Greetings all.

I have been noticing that my van runs better on a full tank down to
about half a tank. When running on less than half a tank of fuel the van
tends to run rougher. As far as I know there is no water in the tank,
the fuel filter last time I took it off was clean as a whistle inside (
cut it in half, then installed a new one). I always use Chevron gas with
techroline. This is not a one of, it has been going on for 20,000 km. I
was wondering if there is some sort of gravity feed to the fuel pump,
full tank providing more pressure to perhaps a weakened fuel pump ?
Sounds foolish I know. Anyone have thoughts on this? Also, last reading
of fuel pump pressure, it pumped the required amount fuel into a
container over 30 seconds.
--
R.Feuerriegel
88 syncro