Just re-fitted my fuel tank and fitted a new o-ring and have now got fuel bubbling out from around the cradle where the new o-ring is.
I believe it is also causing a mis-fire when coming on to boost.
Any ideas???
I going to check the o-ring is seated correctly in a bit.
Is the fuel tank full? I didn't know the fuel went that far up in the tank, assumed it would have clicked off before that?
No there's only a jerry can full in there lol.
It's very strange
Not been doing any acrobatics?
If the top of the tank was dry when you fitted the O ring and pump it suggests you have a leak on the short hose that fits between pump and cradle. Or a crack in the top of the pump. That will spray fuel over the joint and then if not properly fitted it may leak.
Nope no acrobatics here!!
I have just taken the pump cradle back out and no visible leaks on the short hose between pump and cradle. (I tightened the hose clamps a little more)
If i put my finger over the pump outlet on top of the cradle and switch pump on should it build pressure? (I guess not as their is no fuel in the pump).
The o-ring was seated correctly and none of the bolts have pierced into the tank.
sounds like something is causing back pressure in the tank. Have you checked your fuel lines are not blocked or connected the right way?
What would cause back pressure in the tank though?
The fuel lines are the correct way around i have checked this evening!
Is there a check valve?
Either way doesnt explain how it would leak from around the top of the tank
I just remembered about the fuel tank breather on the filler neck. That should let out any pressure from the tank from the fuel return hose. Mabye see if that is blocked.
That's not the breather i dont think! And the tank is meant to be pressurised slightly hence the whoosh when you open the filler cap!
It's not I was too tired, that pipe is the vacuum relief line, there is a check valve also
There might be some kind of check valve inside the tank incase you roll the car, I don't know though. Can't see that being the problem anyway.
Large bore vent between high point on tank and filler neck allows high point to fill. It also "burps" petrol out down the side of the car when you try to brim it.
Check valve on breather hose is bolted to underside of car near the diff oil cooler, Page EF&EC-133. It lets air in easily to stop tank being sucked flat but lets fuel vapour out against more resistance.
On lambda equipped cars it has a line that goes forward along the fuel lines to the carbon can.
On non lambda cars it just vents though a short hose.
Tank cap also has "gulp" valve, test also on Page EF&EC-133.
Only reason for it too have 2 suction relief systems I can think of is in case one sticks shut or is blocked.
The fuel pump is page FE-3.
try unscrewing the filler cap so its loose, then see if you have the same problem.
With filler cap loose it seems ok!Originally Posted by green_rs13
Out on track at coombe after a 15min session i opened the boot and noticed bubbling from the cradle only in one place.
The o-ring is seated correctly, no splits in the hose from pump to cradle and no splits/holes in pipework on the cradle.
Really odd as the tank was only quarter full at this point!
My fuel tank has a pipe that goes to the carbon canister at front to vent you defiantly have pressure in your tank buddy
My car is pre-facelift = no carbon canister.
But it does appear the tank is pressurising some how
Do you have the right length screws? Are they bottoming before they clamp the flange on to the O ring?
You would think that taking fuel out of the tank would reduce pressure. The tank will pressurise, fuel gets warm on its trip though the pump and engine bay, vapour pressure increases by more than the liquid fuel used. The tank vent valve has a high resistance to burping nasty hydrocarbon vapour into the air or down the pipe to a carbon can. It will suck air much easier.
4 of the 6 screws are slightly longer by a few mm maybe as the oem ones had stripped threads!
They clamp down tight though but am trying to find some decent quality replacements.
I just cant understand how it would be fuel bubbling out especially as tank is only quarter full!
I'm just wondering if there is a split in the pipe which sucks up the fuel and is maybe spraying it at the underside of the fuel pump where the seal is?
I have checked this visually but obviously that is under zero pressure.
Not sure how i can test it without it being in the tank as dont really wanna spray fuel everywhere.
Oh and when i noticed the bubbling at combe the engine was switched off. So confused
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