bad@ss89camaro

how do i fix my rpm guage in my 91 z28 convetible automaticc its way to high when im doing about 70 its kicking at about 7500 and at idle if i verily rev it up it jumps way up to topped out im doing a complete tuneup this weekend and want to fix that while im at it so i can set IAC or whatever its called and set my timing

Quick_Trans_Am

iTrader: (2)

sounds like the tachometer itself is on its way out. inspect the signal wire at the distributor first to make sure it's connected and there are no shorts in it. Hope that helps you some

dj haf

im having the same problem. idle looks like it's at 1500 rpms, and when im at WOT, it goes past 7 into the black, THEN shifts. i had people tell me i need to get a new tach, so i'll do that when i get my MSD 6AL... if there's anyway of fixing without getting a new tach, i'll do it... but as of now, getting a new tach is all i've been told to do that would fix the problem

DJsyclone

in my 89 RS 2.8 auto the tach always seems to be reading faster than I think it should, at 70mph the needle sits at 3500. is that the norm? other overdrive cars I've driven cruise around 2000rpm.

bad@ss89camaro

i believe thats about right for a 2.8 liter

i have another 91 guage cluster well its a 92 but should fit ill change rpm guage out or ill change whole close after i check wires thanks guys

Dragons91RS

this is a common problem with 3rd gens. the stock tach's are total crap and go out. mine is real bad. at 60mph my stock tach shows 4000 RPM(has been getting worse recently) my actual engine rpm at 60mph is 1600.
sadly there is nothing you can do other than install an aftermarket tach.

dj haf

my friends always take a dump when i hit it in the car, they're like "omg your going to blow your engine! stop stop!" cuz the damn tach goes past 7 grand and keeps going... it's kinda funny to see them get all nervous and then calm down when i tell them my tach is fubar

Quick_Trans_Am

iTrader: (2)

Pretty funny. I've talked to GM before about the gauge cluster (at least the one for the firebird) and they've told me it's a "non replaceable unit" meaning I have to send the WHOLE cluster in to get it serviced, instead of replacing the tach alone or the oil pressure gauge, temp gauge, etc. individually. This is BS. I went to a junkyard and bought a dash cluster and replaced the faulty unit, haven't had a problem since.

bad@ss89camaro

thanks 4 the help guys i figured it out it was the gauge i had an extra guage cluster from a 92 so i put it in and it looks better any way becuase the needles of the 92 are orange and my 91 neddles were yellow i like the yellow better