10-17-2012, 10:18 PM
Join Date: Nov 2010
Location: Originally from Germany. Now live in SoCal
Total Cats: -6
92 1.6l MS2 Tach Input Problems
Hey guys, I have a ms2 pcb3.0 I'm trying to run on a 92 1.6 miata.
It was running ms1 pcb3.0 (tach-in through hall circuit, msextra.com miata ms2) perfectly fine, but it would not receive tach-in after the ms2 upgrade. We sold the unit and attempted to try again, but I still can't get a clean tach signal to ms2 from the car, which is odd because I was able to with ms1. I decided to install the VR conditioner circuit because I believe it is a better tach input circuit, which I have also read online.
I now have CKP installed like this:
CKP to db37 pin 24
TACHSELECT to VRIN
VRIN to 1k Ohm to 5v Proto
VROUT to TSEL
and CMP installed like this:
CMP to IAC1A
IAC1A to js10
js10 to 470 ohm res
470 ohm res to 5v proto
I've tried TSEL to VROUT and VROUTINV, and I've also tried input capture to rising and falling and every combination i could think of, no change in anything. Just a tach signal that will show up for a few rotations and then disappear. VR pots are adjusted full ccw, and the bottom one turned 6 turns cw.
Using the VR tach input circuit, what jumpers/pullups does the ms2 require for the CKP signal to get to the processor? Does what I have look right to you guys? My hair is falling out.
The attachments were made using a JimStim 1.3.