My engine is stalling why?

This sounds like a fuel pump or the crankshaft angle sensor has gone out. When you turn the key to the on position without cranking the engine over can you hear the fuel pump run in the tank for 5 seconds?

https://www.2carpros.com/articles/engine-stalls

and

https://www.2carpros.com/articles/car-cranks-but-wont-start

Please run down this guide and report back.

Glad you could get it fixed, that kind of problem can be tough. Please use 2CarPros anytime we are here to help.

Hello,

It sounds like the crankshaft angle sensor is going out or the PGM FI - Engine relay is overheated and shutting down. Let's start by running the codes to see what comes up.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Here is the location of the sensor and the relay below. Check out the diagrams (Below). Please let us know what you find. Cheers, Ken

Please do, we are interested to see what it is.

Is the relay not in the place the diagram states or? What is the problem with the information.? Looks the same on my end :)

If your heat gauge is at normal do not worry about the heat on/in radiator if it overheats that is another thing. But you may be complaint about overheat so have your coolant system pressure checked for an internal leak like a head gasket. When the fans kick on the fans may have broken the bracket where they are mounted so have that checked. Ethylene Glycol is what is supposed to go in radiator not Dexcool, Dexcool is orange Glycol is green if you can find it. One other thing as you say your car stalls when heater is turned on check battery terminal ends for cleanliness and have battery checked for condition including load test.

First never put gas in when engine is running ( if that is what you mean).

Otherwise it sounds like an EVAP malfunction, gas is getting into EVAP lines and flooding engine.
A scanner can test EVAP system.

Also have charging system tested at most autoparts stores for free.

This is most likely due to trans change, something was not connected or connected incorrectly.
I would take it back to them.

This is a locked up AC compressor here is a guide to help fix the problem

https://www.2carpros.com/articles/replace-air-conditioner-compressor

Please run down this guide and report back.

I would check the fuel pressure when it stalls. You can borrow a fuel pressure gauge AutoZone with a refundable deposit. Simply hook the gauge up to the valve on the fuel rail, turn the key on, and see what it reads. Then start the car and record that reading too. Let the car idle until it shuts off, and check it again. Here is a more specific guide on that: https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Your readings should be: With the key on, engine off - 38-44psi, with the engine idling - 31-37psi. When the engine turns off, the car should hold at least 21psi for five minutes. Any less than these numbers tells us that you got a dud of a fuel pump (rare, but it happens. I got one recently myself).

If it is not fuel related, then it is time to check sparks. You can buy a spark tester for about $15.00 at AutoZone. Hook it up to any cylinder, start the car and let it idle until it shuts off. Then have a helper turn the key and observe.

Here is the tester that I use: https://www.amazon.com/Lisle-20610-Inline-Spark-Tester/dp/B0002STSC6/ref=sr_1_3?ie=UTF8&qid=1501325755&sr=8-3&keywords=spark+tester

Finally, some specifics would be helpful here. Which engine do you have? And is your car an automatic transmission or manual?

Let us know what you find and we will go from there.

Okay. I would still go with the tests mentioned above. Let us know what you find and we will go from there.