what would cause stock tach to be off??

[96darkhorse]

what would cause the stock tach to be off?? ive been having this prob. for a while

 

[94TURBO5 O]

It's stock that's why. If you hook up a monster tach you will see about 500 rpm diffference, at least I did.
How much is yours off?

 

[maypo59]

^^^what he said^^^

 

[1105]

^^^what they both said^^^

When I hooked up the timing let to my car and checked the RPM with it, my car was reading 900 and the light was reading 650.

 

[96darkhorse]

its close to 1000rpm off...when i had my car dynoed, they told me that when my tach was getting to 6000rpm their comp was around 4800!!! maybe they exaggerated

 

[95snoozer]

cause it was made by ford





if you want to know the important RPM, get a minishift light. it can be had for cheap and you can mount it wherever.... even behind the a/c vent