staying started

I have a 1995 mustang and after i drive it turn it off and a couple of minutes later i start it it wont stay started unless i hold the gas peddal down where the RPM's are at about 1000 so I drive two footed for a while and I could let it go and it will stay on but it's fine if i let it sit for a while before restarting it. this has ben happening ever since I hotroded the hell out of it trying to get it from being stuck in the snow. I was told to take off and spray carb cleaner on the idler. what all could be causing the problem? I would appriciate if somebody has the sollution to this. when I said idler i ment the throttle.