My '84DL has suddenly given me problems with starting when it is warm (after
driving a few miles) or when the engine is a normal operating temperature.
Cold start is fine although the idle is slightly rough.  Fuel economy has
taken a nose-dive.  If I drive the 12 miles to work (last 5 Interstate), and
turn the engine off, it will not restart without much cranking and the
accelerator pedal almost floored.  While cranking, the engine will begin to
catch and then finally take off.

I had my mechanic do a tune-up in June and he recently replaced fuel lines
and injectors.  Until this new problem started, I was having problem with
fast idle after warm-up and have idle stabilizer and aux.. air regulator on
order.

Any thoughts on what to check first?

John Lauterbach