SAFC II reports different rpm than gauge cluster! normal??

[whowutwut]

Hi, I found a post or two on this topic but none with any resolution.. maybe there is none :-D ... anyway.. So here goes..

I just installed a SAFC II into my car, it's a 1993 240sx hatch with a s13 sr20 blacktop with an E5 ecu, I'm pretty sure RPM wire is correctly connected, green from safc to the yellow/red wire in pin 3 of ECU, (I've double checked the diagrams over and over)

So what's happening is the SAFC is report RPM values lower than my gauge cluster. As I rev it up, the difference between the SAFC and the gauge cluster increases, this is what i'm worried.. The gauge cluster is a USDM stock gauge cluster.

gauge
cluster | safc II
value | reading
-------------------
1200 | 1000
2000 | 1700
3000 | 2600
3500 | 3000

Settings in the SAFC II are sensor 6 in 6 out, sens cal. 1 in 1 out, 4 cylinders selected, arrow pointing up to the right,

so my question is, is this normal? I've read about people who rpm values are off by 100 or so but consistently off by 100, this seems to increase...

Thanks for the help!

[nsn240]

I'd like to know the answer to this as well.. My first safc2 never had a problem. It somehow got fried and the replacement safc2 I got does the rpm thing...

Wiring is identical, just unplugged the dead one and put this one in. My friend had a similar problem then found he was on 6cyl...

[bardabe]

the easy way to find out wich is wrong is to unplug ure maf and try and rev over 2500 wichever one bounces off +/- 50rpms 2500 is correct.