92 Chevy Astro won't start

I have an 1992 chev astro. Won't start unless I follow this proceedure: Press gas pedal to the floor then let up then turn the key. If I try starting the normal way of just turning the key then the engine would turn over real fast then I let go of the key (still in the on position) the engine doesn't make noise but the check engine light is on. I then press the gas pedal to the floor let it up slowly then it starts right up and runs well the whole trip.

Doesn't make much sense-- is service engine lite on? have codes read if so-- may be a bad throttle position sensor- but that should affect driveability as well...

Doesn't make much sense-- is service engine lite on? have codes read if so-- may be a bad throttle position sensor- but that should affect driveability as well...



The car didn't start but the key was in the on position and the engine light came on. When I press the gas pedal first it always start and runs smooth.