Hello, after 4 years of my car running flawlessly it suddenly developed problem where engine shuts off when hot and won't start again until it has cooled off.

I was wondering if it could be a bad cam sensor but composite log looks like this:


I'm not sure how composite log works but that takes a while to appear when cranking.
Also attached composite log .csv file and megasquirt datalog.

Also after while of cranking my afr gauge shows something like +22, not sure if that is relevant or not. Also there is no gas smell but not sure if there should be after multiple tries of cranking without car starting.

Relevant car specs:
1999 1.8 NB with 90k miles
MS3 Enhanced by MSLabs
Toyota COPs
Stock fuel pump

 

This happened to me on my 2000 NB several years ago... Engine died and I coasted to the side of the road. Engine would not start. Brought the car home on a tow truck and it started right up. The camshaft and crankshaft sensors on the 1999 - 2000 NB's are known to fail with high temperatures - Texas summer 100+F. I did not know which sensor was the problem so I replaced both. Fixed...

 

Probably a cam sensor, I always carry a spare of each and have never used one on the road, track car was different, did a couple with it but there was a lot more heat in there. Cam sensor is easy to change (and the less reliable of the two), do it first, or just do both on the basis that whichever is working well is going to fail soon anyway.

 

Yeah I was thinking about the cam/crank sensor but if I read that composite log correctly, they seem to be working fine?

 

Based on your composite log, the problem seems to be from the crank sensor.