cold start/ Idle idduse HELP!!

[Hksuperman4000]

I guess I have hat common people cold cold start, but whats weird about mines is that I have cold starts even after the car has been warmed up. I start it as usal and the idle will drop down to zero and die out. This isnt just for the morning ubt usllay anytime I turn off my car and turn it back on. Say I run to the cornerstore for 1 minute and turn the car back on it will have "cold start" I would need to rev it a few time to 4000 RMp before it idles normally. What weird is that at times it would idle around 200-300 rpm is feel as if its going to die out but usllay dont. I dont know whats wrong dont even know where to start any help would be nice thank. I drive a 1993 240sx coupe thank you

[gremlin]

I guess I have hat common people cold cold start, but whats weird about mines is that I have cold starts even after the car has been warmed up. I start it as usal and the idle will drop down to zero and die out. This isnt just for the morning ubt usllay anytime I turn off my car and turn it back on. Say I run to the cornerstore for 1 minute and turn the car back on it will have "cold start" I would need to rev it a few time to 4000 RMp before it idles normally. What weird is that at times it would idle around 200-300 rpm is feel as if its going to die out but usllay dont. I dont know whats wrong dont even know where to start any help would be nice thank. I drive a 1993 240sx coupe thank you maybe your fuel pump is going out. It would be good to test your fuel pressure anyway. Also the fuel pressure regulator. check the coolant temp sensor also.

[cosil8e]

this was happening to me as well. my ground wire on my alternator was in poor shape so i replaced it and it seemed to fix the problem. i assumed that i was getting poor spark because of the poor ground. and yes i was also fouling spark plugs.