Eric L. M.

for the past week or so i've noticed that my tach likes to do stupid things. for example when my car has sat over night and i first turn the key to "run" without starting the car, i notice that the tach jumps to 900 rpm for some reason. but while i turn the key to start and the engine turns, the tach climbs up to 4000 rpm and stays there with the engine running. the engine isnt turning that fast at all so i know something is wrong with the tach. the tach decides it wants to work like it supposed to after a couple of minutes and it only does this after the car has sat over night. i have no idea what the heck is going on or how to fix it except cleaning the contacts for the tach. anyone got any ideas? and in case anyone was woundering its the original tach that came in the car from ford. sorry this was so long.
thanxs in advance for any help..............E

Eric L. M.

forgot to mention its a 92 gt, 5spd, with 159,000 miles, and mostly stock.

kstinson

Mine does like that. WHen I shut it off it goes to 0 but with the engine running it is stuck at 3500. When I get on the gas it will eventually start moving. However it is never right. I figured out RPM using vehicle speed, tire size, and gears and the tach is always about 1500-2500rpm high. Any suggestions on this one would be nice.