Hard start '88 90q

[work]

    when cold (not outside temp, but engine temp) my car is hard to start
and then dies after i drive one city block and stop at the stop sign.
otherwise it runs perfectly fine: it starts when warm and doesn't die except
for that first time, maybe at the second stop too, but otherwise just fine.
my mechanic, for unrelated necessary reasons, replaced the fuel lines and
then performed a tune-up in an attempt to fix this problem.  here's what
i've figured out:
        1.  if you pump the gas pedal two or three times before starting and
then pump it once or so while cranking, it starts up,
        2.  if you don't do the above, it starts reliably the second try.
please help, i think my mechanics next option is to just start replacing
things which sounds kind of expensive.
    unrelated question, i drive only in the city and only a single 3 mile
trip to work (i take it out on the highways on the weekends for real
drives), but what is your gas mileage for weekly commutes like this?  mine
is maybe 16 mpg.  thanks, bryan.