69 Tach Calibration - Team Camaro Tech
Electrical & Wiring Troubleshooting electrical.

 
LinkBack Thread Tools Display Modes
post #1 of 8 (permalink) Old Dec 13th, 06, 04:22 AM Thread Starter
Senior Tech
Jim
 
Join Date: Aug 2004
Location: Flemington, New Jersey
Posts: 517
69 Tach Calibration

My tach is off by 1-2 hundred RPMS. Is there an adjustment or do I live with it?
Schoon

Schoon
SCHOON is offline  
Sponsored Links
Advertisement
 
post #2 of 8 (permalink) Old Dec 13th, 06, 07:10 AM
Senior Tech
Dave
 
Join Date: Apr 2001
Location: Southern NH
Posts: 1,068
Re: 69 Tach Calibration

I have the same problem with mine. Some people say there is an djustment on the tach itself, but I haven't taken mine out to find out. Hopefully will have time before spring. There was a post a couple of months ago about it.
Dave69Z is offline  
post #3 of 8 (permalink) Old Dec 13th, 06, 12:54 PM
Gold Lifetime Member
Fred
 
Join Date: Nov 2006
Location: Seabeck WA
Posts: 8,375
Re: 69 Tach Calibration

If there's an adjustment I never found it. When my car was new, one of the things on my corrections list for my dealer was to calibrate the tach. It was 300 rpm too fast. Also it had a loud lifter. (solid cam, 375hp) What else? Hey, I'm trying to remember, it's been 37 years!
Oh yeah, the front-end was way out of alignment. And there was a rust spot boiling up on the top of the front fender UNDER the paint. I made an appointment and dropped the car off. After work I picked up the car. Rust spot still there. Tach still read 300rpm. Started the engine. Lifter still knocked. I said 'did you even fix the alignment?'. They said, that's not covered. I said 'What is?'. They were out of business within a year.
Oh yeah, the tach! Three years later I took the tach out looking for an adjustment. Never found it, but did manage to stick something into the spring return and ruin it. A new one cost $70.00 and corrected the problem.

One owner 69 Camaro,(yep, bought it new
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
)
RS SS Hugger Orange, L88, 4:10's tru-tack posi, ducted hood, Endura, spoilers.
TH400 (CX) with Coan 8" converter, GV-OD, 8 track still on console and best et 10.495,
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
128.79mph 1.428 60'
All with 1960's stuff. (except tires and converter)
+ MT Super Scavenger headers & 3" full exhaust with X pipe. 3700 lbs. with me in it.
1000cfm AED and HD Harold-Lunati SR, 725 lift with shaft rockers too.
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Fred Ficarra is offline  
 
post #4 of 8 (permalink) Old Dec 14th, 06, 06:52 AM
Senior Tech
Dave
 
Join Date: Apr 2001
Location: Southern NH
Posts: 1,068
Re: 69 Tach Calibration

So it sounds like you never found the adjustment and had to buy a new tach. I am considering sending mine out for calibration but get a little worried about shipping it. For the cost i could probably buy and oer tach and install it if it works correctly? Anyone ever tried this?
Dave69Z is offline  
post #5 of 8 (permalink) Old Dec 14th, 06, 02:11 PM
Senior Tech
 
Join Date: Mar 2002
Location: Austin, TX, USA
Posts: 5,277
Re: 69 Tach Calibration

FWIW: I have looked at the guts of the OEM tach. They use a hybrid circuit with conductive ink resistors. If I recall, the adjustment was a laser trimming operation that partially cuts through the resitor ink. No tweaker to adjust. Perhaps other years were different.

Dave
========================
68 Coupe, 350 w/ Edelbrock Performer RPM heads, cam, intake, 700R4, Dave's small body HEI
dnult is offline  
post #6 of 8 (permalink) Old Dec 14th, 06, 02:37 PM
Gold Lifetime Member
Fred
 
Join Date: Nov 2006
Location: Seabeck WA
Posts: 8,375
Re: 69 Tach Calibration

Speaking of lasers,,, the ash tray light is fiber-optics. I'm sure everyone knows that. I thought the laser was invented later???? Nope, It's coming back to me. Apollo 11 planted a laser reflector on the Moon. July of 69.
Results just in! The Moon is moving away from the Earth at the rate of 2" a year. That's faster than continental drift!
What were we talking about?!

One owner 69 Camaro,(yep, bought it new
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
)
RS SS Hugger Orange, L88, 4:10's tru-tack posi, ducted hood, Endura, spoilers.
TH400 (CX) with Coan 8" converter, GV-OD, 8 track still on console and best et 10.495,
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
128.79mph 1.428 60'
All with 1960's stuff. (except tires and converter)
+ MT Super Scavenger headers & 3" full exhaust with X pipe. 3700 lbs. with me in it.
1000cfm AED and HD Harold-Lunati SR, 725 lift with shaft rockers too.
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Fred Ficarra is offline  
post #7 of 8 (permalink) Old Dec 14th, 06, 04:24 PM
Gold Lifetime Member
Steve
 
Farm Boy's Avatar
 
Join Date: Feb 2005
Location: The California Republic
Posts: 1,754
Re: 69 Tach Calibration

I adjusted the tach in my 67 and it works great! These old tachometers have a calibration potentiometer on the circuit board that can be accessed through a hole in the back of the tach. The adjustment hole was covered with a small round sticker. I removed the tach but I think the adjustment can be accomplished with the tach in the dash. You can use a small plastic screwdriver to make the adjustment (to avoid shorting out the circuits inside the tach). You can get a small plastic screwdriver at Radio Shack.




Steve

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

I drove it for the first time in 1972 when I was 15.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Better looking than a '56 Ford or Plymouth.
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Farm Boy is offline  
post #8 of 8 (permalink) Old Dec 15th, 06, 09:04 AM
Senior Tech
 
Join Date: Mar 2002
Location: Austin, TX, USA
Posts: 5,277
Re: 69 Tach Calibration

Thanks for sharing that Farm Boy. Now I'm wondering what model year tach that was I worked on. I know the back of the tach was a round protruding stamped metal piece about 1.5" in diameter with three terminals sticking out of it. The hybrid circuit board inside was about 1.25" in diameter. At the moment I can't recall if the tach was round or square. A mind is a terrible thing to waste.

I'll have to add yours to my photo collection.

Dave
========================
68 Coupe, 350 w/ Edelbrock Performer RPM heads, cam, intake, 700R4, Dave's small body HEI
dnult is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Team Camaro Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address.
NOTE we receive a lot of registrations with bad email addresses. IF you do not receive your confirmation email you will not be able to post. contact support and we will try and help.
Be sure you enter a valid email address and check your spam folder as well.



Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
tach problem MYSNAKES Troubleshooting 3 Dec 8th, 05 06:52 PM
Tach Problem On 1986 Iroc MYSNAKES Electrical & Wiring 2 Dec 7th, 05 06:02 PM
68 tach dirkey Electrical & Wiring 2 May 16th, 05 07:39 PM
adding a tach and guages.. 1968 327 timbo68 Performance 0 May 9th, 05 04:28 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome