excessive fuel consumption

koziolek · Post by **koziolek** » 02 Sep 2010, 20:12

i have 1997 850 its 20 valve non turbo
and I think its take to much fuel
i cant go lower than 11L per 100km on HWY
everything looks ok
no check engine light,
new distributor cup
new rotor
new wire
pvc system done 15 000 km ago
new spark plugs
wheel alignment done
any clue?
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Post by **jblackburn** » 02 Sep 2010, 20:54

Could be several things...but I would start at the fuel pressure regulator. If you disconnect the vacuum line, it should be DRY and not smell of gas.

Other things could cause it as well - my gas mileage kept declining until I replaced an O2 sensor. A dirty MAF sensor can do it as well, as well as a vacuum or exhaust leak before the O2 sensors.

koziolek · Post by **koziolek** » 03 Sep 2010, 20:47

passed emission test in flying colors
so I thing O2 sensor should be fine

valvster · Post by **valvster** » 04 Sep 2010, 05:15

I did the airbox mod
https://www.matthewsvolvosite.com/forums ... php?t=8830
and noticed an improvement in fuel consumption measured by the hip pocket, sadly my odometer doesn't work so I can't verify it. Definately improved acceleration and eliminated a flat spot, just be aware of reports of sticking throttles in colder climates....not a problem in Oz but.
Best I got when car was newer and odometer worked was10.5L/100Km.

Valvster