Reply With Quotenot on a boat...only on an old truck I had...
This last weekend out at Havasu my 454 Magnum vapor locked on me. Any one of you had this problem befor???????????????
not on a boat...only on an old truck I had...
I had the same problem with my 454 Mag. None of the service centers could solve the problem. We finally put a Whipple Charger on the motor - problem solved.
Aside from that, I was told to depress the Schrader valve (bicycle tire valve) on the fuel rail to release any air bubbles. Once the gas starts to flow out of the valve, stop the process and wipe up any spill. Try the motor and see what happens.
I tried all of the other things...wait for a few minutes, etc, etc...none of them worked. Try the valve and let me know if it helps. Luckily we got rid of the POS Mercruiser fuel injection and the problem.
Does anybody know why Mercruiser put the fuel cooler right next to the engine block? That doesn't seem to be a very cool spot.
In regards to the fuel pump "pushing" the bubble out, I have two batteries sitting in the garage that I burned out cranking the motor over and over again. The vapor lock happened nearly everytime the engine was run hard.
[ August 12, 2003, 02:00 PM: Message edited by: NOCTURNAL ]
Yes the gas/water seperator is located right next to the exaust and it has a cool can (plastic) that goes around the can filter. After the vapor lock I removed the gas/water filter and put it back on and the boat started. This is the first time this has happened. A friend of mine Dennis tells me that he heard that certain year 454 Mercury engines only have a electric fuel pump and no mechanical pump. He heard these engines will vapor lock.
A friend just sent a Mercury Bullitin that talks about the vapor lock problems. The bullitin explains that the hot engine compartment can cause the vapor lock. The make a kit that will help the situation.
Try a wooden clothes pin on the fuel line that runs from the cooler to the fuel rail
old trick from the days before fuel injection
and carbureted engines ...
but to tell you the truth fuel injected engines dont vapor lock im not sure if yours is or not if it is there might be something else causing the problem
My HP500 does it when its really hot out.After sitting for long periods of time at the sand bar or on shore it will do it.Leave the engine hatch open alittle when parked and it will help.I put a damp towel on the intake if the hatch has to be shut for awhile.
When it is really hot try to keep lots of fuel in the tanks. EFI recycles the fuel back to the tanks. When the fuel is low that little bit of fuel makes more round trips threw the fuel pump and the hot injector system. Making the fuel in the tank even hotter. My friends 38 Formula had this problem. He said that was a recall from Mercury to fix vapor lock.
Funny I thought it was just my engine!
My 502 mag did that this weekend for the first time. Everything in the engine compartment was HOT! After I let it sit about 10 minutes with the hatch open and me dripping sweat and alot of trying it started up and drove fine the rest of the weekend!
The fuel system you guys have probably recirculates the fuel. I had a car that had this problem and all of my friends had the same problem with their cars. The fuel will sit in the fuel rail and get WAY to hot and the motor just wont fire up. Best thing to do was to open the hood and let some of the heat vent out but sometimes I would get stuck at the gas station for 15-20 minutes on a hot day. I tried sticking ice on the fuel rail but it never seemed to help out any.
[ August 14, 2003, 11:04 AM: Message edited by: Boozer ]
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