fuel tank air lock ???

[Bagdad mafia]

Hey fellas, just got my rig going for the first trip out after a major upgrade and have a slight issue.


I have installed a 165l alloy fuel tank in the rear of my 4runner feeding a holden 5l with 3 inline filters,

After a day out wheeling about 1.5km from home it started to feel sluggish and unresponsive as if starving of fuel then just as i got home it seemed to run out of fuel in the street out the front of home

After winding it over a few time more times usual it fired up and went fine.

The new tank has no breather and when i checked it out this morning it wasnt low on fuel (over half a tank) and all filters seemed ok but when i opened the filled cap it seemed to have quiet a lot of vacuum into the tank.

Could this be an air lock and starving lift and pressure pumps there for loss of fuel pressure and starving for fuel ?

Could this be my problem ?

Any ideas ?

What sort of breather set up do others ue on cutom tanks ?

All thing considered new 4by went well and made it home under its own s
team.


Thanks Gav.

[chunks]

Sounds deadly. Who made the tank? I would be concerned about the quality of it if it has no breather, what happens on a hot day when pressure builds up in the tank due to fuel vapour?

[Bagdad mafia]

Tank was made by a mate that builds tanks for boats and built to survey specs, no biggy to fit a breather just after feed back on what kind of breather works best.

[Bumpy45]

Tank was made by a mate that builds tanks for boats and built to survey specs, no biggy to fit a breather just after feed back on what kind of breather works best.

I had 3 filters in my system when I got the truck and removed two of them. If you consider that when the first one after the tank is blocked then no fuel flows to the other 2. Ypu could have a filter after the tank and then one between the pump and carby.

As for the tank I would have thought that there was an existing breather system in the truck that you could tap into. Most likely around the original tank. I don't have a runner so I am not too sure of the exact setup.

By the way, what thickness is the tank and how many baffles?

[Bagdad mafia]

i have one filter before the lift pump one on tehe line from lift pump and one high pressure in the engine bay all seemed tho be ok,

Main reason for the 2 filters before the high pressure pump is to filter out any alloy that could still be floating around in the tank.

The tank has a 6mm bottom and 4mm sides and top with 3 baffles. holds 165l all up

[Kitika]

Have you tried driving with the cap loose? If that doesn't work I'd say it could be cavitation from all the filters or is your lift pump feeding straight into the high pressure pump? That could also be causing cavitation/vapour lock when it heats up a little bit.