88 prelude 2.0 si wont start when its cold

All has been well with car, always started after 1 or 2 cranks. Check engine light went on the other day and now it does not want to start when its cold. Is there some sort of sensor that acts like a choke. It seems like it is not sensing that it is cold out or something like that. I can get it started but it takes forever. The check engine light stays on when I do get it started. When its warm it will start with no problem. I'm sure it must be a sensor just don't know which one or where it is located. I also have a spare 1990 2.0 si to scab parts from so if someone could lead me in the right directions I can start to change out parts. Thanks in advance for all your help.

If you can still hear the engine cranking (weakly), and all the electronics are still working properly (the battery is still good), then I would guess that the gasoline in one of your fuel lines or fuel injectors is frozen.

Typically this does not happen, but when water gets in there it can easily freeze in these kinds of conditions. Buy a bottle of one of those fuel antifreeze things for this kind of stuff at Walmart or Autozone.

The other day the temperature dropped to -32 degrees (that's without wind chill) here and my Prelude took quite a few cranks to get the fuel moving again. The next night it was (barely) a bit warmer at -28 but I poured in a bottle of Heet and it pretty much started right up the next day.