Starting issue when engine is warm

Ok here is the deal.. 93 Infiniti G20.. when I start her up when the engine is cool no problem... but after the engine has warmed up... and I go to start it the engine will hesitate and bog down the rpms then return back to normal and a few rare cases stalled altogether.. now I think it could be a coolant temp sensor but I could be wrong anybody have any idea's what it may be??