Pulled this out of my 89, guess a previous owner put it in. I had no idea it was there.
Anyone know what it does? Only thing to identify it is the microchips really. Looks like there used to be a sticker on the guard covering the microchips but it's long gone now.
I don't know that unit specifically, but the early days of efi tuning involved using resistors inline with sensors like the temperature coolant and intake air temperature sensor, to artificially increase the timing. It of course affected fuel tables as well.
Basically, they made the ecu think the coolant and air temps were lower than they really were...
No reason to keep that thing on the car.