Starts and dies

Need advice. 99 corolla. 245000 miles. Runs like a champ. (Or did) started it cold the other day and shut it off before it idled down. Now it starts right up but dies right away. Plugs and wires are fairly new. Cant afford to just throw parts at it. I was thinking fuel, but like I say, it does fire up. Cant get it to a code reader so I'm just looking for some quick ideas. Thanks in advance. Its getting cold out here.

Code readers are dirt cheap for a basic one. You can get one on Amazon for $15. Harbor Freight has one that is a little better than the super basic ones, but still nicely priced at $40.

One issue I ran into, on a Toyota no less, was the coolant temp sensor. I had actually forgotten to plug it back in upon reassembly after changing head gaskets and same thing. It would start, run for half a second and die. Once I put a code reader on it and saw the coolant sensor code I realized what I did, plugged it in and it fired right up.

If the coolant sensor isn't plugged in or fails the ECU thinks its -40* and just dumps fuel, so much fuel that it can't run. Another possible issue could be a cam or crank sensor. If there is a code reading that code could save you a ton of time rather than just guessing.

Thanks. Actually just switched out the temp sensor last summer. Will check it. Thanks again.

Just to be clear there are usually two temp sensors. There is one that the ECU uses and one for the gauge. The one for the gauge is usually just a single wire plug, and the one for the ECU is usually a 2 to 3 wire plug.