93 coupe cold start problems

[C Green]

I have a 93 coupe that refuses to start if its cold outside like below 40 degrees. It turns over fine and kinda makes a sucking sound. If you try it when its warm it cranks first try. Mostly stock except for exhaust. Ive replaced sensors checked Idle air bypass. Fuel pump does run all the time. I dont know why... I guess someone has rigged it. anyone know how to fix my cold starting problems Ive given up.