1993 LUMINA Z34 CRANK BUT NO START BE LOW 35 DEGREES FAHRENHEIT

They SAY they checked all that. But on a 15 year old car, there is not going to be a lot of effort. Let me guess..they wanted to show new or newer cars A cold battery does not put out as much as a warm . 35° is not all that cold to have much of an effect. But you don't say if it cranks and tries...that bit on information is critical for us to help you. The er can go from there

If your engine has a hard time turning over, one thing to check also, but it has nothing to do with you current problem, is the weight of the motor oil. You should be running 5W-30 to help stop some of the resistance when turning over the motor on cold mornings/days. The more amps it takes to turn over the motor lthe less goes to the electrical system which needs a set amount to fire off the ignition. Does you car turn over quickly and start right away if you jump start it? If that is so, the battery may be weak, Have the battery tested and the charging system checked for proper output also. Have you ever put any additives in the gas tank to dispel the condensation of water? It may be just enough to freeze the pickup lines or even fuel filters to not allow enough gas. Cold weather prep may be one of the most important items you can do in the late fall.