something getting hot ?
 

I have an 87 supra turbo automatic runs perfect for 15 miles then goes to the limp mode,something is getting hot and making it not work right. I am runnig 3 codes 24,31,34 doesnt seem to effect performance for 1st 15 miles or minutes lol which ever comes 1st. I replaced the map sensor new wastegate and did a boost test nothing changed. I am baffled at what causing the problem. is it the computer? wiring ? or something else? please help as there r no mechanics that can tell me anything except throw more parts at it.

So is your car overheating? Or are you just guessing that it's a heat related issue? Try testing your AFM and double check your intercooler pipings to see if they're still good and no leaks. Maybe it can be your ECU, but I would see that to be your last resort

no car is not overheating,temp guage anyway stays in the normal range what i was getting at is i think my wiring or my ecu is getting hot and shutting me down or something else very little i havent replaced my wiring at cam position sensor rewired about 6 inches. Is there anything else that could be the problem? if it is my wiring that is bad like the cps can i not rewire just the critical wires afew feet and be ok would buy a complete harness but they want about 1200 bucks for that might as well buy another supra lol.read the article about the guy that had leaky capacitors and fix them and cleared all his problems wish that was the case here 238 dollars to have it checked. I cant this car to anymore mechanics all they do is charge and wont let u into their shop come back in a few hrs or next day they havent done anything but suggest u buy a new wiring harness for 3000 bucks or hey will do new piping on your car for 1800 turns out most these guys dont even have an ob1 code reader. U guys no more about these cars than toyota mechanics i have used. checked my piping with a boost tester didnt see anything bad did replace the plastic elbow that goes into the right fender but codes remained the same. please give me ur best thoughts. thanks

Your 3 trouble codes all seem to be pointing to the AFM or its wiring. You can check the wiring by measuring the resistance (or continuity) of each wire from the AFM connector to the ECU connector. If you have little to none resistance then the wiring is most likely okay. Also you should test your AFM as suggested earlier, or at least swap out with a known good one if that's an option.

Make sure its not a problem of going from closed loop (cold) to open loop (warm). That is when the oxygen sensor provides signals to the ECU. The test procedure is outlined in a good repair manual or online at sygnus x1. You will need a ohm meter. Check the oxygen sensor for a open heater circuit. You can also check the throttle position sensor. Sometimes they stick and don't come back to idle even though the throttle plate has. You will need a ohmmeter an a set of feeler gauges and a offset (s shaped) Phillips screwdriver. Work with a paper towel under the TPS to catch a screw if dropped.


http://www.cygnusx1.net/Supra/Library/TSRM/MK3/