Where is the fuel pump reset switch located?
on 1995 Pontiac Trans Sport

car was sitting up for a while, is backfiring and idles high

No fuel pump reset! Check for a vacuum leak.
When set up for a couple of days,starts fine. Idle increases(between 1500-2000rpms). I turn engine off, then it wont restart.I changed numerous sensors: mass air flow sensor, idle position sensor, fuel pressure regulator, idle air position sensor. It does smell of gas but engine will not start (smells something like when it would be flooded).
Check engine light on?