i have just changed my fuel pump to a walbro 255 pump and have noticed that on a full tank off 99 oct feul i only get 158miles to a tank and thats driveing like a old man.with the old standerd pump i got 250 to the tank driveing the same way. how can i sort this out and how much will it cost me?my car is also smokeing when comeing on 2 boost with black smoke is this due 2 overfueling??? my v3 sti has exhaust and induction kit and thats it.can any 1 help please dont whant my baby 2 blow againe thanks.................

 

is idle surging up and down ?

sounds like your FPR (fuel preasure regulator) is overwelmed, get an uprated one

the smoke is because of the overfueling

i use a 255 on my MY99 classic and it is ovefueling but that was the idea since i was running abit lean with a full decat, but not overfuleing to the extent you describe here and i still use the standard FPR.

hope you get it sorted

reg

 

Now may be time to get a saprk plug fitted in the exhaust

 

the idel is spot on.the boost is at 1.2bar every thing feels great just a bit concerned about the miles per gallon.any more info woud be greatfull thanks.