Where to pickup tach signal for rpm datalogging on 2000 XJ

[nicpaige]

For anyone that has hooked up or needed a tach signal for aftermarket tach or data logging rpm where did you tap into and are any accessories needed for a square wave signal?

[jsawduste]

Good question, on the coil pack engines Jensen has told us to take the signal from the ECM. Pin 33 IIRC.

But it didn't seem to give an a accurate reading using
Autometers.

Not an answer to your question but an observation.

[SilverXJ]

On my Apexi AFC, when I was running it, I used pin #18 on C1, TN/YL, the black plug on the pcm. This is the cam sensor signal. If the gauge has # of cylinders setting you may need to play around with it. On the Apexi it was set to 1 cylinder.

The CPS might work as well, C1 #8. I believe this is where the AEM FIC gets the RPM from, but it does have a calibrate feature.

[nicpaige]

Thanks!

[nicpaige]

Any thoughts or comments on the Zeitronix ZT-2 logging setup?

[SilverXJ]

I haven't personally used it, but I have heard a bunch good of it. Plus I like that data display and all the points it logs.

[gradon]

Cam sensor signal is what you want.