installed bad ECU and now no TPS or Baro..

[xchief1320]

I swapped in a ECU from another car to verify if it was bad or not and when i tried to start my car the ECU started smoking.i pulled it out and swapped back in my ECU and the car started right up.But when i went to drive home the check engine light came on.I looked at the logger and it showed the TPS 3% at idle and would only go to 7% at WOT.Also the Baro was at 7 instead of 98 or so like it normally is.

I swapped in another TPS sensor and it's doing the same thing.I am not getting 5V at the sensor so i added a 5V wire to see if that fixed it,which it did not.

I am lost at this point. What could of went bad that took out my 5V reference to the TPS and the Baro? the IAT works fine,as does the rest of the sensors..And the car runs good except when i get into boost,then it falls flat on it's face..

I added a 10K potentiometer for the baro and got it working again.But i had to add a 5V reference wire to the potentiometer to get it to work.I just have to fix the TPS somehow..

Thanks for any help you may provide..

The car is a 91 Talon TSI AWD 5 speed..

Steve

 

[xchief1320]

also another thing i noticed tonight.The A/C doesn't seem to blow cold anymore.I don't think the compressor is kicking on..I know that sounds weird and it might have nothing to do with the sensor problem and just be a coincidence..

Just figured i would throw it out there just incase it does matter..

I need to figure this thing out,it was actually running perfect till all this.

Steve

 

[xchief1320]

Fixed the problem. the factory 5V reference wire "pin 23" was slightly shorted out causing high resistance in the wire.When i added the seperate test 5V reference wire i didn't cut the factory one out of the loop so it was dropping the voltage down to 1.2 volts instead of 5V.I cut the wire at the TPS sensor and at the ECU and added a new wire to test it and now it has a full 5V at the tps sensor.

As for the Baro I hooked it up on a 10K potentiometer so i can adjust it to wherever i like.i keep it around 98-99 though."sea level"
I could hook it back up like it was factory if i wanted too.but i like it like it is now..

Steve