Unfortunately my 92 TR 4cyl EFI is still acting up as discovered on a XC trip last week.

Basically, after driving for a while, 100km or so, especially when it is hot, it loses power and surges (but doesn't stall completely). The more I press the accelerator, the more it surges to the point of being undrivable.
Turn off the engine for one second, restart and everything is normal again, until it happens again 10 minutes later.

I'm guessing that must be some computer problem? ECU? Are there any other computers hidden anywhere that could cause this?

there are so many things it could be

do you have a repair manual with the diagnostic charts
and a DIY with an LED tester or multi meter

if it isnt the ecu it could be fuel /filter/injectors
could be the coil exciter or dissy pin in or module

does the engine check light come on at all

I just found the codes in the shop manual and will give that a try.

The check light comes on but only for 1-2 seconds on every start, i guess that is normal?

Yep that normal :) Check engine stays on for a second then turn off :)

Yep that normal :) Check engine stays on for a second then turn off :)

something new i learnt, didnt know that thought my car was just old :XD

Finally did the diagnostic check. Output is 10101010, which according to the shop manual is code 15, or "normal state". Dangit. I also have a low idle RPM problem, was thinking both issues could be due to a faulty ECU. Guess that would've been too easy.

I did also check the coil resistance of the injectors and bench tested them, all good. Car still doesn't want to run for longer than 1hr though. I'm stumped.