I have been considering doing the AC delete on my 91 TBI bird for several months now but can't seem to find the answer to one question. I understand the need for the AC delete pulley and heater box so that would be part of the project. I also know the AC communicates with the ECM, I have read in my helms manual that the data from the AC to the ECM is either on or off. I have not been able to find out, however, how this effects the rest of the ECM//emmisions system. I live in Milwaukee where we have somewhat strict emmissions testing, and I don't want to remove the AC if it will cause problems. If anyone knows what the AC sensor effects, or if there is an effective solution (plugging in a resistor in place of the AC or something). Id really appreciate the help.

 

thats just for the 2nd fan if equipped. when it comes on, the ecu will turn on the 2nd fan. or if its a single fan and it aint on yet it will turn it on.

 

You don't have to do anything about that. As far as I know, the ECM only needs to know when the AC is on just so it can compensate for the drag when the AC compressor kicks on (so it can bump up the idle speed), but there may be more to it than that. Just for comparison, I deleted the AC on my car around a year ago and noticed no ill effects, no increase or decrease in gas mileage, just a lot more room in the engine compartment.


EDIT:kyle88bird is right, I forgot about that. If the car has dual fans, turning on the AC will turn on the second fan. But, I don't think any of the TBI cars came with dual fans.

 

Same here. My LO3 auto just got a lot cleaner and I got rid of a parasitic accessory, you shouldn't have any problems with emissions or the ECU.

I haven't.