High Fuel Consumption 1989 325i

[gib1son]

The fuel consumption on my 1989 325i has increased by 25 percent.
It runs fine, but the exhaust smells very rich, like a car from
the 60's. The O2 sensor is new, the mass airflow sensor was changed
a few months ago, and the fuel pump is new. Any help much appreciated.
Is there a throttle position sensor that got bumped or something?
gib1son

 

[bahnstormer]

check the spark plugs
and the injectors...are they stuck open?

there are companies that will flow test your
injectors and rebuild them

 

[bad ass v-dub]

I had problems with fuel consumption after I got a new o2 sensor. it ended up being the fuel pressure regulator.

 

[epj3]

What kind of gas mileage are you getting? If it's around 25 - 30 highway then you don't have anything to worry about, all M20's smell bad when doing around-town stuff.

 

[gib1son]

Hi Eric, it's about 18mpg. It did get 25mpg on highway but dropped after
having some work. the mass airflow sensor was changed. Since posting
the original message, I've found some info on checking the different sensors.
Thanks

 

[epj3]

Hmm you should get around 18 city and 26 - 30 highway.

 

[gib1son]

Fuel consumption fixed

I found the problem to be the mass airflow sensor. The vane
was sticking. Snapped it back and forth a few times and
it made a dramatic difference in fuel consumption. Thanks