so my 1999 v6 mustang won’t idle good after it’s been sitting maybe 30 mins and on a warm start say if i drive 20 minutes go in a store for a few then start it back up it’s idle very rough until i get the car going down the road. i have no idea what the problem is it only does it when the engine is warm but it’s fine when it’s a cold start. thanks.
Odds are your fuel injectors are not delivering the correct amount of fuel (leaking/dirty).
A cold engine requires more fuel on startup hence the car starts fine when it’s cold. A warm engine doesn’t require as much fuel and that’s probably why it’s running rough.
no it’s fine off cold starts i have no idea what it is
If it’s not the injectors, check the coolant temperature sensor - https://youtu.be/MvBHUUMezRY
If you can’t diagnose it yourself, take it to a professional mechanic & have them diagnose the problem first, before you start throwing parts at it.