I have recently rebuilt a 2.8 V6 and when trying to set the timing it retards instead of advances under acceleration. What could cause this

Bypass connected? Brown/black wire, pass toeboard? should be hooked together to place CCC into ECM control. With the bypass enabled, wire connector open/unhooked, ignition timing is set.

Thanks, that helped, but I still have some backfiring thru the intake manifold. What could be causung this?

I've posted a thread on your timing prob you might want to keep an eye on it.


http://www.hotrodders.com/forum/retarded-timing-133990.html



Doug

Thanks, that helped, but I still have some backfiring thru the intake manifold. What could be causung this?Disconnect the bypass connector and at idle at operating temperature, use a timing light and adjust initial timing as normal, read hood emissions sticker.

After setting, turn off engine, reconnect bypass connector, disconnect battery for 20-30 seconds, reconnect battery and start the engine. It will relearn the engine operating conditions needed.

It's backfiring because it's retarded. I bought a 1991 motor home, and someone set the timing without disconnecting the brown bypass connector. It was 20 degrees retarded.
David