I installed my FJO wideband last week. Since then I have been struggling to get the tach reading correct. I currently have the /12 factor in and it still reads 1600 rpm at idle. Stock tach reads 750(correct number) I am picking up the tach signal from the wire behind the stock tach. Engine is B16, ECU same, engine management is stock, the only diff is I have the MSD external coil. Any ideas or people with similar problem?

Thanks for the help

 

bump for a little help

 

Is there a better place to post this?

 

Just in case someone else has this same problem.
I got it working last night.

To start I originally tried 3 different locations to pick up the tach feed:
1. I spliced the wire behind the stock tach.
2. Connected to the negative side of the coil (external coil)
3. Picked up the blue wire inside the dizzy.

All of these locations gave erratic readings on the datalog PC.

I talked with tech at FJO and the recommended putting resistors between the tach pick up point and the FJO unit to filter out noise and give a clean signal.
I did that, but there was no improvement to the tach reading.

I was really confused because my stock tach was reading correctly all along.

Finally I decided to pick up the signal at the ECU.
I spliced into the white wire (B15 I think)
I figured that would be the cleanest signal in the car.
Sure enough that did the trick.
PC tach is smooth and accurate.