rb20 tach question

[mikalkouki]

I have a 5 spd rb20 in a 95 s14 (originally an auto). I'm trying to adjust the pot on the back of the tach to get it to read properly and no matter how I adjust it the tach just bounces around under 1k. I also have a SAFC hooked up to the same tach wire and it reads properly. Does this mean my tach is trash? Or does anyone have any suggestions for something I may be doing improperly?

[mikalkouki]

bump

[Sil240]

The pot????

Your Tach will not read properly at all unless you have a resistor inline or you have a 6cyl tach or send it to LS auto.

Assuming you have the stock tach, it is calibrated to read a 4cyl signal, but it is reading an extra 2 pulses per revolution.So it will read higher than it actually is.

If your tach is waivering then there's probably something wrong with the wiring or maybe your car is not idling correctly.

I would go by the SAFC if its reading the tach signal straight from the ECU.

I just bought a aftermarket tach.

[mikalkouki]

I read a post where wulfgang stated that the s14 tach will work properly with the rb20 if you just calibrate the potentiometer ("pot") on the back of the tach. Is that false?

[Sil240]

By modifing the Potentiometer i believe he ment using a resistor.

Guys were doing something to make it read CLOSER, not accurate but closer. But it was still OFF.

Think about it's reading 1.5 times more pulses.

[mikalkouki]

nah... I'm pretty sure that he clearly states there is no pull up resistor needed.... check out this post! zerothread?id=81824