tach problems

[rgoss]

I have a 94 accord lx with 64,000 miles. I having a problem with the tach. Above 2500 rpm it works fine. Below 2500 rpm the tach does not operatate smoothly, it seems to jump in 300 to 400 rpm increment. Sometimes it will drop down to idle other times it won't drop below 1500 rpm. Any suggestions to what the problem may be would greatly appreciated.

[princess]

Does it also make a noise??

Is there a difference on whether it's cold or up to running temp?

[rgoss]

There is no noise. It does it hot or cold.

[hondacuraworld]

Does the tach jump correspond with the engine, or is it just the tachometer that is reading in error?

[rgoss]

The tach jump corresponds with the engine. At idle it reads in error. It doesn't always drop to idle rpm, it will stay at 1500 rpm

[hondacuraworld]

Assuming that you don't have a MIL (check engine light), we have to assume that the problem is not electronic or sensor related in nature.

Does this happen only when the car is driving, or will it happen if you rev the engine with the car in neutral/park?

[raff]

have the gauges been changed before? if it has that could be your problem. some of those aftermarket gauges require that you pop off your "needles" so that you can fit the new gauges in properly. if that is the case then you gotta play with the needle and hope to god that it fixes itself... haha that's what i did for my friends car atleast :)

[rgoss]

As far as I know the guages have not been changed. It seems to be worse when I rev the engine with the car in park or neutral than when driving.

[hondacuraworld]

This sounds pretty complex to be diagnosing....at least from my end :(

Time to bring it in to the dealer I'm afraid.......

[BenjiBoy650]

You say that the tach mostly corresponds to the engine, except at idle, where sometimes it stays at 1500. From my point of view, your engine is at 1500. It's jumping around below 2500, so it might just be idling at 1500. Have you looked at your air filter lately?