2001 Volvo 5.7GS PEFS hot run issue; Vapor Lock?

[joebrown]

I have a 2001 Four winns with a 5.7 carburated motor. This issue I am having started last year and is now doing it again. Last July at Table Rock lake, I took a drive for about 30 minutes. We stopped to swim in a nice cove for about an hour. Started the boat back up, and hit the gas. Once it started to go, the boat died. We had to sit there for about 2-3 hours before it would start again. Once I started it again, it ran like a champ. This same thing has happened various times since the summer of 07. It just happened again last weekend. Fuel pump, or is my Captains call causing too much heat and vapor locking? I think its vapor locking myself. Any help on how to correct this issue is greatly appreciated!

S/N :4012046425

 

[Don S]

Re: 2001 Volvo 5.7GS PEFS hot run issue; Vapor Lock?

How hot does it get in the engine compartment? Have you tried to leave the blower on or open the hatch to cool it down if it's really hot?

 

[joebrown]

Re: 2001 Volvo 5.7GS PEFS hot run issue; Vapor Lock?

I am not sure really, because by the time the lid is up (hydrolic) all the ambient air is gone. I was told to run the blower when the boat is on, and also told to keep the hatch open when we are still. No avail. It has only happened in Jul and beyond both last year and this year. Each time it happened, outside temps were well over 90 degrees. My manifold is hot to the touch, and the engine is producing a bunch of heat, but the temp gauge is right on.

 

[Don S]

Re: 2001 Volvo 5.7GS PEFS hot run issue; Vapor Lock?

When was the last impeller change, how hot is you engine running.
When it's over 90 out, then things do heat up in the engine compartment. May need to just open it up a little when you can, or leave the blower on to circulate the air while stopped.

 

[joebrown]

Re: 2001 Volvo 5.7GS PEFS hot run issue; Vapor Lock?

Impellor was changed in the fal of 2006. Since it does get so hot here in Oklahoma, typical to see 100 for weeks straight, do you think it would help to insulate my fuel lines with the heat shield products? I really do think it is vapor lock, but never experienced it before. How about adding some inflow vents to the side of the boat also? Good or not worth it?

 

[Don S]

Re: 2001 Volvo 5.7GS PEFS hot run issue; Vapor Lock?

Try opening the hatch a little when you stop, and see if that cures the problem. If it does, then you have a direction to go for the cure.

 

[Eliminator]

Re: 2001 Volvo 5.7GS PEFS hot run issue; Vapor Lock?

I live in the great white north and I noticed while my engine temp never gets over 180, I can come back 2 hours later and start it up and the gauge shows 130-140 on a 90 degree day? That's just coolant temp, block temp was 150 higher than that when you shut off so things have to equalize. Doesn't surprise me that the fuel pump diaphragms might be surrounded by vapor.

 

[joebrown]

Re: 2001 Volvo 5.7GS PEFS hot run issue; Vapor Lock?

I took it out yesterday and it did it again. I opened the lid when resting, let it idle for 5 minutes before shutting it off. Checked fule pump when I got home. It works fine. I am lost here.

 

[Tail_Gunner]

Re: 2001 Volvo 5.7GS PEFS hot run issue; Vapor Lock?

Id check the impeller again....i had a badly worn impeller after 50 hours factory installed...Chunk's missing on 5 or 7 of the vanes....i also have a 1993 that i inherited...looking at the service records it had never been done...the owner had no ideal what i was referring to...The impeller was perfect...i dont believe there is any general rule for life expectancy...they live in a pretty busy enviroment...

You could always check the thermostat or replace with a 160 degree cheap maintance.. If those two are good....and the motor does run for 20 minutes at a even 160-175 you may just a bad starter...or a timing advance issue..id bet its a temp problem

 

[Eliminator]

Re: 2001 Volvo 5.7GS PEFS hot run issue; Vapor Lock?

When it won't start look down the carb and operate the throttle, if you have nice STREAMS of gas squirting in and it still won't fire it shouldn't be vapor lock. Did you check for spark when it wouldn't start?

 

[2003lsr]

Re: 2001 Volvo 5.7GS PEFS hot run issue; Vapor Lock?

Joebrown, first get a peice of wire 5 or 6 inches long, strip the ends, and put it in your boat glove box. If the no-start occurs again, remove the fuel pump relay and jump terminals 30 and 87 (with key in off position). You should hear the fuel pump run and the float bowl filling up. Let the fuel pump operate for a few seconds or so, then remove the jumper wire and reinstall the relay. Start the motor and hopefully it gets you on your way to having a day of fun again. It seems that for some reason the fuel pump is unable to pump fuel into the fuel bowl, and the motor stalls once the bowl is empty. Possibly vaporlock from the fuel lines heating up? I think your idea of insulating the fuel lines is a good one. Please keep us posted on your progress.