Aftermarket RPM meter problem

[Flamethrower]

hiya guys.
I have a small problem with my Rpm Meter . ITS installed in my 2005 Alto VXR (1000cc).Well the problem is that the rpm needle is a bit slow . i mean when you push the accelerator on neutral . the engine races i.e the engine sound gets louder but it takes about 4-5 seconds for the rpm to rises.the same occurs when you remove your foot from the pedal.
Why is this So ??
And how could i fix it up??

[system]

Are u using the tachometer which connects with the spark plug leads? or are u sing some mechanically connected one? Was it ok before or has it developed a fault recently? I can give some comments if I know the above.

[FLi_GTi]

Check at the back of the tacho for a switch that switches impedence usually to alow operation with a particular number of cylinders. Its marked 3,4,6 on most tachos. Most probably thats what is causing a faulty reading.

[Flamethrower]

@ Mehran.
Yup.i AM using the tachometer which connects with the spark plug leads ( I think so ) . U know that One of the plug wires which ends at the thingie on the car's body ....To the right of the battery.See the pics to get a glimpse Although this is not the engine i have but somehow u will know it.
it was just like dat since the day i got it fitted.

@ FLi_GTi
The switch is marked at 3

[robin]

what i got from FLi_GTi's reply is that Alto has got a 4 cylinder engine so switch to position 4.

[Flamethrower]

Tried it ...
Unfortunately,it much slowly at 4 ...

[system]

It may be possible that the insulation on the rpm meter leads is thick which can probably cause less flux to be generated into the rpm leads. My suggestion would be try to check this meter on another car. That would give u an idea about its performance with another car. If u have a manual(book) about the meter then u could check if the connections have been made correctly or not.