Will not start when outside temperatures are hot

Hi Ashley and thanks for using 2carpros.com. The problem you are having can be the result of many things. The interesting thing is that it only happens when it is hot outside. That leads me to question the coolant temperature sensor. This sensor is designed to tell the computer the temperature of the coolant so the proper air/fuel mixture can be delivered to the engine. If the sensor is telling the computer (for example) it is -40 degrees, the computer will respond by making the fuel mixture extremely rich (too much gas for the actual temperature). I would recommend the following to begin. First, you will need to get a scanner that can read real time data. With the scanner, view the temperature sensor information and it should tell you what it thinks the outside temperature is. If it is wrong, then the sensor will need replaced.

I have attached a picture of the sensor's location to help you find it. Additionally, here is a general video explaining how to use a scanner. When you look at the picture, the electronic coolant temperature (ECT) sensor is the one in question. The other one is for the gauge.

https://youtu.be/YV3TRZwer8k

I hope this helps. Honestly, I had a van dropped off at the shop doing the same thing about a month ago and this was the problem. No guarantee, but this is a good place to start.

Let me know if it helps.

Take care,
Joe