Timing adjustment on a 95 Chevy 4x4

Question

I changed the intake manifold gasket on my 95 Chevy 4x4. In order to do that, I had to remove the distributor. I did everything right, marked TDC on the distributor, made sure the rotor was set at TDC and even marked the distributor so I could line it back up with the intake manifold. Stupid me though.....cleaned off the mark I made on the intake manifold. I put it back pretty close to where it was but it obviously isn't perfect because the timing is off. I fixed the leak though....lol. With the ac off and at idle, it's at 8 degrees BTDC and when I disconnected the "set timing connector" it was about 16 degrees ATDC. My 3 questions are the following:

1: Am I going to want to turn the distributor clockwise or counterclockwise to correct this? I think counterclockwise about a 1/4" should put it back to where it was

2: Do the degrees on the dampner (where you shoot the timing light) match the degrees turned on the distributor? In other words, say the timing mark is roughly 16 degrees ATDC, do I turn the distributor 16 degrees counterclockwise?

3: Why, since my truck has a camshaft position sensor, does it matter how the distributor is set? It seems to me that if the computer already knows where TDC is from the camshaft position sensor, shouldn't it tell the distributor when to fire at the proper time too? Or is that too complex to write a computer code to do that?

Answer 1

1. Counter-clockwise.

2.  The timing marks on the damper correspond with the distributor's timing.

3.  The distributor is mechanical, and is not controlled by the ECU, unlike a distributorless ignition system, in which the timing IS controlled by the ECU.

The camshaft position sensor is used on your vehicle by the ECU to tell the fuel injectors when to open and close.

Answer 2

Time it the old fashioned way.

1. Remove the distributor.

2. Remove # 1 spark plug.

3. Have someone bump the starter. Allow #1 piston to come all the way     up on the compression stroke.

4. Install distributor.

5. Replace spark plug.

6. Good to go