Does the injection pump operate the tac?
I was driving and the tac dropped from 3000 Rpm to 0 rpm and it started running rough and white smoking from time to time it will kick in and the tac works and i can get up to speed. I'm stumped on this one cause i just replaced the crank senser and it worked great for a day then the next day it was messing up again.

 

Are you sure you installed the Crank sensor correct?
The tach going dead in your 99 IS the crank sensor. Or you got a defective one or there might be a different problem.

I'd suggest you take out the crank sensor and check it. Is it chewed up?
( The tip that goes inside the block )( When you took out the old sensor, was that one chewed up? )
If so then there has been contact between the tone ring and the sensor.
Not good. The tone ring is bolted onto the crankshaft.....

I hope for you that you got simply a DOA sensor!

Marco