[moombahighrider]

I was wondering/ thinking the same thing, David.

[parrothd]

Google it..

http://news.consumerreports.org/cars/2011/05/running-on-empty-low-gas-in-the-tank-can-be-costly.html

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[rdlangston13]

Google it..

http://news.consumerreports.org/cars/2011/05/running-on-empty-low-gas-in-the-tank-can-be-costly.html

Sent from my Nexus 4 using Tapatalk 2

My argument is not that cavitation is not bad for a pump, cavitation IS bad, I just do not see how a pump mounted directly at the fuel source could fair worse than one mounted say 5-6 feet away. I have also heard about pouring cold fuel from service station on a hot fuel pump that has not been submerged in fuel due to running the tank real low causing the magnets in the pump motor to crack, thus making the pump inoperable. In either case it is an unlikely scenario and I would say even less likely on a boat due to the fact that it is used far less than a car.

[sandm]

I know guys that autocross their cars every weekend all summer long. in an effort to save weight, they run with bare minimums of fuel and are not experiencing any greater failure rate in fuel pumps. this in a car that's getting tossed all over a short-coned track.

I agree with moombahighrider in that the supra I had experienced vapor lock for the last time in '08. after running the blower(and, not thinking about it, replacing the fuel filter every spring starting in '09) I never had an issue again and never replaced the pump, so I'm not sure that a faulty pump is the culprit. my experience, after being left stranded at a gas station in Price Utah on vacation are that pumps either work or don't.

[NCSUmoomba]

Maybe it is just good luck, but the fix I did is easier than all of that. My boat vapor locked a couple of times, very aggravating, and I do change the filter every year. (I have the spin-on type.) I started putting Sta-Bil Marine Ethanol treatment in my tank EVERY time I get gas, and have never had another problem. As some of the posts above refer to the ethanol lowering the boiling point of the fuel, the fuel treatment seems to solve this.

I seem to be killing two birds with one stone, no vapor locking, and preventing the harmful effects of running ethanol.

[maxpower220]

Most every fuel tank has a baffle around the pickup to reduce the chance of fuel starvation. Unless you sustain a turn, the pump should not run out of fuel at the pickup (nor should your car). Sure, it can happen.

[skylar18]

Maybe it is just good luck, but the fix I did is easier than all of that. My boat vapor locked a couple of times, very aggravating, and I do change the filter every year. (I have the spin-on type.) I started putting Sta-Bil Marine Ethanol treatment in my tank EVERY time I get gas, and have never had another problem. As some of the posts above refer to the ethanol lowering the boiling point of the fuel, the fuel treatment seems to solve this.

I seem to be killing two birds with one stone, no vapor locking, and preventing the harmful effects of running ethanol.

I also use marine sta-Bil everytime I fill up with fuel. My dealer sent an email to us about three years ago suggesting that we do that.