my sister’s 1992 jeep will not start when the temperature falls below freezing.
More information please.
What exactly do you mean “will not start?” What exactly happens when the key is turned? Is there any sound? What sound? Does it click, does the starter move the engine, does it move it slower than normal, does it seem to try and start ???
How long has she had this trouble? When was the last time the plugs, wires, air and fuel filters been changed?
does not start at all, or has a hard time starting? or you need the magic touch on the gas pedal to coax it into starting?
more info please 
Villa12: For your convenience, I have bumped your original thread up so that you can see it.