Poor Gas Milage on a 1983 528e 5 speed

[Pamela Crossett & David Wolf <agraphic@xxxxxxxxxxxx>]

I have a 1983 528e 5 speed transmission that used to get 22-23mpg in my usual
city driving and almost 30mpg on the highway (I've owned the car for a year
and a half). But for the last four months, my milage has mysteriously dropped
to 17mpg city driving and not much better, maybe 20mpg on a long trip. The
engine was rebuilt by previous owner 4 years ago. 

My friend who maintains the car is mystified, he's checked the following and says:
1) spark plugs look good
2) there appears to be no leaks on the intake manifold
3) resistance of temperature sensor input to the ECU appears to be within book value
4) voltage output from oxygen sensor appears to be within book value

Does anyone out there out there have any ideas of what to check? Or have the
answer? An answer? Help, please!

TIA

Pamela Crossett
1983 528e 280,000+ km 






Pamela Crossett                             Mailto:agraphic@domain.elided

          http://www.nikken.com/pages/774166700/

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