1991 Camaro RS - Tach Pegged Out when running

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Feb 20, 2008 | 11:01 AM

scarello

Thread Starter

Junior Member

Joined: May 2007

Posts: 46

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Car: 1991 Camaro RS Convertible

Engine: 305ci

Transmission: 4-Speed Auto

Axle/Gears: 2.73

1991 Camaro RS - Tach Pegged Out when running

Any reason why when the car is off the Tach sits at "0" but when running, it pegs right out, even though the car is idling fine?

Bad Tach?

1991 Camaro RS

Steve C - RI

Feb 20, 2008 | 11:20 AM

IROCWPB

Member

Joined: Aug 2006

Posts: 160

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From: West Palm Beach, FL

Car: 88' Camaro IROC-Z

Engine: 383ci TPI

Transmission: 700R4

Axle/Gears: stock

Re: 1991 Camaro RS - Tach Pegged Out when running

Yeah, one of the resistors in it went bad.

Feb 21, 2008 | 06:05 PM

1991ON20's

Member

Joined: May 2006

Posts: 172

Likes: 0

From: west jordan,UtT

Car: 91 RS, t-topped, man trans.

Engine: 350cid 350Hp crate motor

Transmission: t5 with new stock clutch and parts

Axle/Gears: 3.08 stock -RS

Re: 1991 Camaro RS - Tach Pegged Out when running

same here.

Feb 22, 2008 | 01:56 PM

BigBadLou

Supreme Member

iTrader: (3)

Joined: Jul 2004

Posts: 2,989

Likes: 9

Car: '91 Z28 convertible

Engine: TPI

Transmission: T5

Axle/Gears: 3.27 posi disc

Re: 1991 Camaro RS - Tach Pegged Out when running

If it's always pegged out with the key on, it could be a bad driver circuit. Those are not used anymore so they are hard to find but it's still repairable. I can look if I can find one online.

Lou

Mar 11, 2008 | 12:22 PM

scarello

Thread Starter

Junior Member

Joined: May 2007

Posts: 46

Likes: 0

Car: 1991 Camaro RS Convertible

Engine: 305ci

Transmission: 4-Speed Auto

Axle/Gears: 2.73

Re: 1991 Camaro RS - Tach Pegged Out when running

Ok.... here it is

The Tach is pegged when the car is off or when you first turn the ignition on.

When you go to turn the car over, the tach returns to zero RPMs, but as soon as it starts, it pegs right out again.

Bad tach?

Steve C - RI

Apr 8, 2008 | 10:10 PM

micktroup

Member

Joined: May 2005

Posts: 239

Likes: 1

From: California

Car: 1991 Z28 Camaro

Engine: 5.7L V8

Transmission: auto

Re: 1991 Camaro RS - Tach Pegged Out when running

I just bought a cluster off ebay and my tach does the same thing!! I bought it because my temp gauge was off and being an automatic, I don't really need the tach, but I would like to to work correctly.
Any help with fixing it would be appreciated- I still have the old cluster for spares if needed...

Apr 9, 2008 | 01:05 PM

micktroup

Member

Joined: May 2005

Posts: 239

Likes: 1

From: California

Car: 1991 Z28 Camaro

Engine: 5.7L V8

Transmission: auto

Re: 1991 Camaro RS - Tach Pegged Out when running

Update: Since the tach worked on my old cluster, I simply pulled the tach circuit board from it and swapped it into the replacement cluster. Works perfectly! 21 minutes to access the cluster, swap boards and button it all up!

Suggestion: anyone that has torn down a 3rd gen and had a working tach, pull the board and make it available on the site- obviously you will have a buyer or 2, given that the dealer wanted to sell me a new cluster for $700!

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Apr 9, 2008 | 01:32 PM

BigBadLou

Supreme Member

iTrader: (3)

Joined: Jul 2004

Posts: 2,989

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Car: '91 Z28 convertible

Engine: TPI

Transmission: T5

Axle/Gears: 3.27 posi disc

Re: 1991 Camaro RS - Tach Pegged Out when running

Good job!
Now that you have a bad driver board, would you be willing to donate it for good purposes? I would like to investigate whether it's possible to fix/revive these broken driver boards. I can adjust a working one but not sure how to fix a dead board.

Lou

Sep 14, 2008 | 06:29 PM

Renais

Junior Member

Joined: Feb 2007

Posts: 22

Likes: 0

From: Dayton, TN

Car: 1991 Camaro

Engine: 3.1L v6

Re: 1991 Camaro RS - Tach Pegged Out when running

Yeah, i've got the same problem

Only, mine stays pegged out even with the key off...when i crank, it jumps to 0 then goes around the tach until it pegs out again...in cold weather i can time when my car starts (it starts when the tach hits about 5500)

being an automatic, it's un-needed...but i'd like to have it working =/

Sep 15, 2008 | 09:54 AM

#10

90TNRS

Junior Member

Joined: Aug 2008

Posts: 6

Likes: 0

From: East Ridge Tn

Car: 1990 Camaro RS

Engine: 305 TBI

Transmission: 700R4

Axle/Gears: stock

Re: 1991 Camaro RS - Tach Pegged Out when running

mine goes to 0 when cranking then jumps up to about 4500 rpm for a couple seconds before finally pegging out

Apr 13, 2010 | 01:42 PM

#11

tylerv350

Junior Member

Joined: Apr 2010

Posts: 42

Likes: 0

From: Indianapolis, IN

Car: 1982 z28/rs... haha

Engine: 305(now) 333(soon)

Transmission: 350 3-speed automatic

Axle/Gears: 3.45 limited slip 10 bolt

Re: 1991 Camaro RS - Tach Pegged Out when running

i got the same problem on my '82 z28
yall know any good ways to just fix it directly and not super expensive?
thankss

Apr 13, 2010 | 01:47 PM

#12

micktroup2

Senior Member

Joined: Jul 2009

Posts: 752

Likes: 0

Car: 1991 Z28

Engine: 5.7 TPI

Transmission: 700R4

Re: 1991 Camaro RS - Tach Pegged Out when running

My previous response says it all. Go to a junk yard, pull a cluster- actually you don't even have to pull the cluster, just the bezel assembly- remove the circuit board(about 2 1/2 inches by 1 inch) and swap it into your cluster. If the new board is good it should cure the problem...