Tachometer problem

[vintageracer]

I searched the archives and did not find and answer to my problem.

The factory tach on my 87 GN pegs to the right immediately upon starting the car. Almost like it goes to complete ground.

What causes this and how do you fix this problem?

 

[garyk1970]

look behind alternator,there should be green and black plugs there,unplug them,they are fuel pump and tach test leads.
maybe thats it.

 

[jretrodude]

make sure your map sensor is there

Make sure your map sensor is there or connected and check the vaccum line make sure it's not cracked or came off.

 

[Roger]

Caspers repairs these.

 

[GNVenom]

Read up:

http://www.installationinstructions.com/FYI/tachboost.pdf

 

[vintageracer]

Thanks for everyone for the help, direction and advice.

I will get to work on the problem tomorrow.

 

[mikestertwo]

Put a tach on your test point connector located near the back of the alternator. If it reads correct, your factory tach is bad. Send it to Caspers for repair.