TACHOMETER DOES NOT READ PROPERLY
If the tachometer operates but reads incorrectly:
Check for proper cylinder selection:
Gas vehicle cylinder selection
#1 4 cylinder also used on GM LS engines (use 10K-ohm pull up resistor per booklet one side to signal, one side to 12V power)
#2 6 cylinder
#3 8 cylinder
If the signal pulse count or output is unknown, then you will have to experiment for the best result.
Once the proper cylinder selection is found and selected, there are some fine tuning potentiometers on the back of the tachs. They can be accessed by poking through the stickers on the lower portion of the tachometer.
Using a #00 Phillips head bit, the tachometer can be adjusted. On sime models a small allen head is used, you can also use a small star bit.
Tachometers with one adjustment screw:
The screw is to adjust the range, generally within 500-1000
Tachometers with 2 adjustment screws:
One is to adjust the range, generally within 500-1000
One is to adjust the zero position
If the tachometer still reads incorrectly please contact NVU tech team at 248-850-5482 and have the following code ready:
ACT1450