View Full Version : 325is technical question....

12-18-2001, 06:28 PM
What is the function of the sensor on the #1 spark plug wire on a 87-91 325i? I ask this question because I just realized that I raced the entire 2001 season without one. It wasn't there when I purchased the car, so I didn't know it was supposed to be there until I bought new spark plug wires and the new set had one. My guess is that it has to do with timing advance.
I'm real curious if I will see a performance change with one.

12-18-2001, 08:47 PM
what is the month/yr build of your car? up to late 87, that wire was not there. it is an inductive pick up used to sequence the fuel injectors. early model fi systems did not use this. if you have an '87, it sounds like you may have bought the wrong wires.

two '88's, with the wire.

12-18-2001, 11:16 PM
It is a late 87.(october) There is a place for the sensor to plug into the wiring harness underneath the intake manifold right behind the alternator. My guess is that the previous owner purchased new wires, and got the wrong ones.