V5/6 STI Intake Air Temp Sensor

[samlogan87]

Hey everyone,

I have put a V6 sti motor into my legacy with the factory j2 ecu that came with the engine. I am having a few issues regarding the intake air temp sensor. I have a feeling i might have wired it in wrong and it is giving me an intake air temp of 205degrees which i know is not right. I was wondering if someone has one of these cars and a multimeter would they be able to check to see if one of the two wires has a direct 5 volt feed because currently i have one wire connected to the ecu and the other to earth. i have had a look at earlier model subarus with the same sensor and they seem to be connected to a 5v feed and then go to the ecu. If someone wouldn\'t mind checking that for me that would be awesome. Unless someone knows for sure that is the case. There is very little info about them floating around. Also the car the engine came out of had a factory auto water sprayer for the intercooler. does anyone know what ecu pin it is?

Cheers

Sam

[hijacka]

Try using the earth from the ecu.

[samlogan87]

That\'s the earth I used. It\'s connected to sensor earth atm

[gotasuby]

Does the factory ecu have pull up or not? If it doesn\'t then connect other to 5v

[samlogan87]

i managed to figure it out. I had a bit of a wiring fault when i first installed the engine and ecu into the car and blew up the resistor for the 5v sensor line. So i bought another ecu that had been tuned by exit co in Japan. It was not an sti computer but i was not worried as it had more fueling added to it. I have now figured out how they did it. They must have internally changed something so that the ecu thinks that it is 200 degrees outside which in turn will get it to add more fuel. Sneaky way of doing it but it did mean it ran like crap as it was flooding it all the time and the exhaust stunk of fuel. I figured this out as i had the old ecu repaired and it is reading the proper intake air temp. Plug the modified one back in and it reads 200 degrees. I added 5v direct to the sensor pin on the ecu and it still stayed at 200 just in case the wiring was different between the two as i have found wiring diagrams from that era (P1 model) with external intake air temp sensors and they get a 5 volt feed from the sensor 5V line and must earth through the ecu.

Sam