- Parts Required
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walbro 255 fuel pump
after fitting a supercharger to my z22se the were needs to fit an uprated fuel pump
here is how to fit a walbro 255 pump into the standard tank holder of an astra G
first off you will need to remove the lower half of the rear seat bench
this can be done by lifting it up vertical and tapping the locking wires out the holers
once the rear bench is removed you will see a round cut out in the carpet heres where the pump lies

under the carpet there is a weather seal / plastic cover it can be remove by popping it out with a screwdriver

now the cover is removed you will see the top of the tank and the pump top

disconnect the plug from its socket by lifting the tab then remove both fuel lines there the same fittings that are on the fuel filter (2 tab at either side) push the tabs in and slide off keep a rag handy to catch any spilt fuel

the pump top is held in place by a metal lock ring that will require some work with a hammer and chisel be sure to clean any debris or dust from the surrounding area before removing the pump top from the tank
i found it easiest to tackle the lock ring in an anti clockwise direction and putting the chisel at the front as there was more room for the hammer

with the lock ring removed give it a quick clean up again and blow the dust away

now you can lift the pump top from the tank unplug the pump this will give you a little more freedom to move the top out the way

the pump cage is held into the tank with 3 tangs you can see one of them by my little finger

you should now beable to lift the pump clear of the tank watch out for fuel in the pump
there is one pipe on top of the pump the clip will have to be parted with a screw driver its then just a case of sliding the pipe off

the pump and cage with now be free from the car
the cage has a top support thats held in with self locking tabs in 3 places unclip them and lift the cage top off


the bottom of the pump cage has a filter pushed on to the pump held in with a washer i found it best to prize the washer up with a screwdriver to save damage to the filter

the pump will now be free of the cage

here you can see the filter is quite dirty

the walbro pump is slightly larger in diameter and longer in length this is where you will need to modify the pump cage to get the new pump to fit in
the lower half of the cage there are 5-6 ridges than need cutting down it is a trial and error process

the top part of the cage is a little more time consuming and requires more material to be removed again this is a trial and error fit try not to take too much away
the ridges on the inside need taking down and the top ring cutting back about 10mm

here you can see what's left of the top ring this was enough to get the top and pump in the cage and locked down


the new pump in the modified cage dont forget to refit the lower filter after cleaning it up it just pushes on be sure the peg goes in the hole with the washer

refit the fuel pipe and pipe clip i used wire cutter to clamp it back shut
drop the pump back into the tank swirl pot and reattach the wiring plug to the pump

clean all the dust and bits off the top lip of the green tank seal then place the pump top back down over the hole refit the metal lock ring and tap back clockwise so it secures the pump top
reconnet the fuel lines and the pump plug

pop the cover back in and drop the carpet refit the rear seat bench then go test your work

turn your ignition on and let the pump prime 2-3 times before starting the engine this will push air out of the fuel lines and fuel rail
i was able to test the pressure in the fuel line with a set of refrigeration gauges to make sure all was well the fuel pressure regulator is fixed at 3 bar with the engine running thats what i got

here is how to fit a walbro 255 pump into the standard tank holder of an astra G
first off you will need to remove the lower half of the rear seat bench
this can be done by lifting it up vertical and tapping the locking wires out the holers
once the rear bench is removed you will see a round cut out in the carpet heres where the pump lies

under the carpet there is a weather seal / plastic cover it can be remove by popping it out with a screwdriver

now the cover is removed you will see the top of the tank and the pump top

disconnect the plug from its socket by lifting the tab then remove both fuel lines there the same fittings that are on the fuel filter (2 tab at either side) push the tabs in and slide off keep a rag handy to catch any spilt fuel

the pump top is held in place by a metal lock ring that will require some work with a hammer and chisel be sure to clean any debris or dust from the surrounding area before removing the pump top from the tank

i found it easiest to tackle the lock ring in an anti clockwise direction and putting the chisel at the front as there was more room for the hammer

with the lock ring removed give it a quick clean up again and blow the dust away

now you can lift the pump top from the tank unplug the pump this will give you a little more freedom to move the top out the way

the pump cage is held into the tank with 3 tangs you can see one of them by my little finger

you should now beable to lift the pump clear of the tank watch out for fuel in the pump
there is one pipe on top of the pump the clip will have to be parted with a screw driver its then just a case of sliding the pipe off

the pump and cage with now be free from the car
the cage has a top support thats held in with self locking tabs in 3 places unclip them and lift the cage top off


the bottom of the pump cage has a filter pushed on to the pump held in with a washer i found it best to prize the washer up with a screwdriver to save damage to the filter

the pump will now be free of the cage

here you can see the filter is quite dirty

the walbro pump is slightly larger in diameter and longer in length this is where you will need to modify the pump cage to get the new pump to fit in
the lower half of the cage there are 5-6 ridges than need cutting down it is a trial and error process

the top part of the cage is a little more time consuming and requires more material to be removed again this is a trial and error fit try not to take too much away
the ridges on the inside need taking down and the top ring cutting back about 10mm

here you can see what's left of the top ring this was enough to get the top and pump in the cage and locked down


the new pump in the modified cage dont forget to refit the lower filter after cleaning it up it just pushes on be sure the peg goes in the hole with the washer

refit the fuel pipe and pipe clip i used wire cutter to clamp it back shut
drop the pump back into the tank swirl pot and reattach the wiring plug to the pump

clean all the dust and bits off the top lip of the green tank seal then place the pump top back down over the hole refit the metal lock ring and tap back clockwise so it secures the pump top
reconnet the fuel lines and the pump plug

pop the cover back in and drop the carpet refit the rear seat bench then go test your work

turn your ignition on and let the pump prime 2-3 times before starting the engine this will push air out of the fuel lines and fuel rail
i was able to test the pressure in the fuel line with a set of refrigeration gauges to make sure all was well the fuel pressure regulator is fixed at 3 bar with the engine running thats what i got
