When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I installed a Factory tach. in my 86 F150 302EFI. It's been working fine, but it seems my tach. ain't given the correct RPM's. Is there a way to calibrate the factory tach. or a step a missed while installing it?
It shows I'm running lil over 3K @65-70MPH in 4th. It don't add up right since I have a non-granny 4spd, 3.00:1 9" wearing 31-10.50-15 tires. The tach. a few days ago seemed to be reading right. it dropped down near 2K for awhile, then went back to running high RPM's.