Hi!

I'm up to trying to adjust the timing in a 1991 Chevy Van G20 5.7L V8.
I have both general and specific questions on timinig adjustment but I'll start from a general one.

- I'm following the procedure of the label under the hood in order to check the timing: warm up the engine, don't touch the idle, remove the timing connector, get the flash from the 1st spark plug wire...
When I do this the notch on the crankshaft pulley is visible and right below the marker notches (which notch exactly represents TDC would be one of the specific questions but for that I want to be able to show a picture first).
However, if I reconnect the timing connector and check the timing again, the notch is not visible anymore. The pulley looks still static, but there is no sign of the line anywhere near the marker.

What I think is that the electronic timing control is automatically moving it from TDC according to whatever it learned in the long run and short run indicators of advance, right? but could it be that far off? Is it worth to reset the ECU after the timing adjustment?

Thanks!

 

yeah i know it automatically advances timing

where did you find your timing connector

 

Just next to the driver's seat, close to the distributor. A single wire connector, color tan and black. So, is it normal that the time is changed that much by the ETC?

The last smog check that it failed was telling me that it was running lean (retarded timing). But I know that it closes the loop, hopefully, meaning that the problem is somewhere else.