Cold Start
 

I have 90 300zx TT. I have to push the gas in order to start whether it is cold or not. When it cold, I have to warm it up around 5-10 minutes by press the gas over 2000 rpm, it run fine after that. If I do not continue to, the engine will come to stall. Any one have any suggestion? I already replace, spark plug, MAF but still have the same problem. Thanks,