03 Tiburon Gt won't idle unless gas pedal pressed
 

When I start it up it dies right away won't idle at all. When gas pedal is pressed down it will pop a little but when you let off the gas it dies instantly. Has anyone had this problem before and how do you fix it? Thank you for all your help.

Any codes?

without a code or check engine light on i would guess it is the TPS since hard starting and idle problems are normally this. when you open the butterfly it is in closed loop limp home mode and runs at reduced power. the IAC could also be a problem but not normally with starting and idle unless under high load conditions like A/C on and high electrical load. the MAP/IA sensor can also contribute but normally will not keep it from idling. again the limp home mode comes into play if it is faulty.

you need to use a OBDII scan tool and pull trouble codes. or get out that trusty old volt/OHM meter and do some break out tests on engine control sensors i would start with the TPS. i say this because an intermittent "soft code" will store but not turn on the check engine light. the TPS does trip this type of code a lot. only "hard" codes turn on the check engine light. a soft code will cause it to flash then go out. that is easy to miss.

the other problem is a hella big vacuum leak at the manifold. this may or may not trip a soft and or hard code.

time to do some trouble shooting my friend have fun! :D