Saab Link Forums banner
1 - 8 of 8 Posts

·
Registered
Joined
·
3,998 Posts
Discussion Starter · #1 ·
Last year I swapped in a Walbro 255HP into the fuel tank, after the stock pump died. Since then, I've been getting shit mileage(20mpg @ 75mph with or without AC). I've tried all of the usual suspects (o2 sensor, temp sensor, readapting, different DI cassette, etc). I don't see why replacing the fuel pump would cause the mileage drop(if I do 55mph i get ~25mpg), so I'm not really sure what else it could be? I've checked for leaks, and there are none that I can find.

Any thoughts?
 

·
Registered
Joined
·
10,049 Posts
You ever replace the fuel filter? After a fuel pump job - sometimes debris can get stirred up and clogg a filter... poor flow usually results in poor performance more so then fuel economy however. Still something to consider. Have you tried a fuel system cleaner?
 

·
Registered
Joined
·
3,998 Posts
Discussion Starter · #4 ·
yeah, thats what the SID reports. i calculate mileage every time i fill up, and the SID is within 1/2mpg every time.

bs42: yeah, fuel filter was replaced, and i've tried a couple fuel system cleaners with no luck
 

·
Registered
Joined
·
13,686 Posts
Did you partially pinch the return line so that the rail pressure is too high? What do the fuel trims look like?
This is what I was going to suggest after finding this issue in my 9-3 when I replaced the pump. Fuel milage has gone back to normal since fixing that issue, but before it would be around 20mpg all the time, no matter what.
 
1 - 8 of 8 Posts
Top