i have an '87 SC LG4 and whenever i start the car my tach jumps around wildly all the way from 600 rpms to 4000 rpms, but as soon as i start the car the tach reads 500-600 and becomes acting normal. Can anybody tell me whats going on?? Thanks for your help

 

Not sure... Your starting the car twice??? Or did I read it wrong?

 

No when i'm turning the ignition trying to start the car the gauge on the tach jumps around wildly and then once the car starts the gauge acts normal

 

Ive seen this on some cars before, either the tach is hosed or you have a bad ground somewhere... or possibly a short from the starter power lead.

 

its not hosed cause it returns to its normal condition after the engine starts, so i'm thinkin its a short, thanks for your help