ok i have a faze tach but its was running fine then i blew a head gasket and got it replaced and ever since then my tach has been jumping so i checked all my wiring and its fines nothing wrong with it besides i still cant get it to light up but i changed my ignitor in my distributor this morning and it was running fine for bout 10 min then it started jumping again so can someone tell why its jumping an how to fix it?? and manbey how to get my tach to light back up??

 

did u hook the grounds back up to the head. could cause the jumping

 

yea

 

so just the tach is jumping, not a surging idle??

Probably not the case but check the alternator plug to see if wiring is connected completely, then again your car would be dying if this was the case but my tach was jumping like crazy when my plug came loose.

also, you might want to make sure you bleeded the coolant properly, a bubble can cause the idle to fluctuate which would cause your tach to jump.

 

ok ill try but yea its just the tach the car idles fine

 

ok i checked my ground and everything and i still cant get it to stop jumping