I have small problem with RPM clock! When I hit throttle and release it pointer is falling down slowly bit by bit ( she is stuck for a second every 4-5 millimeters)!

Do you know what is the issue here? maybe mechanism inside needs cleaning?

 

If you rev up the motor to near red line and then switch off the motor ,
does the needle drop smooth or does it stick on the way down ?

 

I tried now and needle stayed in 6500,6400 rpm. What does this mean?

EDIT: I also noticed when the engine is hot needle is also sticking but much less!

 

The spring on the meter movement has broken .
Thats my guess from half a world away .

Can someone else close to their car do the same test please ?
Does the needle stay or does it swing back to the low end peg when the motor is turned off ?

 

If you tap the glass , does the needle move ?

 

yes it moves.It` s coming down

 

I take back what I said about the spring being broken .
Your testing it by tapping ...
My new guess is that the movement is sticky .
Foreign matter or gummed up lube .
Its not the signal to the tachometer making it jumpy .
The fault is in the meter movement itself .
You can pull the cover off and have a look see at the movement ?

 

Check this out:
I made little test now. When the car is COLD needle movement is disaster, also when I hit the throttle and turn off engine needle stay on 6500 +/- RPM.
When the car is on normal running temp. needle behavior is much,much better. it is sticking oh her way down but much less! And when I hit the throttle and turn off engine needle comes all the way down...

This is insane!

 

Some new lube for the movement bearings would not hurt .

 

That is inside clock or?

 

Does anyone know how RPM clock is connected? Through computer or ignition coils? I also have board computer in it!

Thank you

 

In case I can say goodbye to my REV counter does anyone know can I use 993 REV counter? I found two of them in LA dismantler! HERE and HERE

Thank you

 

I think your old tachometer just needs a little oil .
Please do not do business with L.A. auto dismantler ,
they are not good people .

 

really? I did some business 2 times and I was more than satisfied!

BTW I solve tacho problem. Little shaking, hitting, contact spray and it`s working

 

Thanks for the tips Indycam.

When I pull out my tacho, is it easy to access the internals of the rpm tach guage to give it a clean and oil?