This is a discussion on 2002 wrx does not start when warm within the General Maintenance, Troubleshooting & Accidents. forums, part of the Tech & Modifying & General Repairs category; On a tangentially related side note, my younger brother used to have a nitromethane powered rc car that would start ...
On a tangentially related side note, my younger brother used to have a nitromethane powered rc car that would start when cold, but would not start again when hot after stalling. Our best diagnosis was that the piston sleeve was not sealing well to the piston. When the engine was cold there was just enough compression to start, but after warming, due to differences in thermal expansion, there was not enough compression to run.
I wonder if your compression and leakdown change with temperature.
David - '05 WRX, stock except uppipe and rear swaybar
Have you logged the car? Is your O2 sensor working properly? If you're getting that bad fuel economy I want to know what your AFR looks like.. when you changed the plugs were they black (did all four look the same--can you post pictures)? Do you have excessive suit on your tail pipe?
Dumping too much fuel will cause it to not start when warm because it will flood the engine. You might have a failing injector that is sticking open.. or even a failing FPR. I think we're getting somewhere now..
Heated front o2 sensor?
I am having the almost identical problem and i have heard several things to try but im interested to know if you were able to fix it and what "it" was causing the issue if you could message me that would be great