had a problem at the river couple weeks ago boat overheated and then also seemed to run out of gas. replaced the impellar fixed overheating problem. checked the gas tank it was full so then hit the valve on the fuel rail had a little air come out then fuel took it to two mechanics one said fule pumps went bad other said had no idea. after taking the gas cap off and pushing the fuel rail valve till fuel came out boat started and ran good. friends boss said it probably vapor locked which would make sense it was 123 out and motor overheated. now this weekend boat running 160dg not overheating and outsie temp was 100 boat runs great for two days then does the same thing sounds like running out of gas then dies at idle. open gas cap and hit the fuel rail valve start boat runs great rest of weekend. anybody have any ideas boat ran fine up until these last two trips
454 mercruiser running problem
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it is a 2000
Well It could be the fuel pick up tube is broke or cracked in side the gas tank, If it is doing it while the fuel tank is low on fuel After 2 days of running. Or could be a cloged up vent hole between the tank and the vent. Might want to check the fuel in the filter and look for anything like dirt, water, ect., And put a new one on to be safe. Also It does kind of sound like fuel vapor lock. Open this link and find the year 99 on the left side and open it, then open and read number 99-7. http://www.boatfix.com/merc/Bullet/sbcover.pdf. This will help you understand fuel vapor lock if you want to know more about it.
my buddies thought was the fuel pickup but ran after i opened the gas cap and purged the fuel system and then kept running with no problems. i can see it vapor locking at the river in the heat plus the motor overheating. not at naciemento it was not as hot outside and the motor was running cool. could it be possible that maybe the breather vent is clogged on the gas tank? but then i would think when you opened the gas cap you would hear the pressure release?
maybe it is time for a new boat
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2,046 Posts
My old Howard acted this way and I found out it had vapor locked.
I only had one fuel pump on the engine that sucked from both tanks. I ended up adding a fuel pump from the tanks to the high pressure pump on the engine and everything was better.
I found out Mercury knew about the problem and even sells a kit for this problem.
One Marine Holly Fuel Pump solved my problem!
I only had one fuel pump on the engine that sucked from both tanks. I ended up adding a fuel pump from the tanks to the high pressure pump on the engine and everything was better.
I found out Mercury knew about the problem and even sells a kit for this problem.
One Marine Holly Fuel Pump solved my problem!
Do you know where your vent is? As long as the vent is not hooked to the gas fill, And it has it's own vent on the side of the boat you could blow a little air into the fuel fill and see if you get air out the vent. You can get vapor locking just about anywhere, Does your fuel filter still have the black plastic cover over the filter, That is is designed to help keep the fuel in the filter cooler. Also keep in mind you could have some splinters in side the fuel hose itself, And that would make air bubbles in the fuel as the the fuel flowed thru the hose, Letting in air to the system.
bulb
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2,046 Posts
My boat vapor locked at 118 D with a little over half a tank of gas.
1. When I shut it down it would not start. Sea Tow guy came buy and explained to me the problems he has seen.
He told me about some boats were vapor locking on hot hot day. He said he has seen boats with and without low pressure fuel pumps. The boats that did not have a low pressure fuel pump were the ones that were vapor locking.
Does your boat have a low pressure fuel pump that feeds the high pressure injector pump?
Variables
1. Gas Tank location
2. Engine location (how high in relation to the gas tanks)
3. Gas line (how they ran it
4. Outside temp
5. Gas tank level
6. Engine compartment vents (cool air)
1. When I shut it down it would not start. Sea Tow guy came buy and explained to me the problems he has seen.
He told me about some boats were vapor locking on hot hot day. He said he has seen boats with and without low pressure fuel pumps. The boats that did not have a low pressure fuel pump were the ones that were vapor locking.
Does your boat have a low pressure fuel pump that feeds the high pressure injector pump?
Variables
1. Gas Tank location
2. Engine location (how high in relation to the gas tanks)
3. Gas line (how they ran it
4. Outside temp
5. Gas tank level
6. Engine compartment vents (cool air)
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