Third Generation F-Body Message Boards

Transmissions and Drivetrain Need help with your trans? Problems with your axle?

Tach reads double

Thread Tools
 
Search this Thread
 
Old 07-02-2018, 04:12 PM
  #1  
Junior Member
Thread Starter
 
Bruss's Avatar
 
Join Date: Jul 2018
Posts: 2
Likes: 0
Received 0 Likes on 0 Posts
Car: 1991 camaro rs
Engine: 350
Transmission: 700r4
Axle/Gears: 3.73
Tach reads double
I recently purchased a 1991 Camaro rs with a 350 bored. 40 over and 700r4 trans. It runs fine but the one thing that bugs me is that the tach is reading double the rpm. My mechanic said it had to do with the engine build but isn't sure how to fix it. Anyone have any thoughts.
Bruss is offline  
Reply Like
Old 07-02-2018, 04:17 PM
  #2  
Sponsor

iTrader: (92)
 
Tuned Performance's Avatar
 
Join Date: Dec 2004
Location: Mile High Country !!!
Posts: 15,408
Received 649 Likes on 573 Posts
Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: Tach reads double
https://www.thirdgen.org/forums/inte...w-90-92-v.html
Tuned Performance is offline  
Reply Like
Old 07-02-2018, 05:22 PM
  #3  
Moderator

iTrader: (1)
 
RBob's Avatar
 
Join Date: Mar 2002
Location: Chasing Electrons
Posts: 18,401
Likes: 0
Received 215 Likes on 201 Posts
Car: check
Engine: check
Transmission: check
Re: Tach reads double
Originally Posted by Bruss
I recently purchased a 1991 Camaro rs with a 350 bored. 40 over and 700r4 trans. It runs fine but the one thing that bugs me is that the tach is reading double the rpm. My mechanic said it had to do with the engine build but isn't sure how to fix it. Anyone have any thoughts.
On the electronics board here, in the stickies (up top), is a write up on how to fix the tach. Common problem, simple resistor.

RBob.
RBob is offline  
Reply Like
Old 07-02-2018, 05:28 PM
  #4  
Sponsor

iTrader: (92)
 
Tuned Performance's Avatar
 
Join Date: Dec 2004
Location: Mile High Country !!!
Posts: 15,408
Received 649 Likes on 573 Posts
Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: Tach reads double

The blue resistor iirc it’s 192k
Last edited by Tuned Performance; 07-02-2018 at 05:45 PM.
Tuned Performance is offline  
Reply Like
Old 07-02-2018, 05:47 PM
  #5  
Sponsor

iTrader: (92)
 
Tuned Performance's Avatar
 
Join Date: Dec 2004
Location: Mile High Country !!!
Posts: 15,408
Received 649 Likes on 573 Posts
Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: Tach reads double
https://www.thirdgen.org/forums/elec...meter-fix.html
Tuned Performance is offline  
Reply Like
Old 07-02-2018, 05:57 PM
  #6  
Sponsor

iTrader: (92)
 
Tuned Performance's Avatar
 
Join Date: Dec 2004
Location: Mile High Country !!!
Posts: 15,408
Received 649 Likes on 573 Posts
Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: Tach reads double
Send me a pm if you need one


Tuned Performance is offline  
Reply Like
Old 07-03-2018, 09:24 AM
  #7  
Junior Member
Thread Starter
 
Bruss's Avatar
 
Join Date: Jul 2018
Posts: 2
Likes: 0
Received 0 Likes on 0 Posts
Car: 1991 camaro rs
Engine: 350
Transmission: 700r4
Axle/Gears: 3.73
Re: Tach reads double
Originally Posted by Tuned Performance
Send me a pm if you need one


Is it difficult to install?
Bruss is offline  
Reply Like

Trending Topics

Old 07-03-2018, 11:43 AM
  #8  
Sponsor

iTrader: (92)
 
Tuned Performance's Avatar
 
Join Date: Dec 2004
Location: Mile High Country !!!
Posts: 15,408
Received 649 Likes on 573 Posts
Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: Tach reads double
No you just solder it on
Tuned Performance is offline  
Reply Like
Old 07-03-2018, 12:16 PM
  #9  
Supreme Member

 
mmadden55's Avatar
 
Join Date: Nov 2008
Location: Houson
Posts: 1,146
Received 6 Likes on 5 Posts
Car: 86 Firebird
Engine: 305 SBC
Transmission: 700 R4 TCI
Axle/Gears: 3.42
Re: Tach reads double
Auto meter instruments
mmadden55 is offline  
Reply Like
Old 07-03-2018, 12:27 PM
  #10  
Sponsor

iTrader: (92)
 
Tuned Performance's Avatar
 
Join Date: Dec 2004
Location: Mile High Country !!!
Posts: 15,408
Received 649 Likes on 573 Posts
Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: Tach reads double
Originally Posted by mmadden55
Auto meter instruments
Autometer makes a fix for the factory tach ?
Tuned Performance is offline  
Reply Like
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
1992 corvette tach reads "0", fuel gauge reads "0"
jmk1938
Electronics
1
06-26-2017 05:04 PM
Tach reads double rpm and timing light marks are way off
Mark P.
Electronics
3
04-07-2004 09:49 PM
Tach reads double and timing marks way off...any Ideas????????
Mark P.
Engine Swap
2
04-07-2004 12:25 AM
Tach reads double?
Fastmax
Electronics
1
01-24-2003 10:54 AM
factory tach reads double on a holley annialator ign
jcb999
Electronics
13
12-07-2002 08:25 PM
Back to Subforum
Transmissions and Drivetrain
View Next Unread
1983 firebird belhousing issue




Advanced Search
Quick Reply: Tach reads double


Reply Closed Thread Share

All times are GMT -5. The time now is 10:21 AM.