Okay I am having problems with my car 1991 HB.. I have a b16a swap.. First off I am not throwing codes. My car wont start after work.. The reason i say this is because when I leave it overnight it starts right up the next morning, but after work it don't.. Is it because of the temperature. Its usually cooler at night and my car starts right up. When I mean it don't start the motor turns. But it seems like its not getting gas. I tested to see if I was getting spark and I am. I changed my Temp. sensor. Checked all fluids, vacuum lines, sensor connections, and battery connection. The funny thing is I have no smoke of any kind coming out my exhaust. But when I get it started it runs fine. 100% fine it doesn't sputter or jerk. It idles at 400rpm. But when it starts from a cold start there is a delay on throttle response. but when it warms up. response is normal. But its just when I leave it during the day for 8hrs. but at night for 10--9hrs???????? Its seems when its warm that's when I start my car up no problem one turn of the key and its on....This started couple of months ago. and is gradually taking up to 8-7 turns of the key. the day before I couldn't get it started till few hours later...My swap was done In Feb of this year. and started with no codes or problems till now... Could the O2 sensor be the cause? Could it be the fuel pump? What other sensor would cause this? Is it even a sensor? Help..