As far as what tachs will work: buy a tach that has what is called an "inductive" pickup. this is a clip that you put around a spark plug wire, it will give your tach the signal it needs from the engine. the rest of the basic instructions, even though they wont be for your exact car, will be in the package with the tach.
If you have a dwell tach, the proper dwell is 50 degrees plus or minus two at 1500rpm. If you're too cheap to buy a dwell tach, set it at 0.016" and call it good. On my car, 50 degrees of dwell equals .009" gap. Dwell is the length of time, in degrees of crankshaft rotation, the points are open. Too little dwell and you're not getting spark long enough to properly burn the fuel. Too much dwell and you're just screwing up your plugs for no reason.
It should work. I have a 94 w/o a tach and put a LE version cluster with tach in. Works fine. There should still be a tach wire grouped into the harness plugs. Just unplug your old one and plug in the new one that's it.
It should work ok if the wire for the tach under the hood is connected and I don't remember which one it is.
Tach is driven by a motor signal, speedo is from the trans the sensor is bad on the transmission
It depends on the year. For quite a while the points could be accessed through a little hole on the side of the distributor cap. The points were installed "close enough" to get the engine started then you would use a "dwell tach" to set the points through the little hole. But for the record, newer GM engines don't use points. The "dwell tach" the previous poster is referring to is a combination tachometer and dwell meter that can be purchased at most auto parts stores. The points should be set for 30 degrees dwell. Most GM cars stopped using points and went to HEI around 1974.
There are two ways to do it: the cheap way and the right way.The cheap way is strictly with feeler gauges. You remove the distributor cap and rotor, rotate the engine until the points are all the way open, loosen the little screw holding the points in, gap the points to 0.016" and put the car back together. The right way also requires a dwell-tach. After you set the gap to .016, hook up the dwell-tach, put it in four cylinder mode, and start the engine. Put the instrument on TACH and adjust idle to 1500 rpm. Then put it on DWELL - the length of time, in degrees, the points are open. The dwell should be 50 degrees plus or minus two. If it's too short, the points are too far closed; if too long, they're too far open.
no
An inductive sensor depends on ferro-magnetism, which is a characteristic of certain metals, such as iron.
Bad white wire
The tachometer is fed from the distributor coil. High voltage spikes are filtered on the wire to prevent damage to the electronic display. There is a tach filter attached to the intake manifold. Replace this filter and your tach will work again. Mid-America Motorworks Part #618-561
Inductive order is starting from the bottom and working upward. Examples works of inductive order start with specific details of the event and work back to a more broad scenario.