ok guys i tried in the firced induction section and didnt get much help, hoing the good old ef guys could help. first i got a solid cel. opened up the ecu and found a transistor "q31" is all burned up. ok, so i plug it back in, code 10 iat sensor. iat sensor had the correct plug plugged in, resistance checked ok, all troubleshooting was ok. i did some research and found a thread that said q31 is for the purge selenoid, which i do not have hooked up and its ok to run your car with a burned up q31. btw its a 90 si, b16a t3/t4, converted to obd1. chipped p72. also, i plugged in my pm6 ecu and no cel. so i must have recieved a bad ecu. should i replace that resistor? leave it? some one even posted to just break it off and leave it. hmmmm......

cliff notes: burnt up q31 transitor, iat checks out okay. plugged in different ecu, no codes. should i replace the transistor? leave it? new ecu? tia

 

I think it burns up when you switch the iat and purge solenoid, but I'm not sure, so mehbe you backwards the plug?

 

i already checked that out, red and green wires are going to the iat. iat resistance is 4, so the sensor is good. 5 volts from power to ground, 5 volts across the plug. troubleshooting giude says its the ecu. duh!q31 is burned. im hoping that i recieved the ecu like that cuz i know for a fact that they were hooked up correctly. i dont even have the purge selenoid hooked up. also i hooked up my old ecu, pm6 without the conv harness and no codes,

 

Sounds like the ecu then. Someone burnt it and didn't know or burnt it and forgot about it or something such.

 

lol i just went out and looked, the purge selenoid doesnt even have the same kind of plug. any who, now my question is should i leave it like that or should i try replacing the transistor? if q31 is only for the purge, then i guess i could leave it for now.

 

If it's not coding just leave it like so, but it's good to have. It's easy enough to replace, so I'd do it. Figure out what kind of transistor it is and I might have a spare.

 

i cant really tell what it says on it, its burned and cracked. now im throwing code 22, vtec. sweet.

 

Look at it on the good ecu.