Timing Adjustment Myth?

[BlownAway]

I recently adjusted my timing without the shorting of the service connector. I had understood that the ECU would eventualy set it back, when adjusted this way. So far the timing is where I left it.
I haven't yet checked the timing with the service connector shorted. Would I get two different readings, shorted vs. unshorted?

[falconGSR]

You may or may not measure a difference in timing when sorting the service plug and not. It depends on what the sensors are telling the ecu about the atmosphere and the engine.

There is certainly some unresolved confusion on this topic. My Helms manual has not arrived and I don't know if the final answer is in there, but I imagine it is.

The real question is if making timing adjustments to the distributor is changing the base timing that the ecu compensates (it had better, because this is how everone is retarding their timing when they first install a JRSC), or does the ecu know where the timing is set and compensates for the distributor being too far advanced or retarded automatically, on top of adding/removing timing for changes in temperature, engine load, etc...

In either case, there seems to be no reason to play with the timing without shorting the service connector.

I did this last nite and could easily detect how moving the distributor was affecting the timing. I set the timing where I wanted it and killed the engine, pulled the wire, reset the ecu and restarted the engine.

I am running stock, and I advanced the timing a little to see if I noticed a difference. I haven't so far.

Then again, my butt dyno isin't calibrated.


[This message has been edited by falconGSR (edited December 06, 2000).]