problem solved

most of the time when installing a new aftermarket fuel pump it always make the car run alot more richer ratio's meaning that the car will make lesser power however once these are fixed with the installation of a ecu, u should be set

A powerful aftermarket pump can sometimes increases the pressure in the fuel lines and therefore force more fuel past the injectors. This causes the mixtures to run a little richer and hence a small sacrifice in overall engine output results.

Although I would of thought that the "advanced" (Stubborn) ECU in the 04 WRX would have compensated for this.

ECUTEK tune will most likely fix this.

Are you sure it was a WALBRO pump? Did it have WALBRO etched onto the side of the pump? There are alot of china spec's going around which claim they are walbro...

Id suggest removing it, and fitting something like a bosch 910 or 040.

My Walbro is also starting to shit itself

You should not need a retune for a drop in pump. I ran my so called walbro on the stock ecu for a long time with no problems.

Did you fit the stock teabag? or the smaller one that usually comes with them?

I would have thought that whatever pressure your fuel pump is feeding the fuel, once it gets to the fuel regulator it will be reduced to whatever pressure the fuel regulator is meant hold, isn't that the whole purpose of a fuel regulator in the first place?

^^^^ thats right

Yes its a Walbro, it had Walbro etched on the side, I also fitted the small tea bag and the wiring loom as the fitting instructions recommended. I will give Maxium Motor Sports a ring to see if this is what is to be expected.

Thanks for all the replies

i would leave the stock teabag mate.... u gonna run into a million and one problems

yep thats probably your problem. Take it out again - and fit your stock (larger) teabag on

Yup, thats your prob....put the stock fuel sock back in and she'll be sweet!