my afc is reading the wrong rpm

[2fast4y0u]

so i have been getting my car ready lately (just in time for snow :( )

anyway, the last few weeks everything has been fine. this week my afc started raeding different rpm then my tach and my g.u.s. gauge. the tach the g.u.s. gauge are perfectly in sync but the afc starts 600rpm off and can be 900 rpm off at cruising speed.
i cant tune my afc for the correction i need at certain rpm because its off...WHAT GIVES???

i checked the connection(which hasnt changed in 3 years) since the install and everything is great. i soldered them together and taped them up.

any ideas??

[keytops]

Did you somehow switch it from the 4 cylinder to the 6 or 8 cylinder setting (if it has an adjustment)?

[2fast4y0u]

That would be the issue...i reset the thing the toher day and didnt put it back on 4 cylinder.

Thanks!