Okay so heres the issue.

My tach is going nuts. Its a 91 hatch, stock tach. Its jumping around like crazy. It idles fine, but past 2500rpm, it suddenly starts going nuts. At first I thought it was a loose cable, but its going up AND down, not just down like its disconecting. Then I thought it was the ignitor, swapped that, still doing it. Somtimes it calms down and behaves, but it still seems to have a little jump around 4000rpm. The weird thig is its just that tach, its not like the car is acually changing RPMS! Now before I go and spend the money on a new dizzy, anyone here have any ideas of what it would be? Thanks guys.

Oh yeah, and its not the cap and rotor I dont think, and yes......I did a search.

Thanks for any help anyone can give. I really dont wanna have to spend the money if I dont have to.

 

maybe the contacts for the tach signal are dirty

the tach output wire is the blue wire coming from the dizzy Black/Yellow and Blue Plug

The blue wire runs to the Big Square plug on the Passengerside Tower unplug that and clean out the old anti corrosive grease and apply some new dielectrical grease make sure you plug it in all the way

see if that helps

 

yeah when i had my crx it did that too! it was like everytime i was bumping trance music, the needle would jump to it! lahahahahahah....nah seriuosly, its dirty like the dude above me said, clean that ****, throw in some fuel injector cleaner too, not into ur dizzy, but into ur tank, should be fine then, good luck

 

Thanks for the replys guys,but I gave it a try and its still jumping. Am I screwed? New dizzy time? Anyone else got any ideas?

 

i got the same problem... i already replaced the dizzy with one that was working on my friends car and everytime i get past 5k rpm it starts jumping... i dont know what to do either..

 

Try swapping out the "ignitor" for a good one. It's located inside the distributor. Faulty ignitors cause the problem you are all talking about.