You can mark it however you want, but it's best to measure it at the crank and adjust the tab to match the crank.

 

I'm not sure I follow the coat hanger method.

By making a mark on the waterpump where 10* stock according to the timing tab (in its stock location) followed by adjusting stock TDC on the balancer to this mark isn't that measuring by the crank?

 

There's a huge difference.

One way there is still a possible influence by the ECM that might be shifting the actual advance. There are scalers and offsets that could change the timing from what is in the table. Ideally the value in the table will be what is at the crank, but I have found this to be rarely correct, without first verifying actual base timing with no ECM influence (bypass disconnected).

Depending on how the mechanics are set up and how the code is set-up a value of 0 entered in the table may not actually be able to get to an advance of of 0 at the crank, and there's still the issue of offsets that can cause a change in the commanded SA value.

Why wouldn't someone follow the GM outlined procedure for checking timing? It's simple and quicker than programming EEPROMs for different SA table, or even using an emulator/flash based ECM to change full tables, that can give you false results. On many cars I replace the connector in the tan/block wire with an actual switch, to make it even easier to check timing.

I don't understand why you want to use a coat hanger to create a timing tab, when there's a perfectly good one on the engine already, that is set correctly (or very close to) from the factory so that when the timing mark lines up with the timing tab at 0*, the #1 piston is in fact at TDC. You start moving away from that and you could be setting yourself up for induced errors.

This is why I ALWAYS make the sensor mount adjustable, so that no modification to the timing tab or balancer are needed.

If your sensor is not adjustable you will have to make new timing marks in order to get it set-up properly, but is not a method I like, because you're not referencing the original TDC at that point and are assuming that you understand the system correctly.

 

My sensor is adjustable...I'm pretty sure all I have to do is make a mark on my waterpump where the original 10* mark is...then just move TDC to it...via adjustment.

I had marked the exact location of the tab...before removing it so I am 100% sure it is back to where it once was.

 

No, if you can move the sensor, the best way to do it is move the sensor, just you would move the dizzy to set timing. Otherwise you're lying to yourself to see the numbers you want to see, instead of what the actual numbers are.

 

That's what I'm saying. Mark where original 10* is on waterpump...move sensor and timing tab until TDC from trigger is at the 10* mark on water pump.

This makes TDC of trigger wheel (and crank) line up with 10* original location of timing tab.

 

It's always been what I put in the table for me at temp.

His sensor is on the tab. If and when he adjusts it he needs a reference.

 

I really don't know what the water pump has to do with this.

Can you post some detailed pictures of your set-up, if bl85c is correct and you are using the timing marker as the adjustable mount, that is a poor design, because now your reference can no longer be a reference.

You really should have the sensor independent of the timing tab, so that you can use the original reference marks to verify actual timing.

Just because yours is, does not automatically mean that every one else's is. I have found that I usually need to adjust some scalers by a few degrees to get SA to line up exactly with what the ECM is telling me the SA should be.

The best way to find base timing is to find base timing, meaning disconnect the bypass wire, anything else is inviting error into the equation.

 

LOL nobody's debating the way I did it on the 2.8 was anti-engineering, but it was simple and got the job done.

 

Same spark plug wires, no distributor definitely tons smoother. I don't see why some people say there isn't much difference between DIS and distributor. My car feels like a completely different vehicle -_-

I had a new distributor (ACDelco), new cap, rotor, wires, and all that and there is still worlds of difference.