vapor lock? how do I fix this?

[jposowski]

I think my b-mod is vaporlocking. It ran great until the middle of the feature under caution it spudders and dies, and they push me off. I checked the vent, filter, and the pump works good 7 psi. After being pushed to the pits, I put air pressure to the vent for a few seconds, and then it starts. Does anyone have any ideas of what the issue may be?

[ford396]

If it is in fact vapor locking, meaning the gasoline is vaporizing in the fuel line; it would be beneficial to ensure that the lines are as far away from the exhaust as possible and to install heat wrap on the lines. Anything that you can do to reduce the temp of the fuel will help offset the engine heat that is being absorbed into the line and fuel.

I am sure that there will be more ideas to come, but keeping the lines cool will be a step in the correct direction.

[Graff Spee]

They also have a heat shield for under the carb. I saw a guy once run a trans cooler in the fuel line just before the carb. It worked but I would not recomend that!!!! LOL

[jposowski]

Thanks for ideas guys, I'm doing a thorough inspection of the gas tank, lines and pump. I'll try insulate the fuel lines by the engine. I've ran this car 4 races before and havent had a problem until now, weird. I suppose it is getting hotter out tho.

[cheaterleaddog]

vapor lock

Run a bypass return system either with a secondary pressure regulator set a little below your pump pressure so that the extra fuel not needed is returned to tank. the other way is to install a orfice [.050 will be enough] in the return line and a valve that is hooked to throttle so that when at w.o.t. the valve is closed and when off throttle valve is open and returning fuel to tank. either way will work keeps fuel moving so that fuel does not set still by the heat source will even work to lower fuel temps if not having vapor lock problems and cold fuel equals more dense fuel I like the valve and orfice best but it is harder to do. and if your a cheater it will give the tech guys something else to look at, a little bait and a little jigging and they'll usally bite

[stock car driver]

Ive seen an awfull lot of cars with oem fuel pumps steel line to the carb etc. I seriously doubt your vapor locking. You could have something over the pick up in your cell, the pick up above the foam, the pick up line loose in the cell, the pick up line collapsing....

All are suspect on my list before vapor locking.

[Graff Spee]

We had a fuel cell pick up line that was cut at an angle so it would neverget blocked. Well it just happen to be the perfect angle to suck flat against the inside of the fuel cell! Engine would sputter at odd times and lose power. We found the line on accident. Fixed everything!

[Chico]

also could have a pin hole in the pick up