2000 LaSabre Intermittent CPS-Crank Posistion Sensor DTC P0336 error

[Zoomer_55]

Hey all - 2000 LaSabre has 187,000 miles on it,
I have read some of the post on this but I still have a few questions.1st the problem(s).
I noticed that once in a while that tachometer was not working but stop and re-start and it worked.
Then I had the occasional miss-fire at highway speeds.
I had one hard starting event that requiring gas peddle to the floor and a little pumping.
Then Service Engine Soon (SES) light came on and diagnostic said it was P0336 CPS error.

So far I have visually inspected the CPS (behind crank pulley) and connector. It is as dry as a bone and wires look in good shape.
I re-seated the CPS connector and SES light went out on starting.

I took a trip 700 miles RT and noticed that car ran fine most of the time and got similar mileage to what I was getting previously. After driving for an hour or so I would get a misfire and the Tach would stop working but I did not get SES light going on. Stop for coffee and when I re-started the engine the Tach works fine. Then 45 to 60 Min. later notice the Tach stopped working but no miss-fire this time. Then again with miss-fires every houir. Every time it miss-fires the tach stops working.

Question: I have read that CPS either works or it doesn't (if not working the car won't start).
Before CPS is 100% dead can it be heat sensitive and become intermittent like it is acting now?
What does tach have to do with CPS sensor working properly? Seems related with miss-fire causing Tach failure.

Before I pull off harmonic pulley and change CPS it would be nice to have some certainty the CPS probably the problem.
Anywhere else I should be looking? or that would cause P0336 CPS error?
Thanks Bill

 

[HotZ28]

http://easyautodiagnostics.com/gm_ignition_3800/test_ignition_module_1.php

 

[gmfugitt]

It may to too late too help you. Hopefully this helps someone else. I have a 2000 Lesabre with 120000 at the time. The tachometer would drop to 0 occasionally (once a week) for about six months. The tach would work when the car was restarted. The code for random misfire would set monthly. The car also died a couple of times when driving. I could not find the problem. Finally the code for CPS set. I immediately replaced it and have not had any problems for the past year.