Just a quick question regarding the timing on my 1989 five litre.
I warm up the engine pull the spout connector and set the base timing at 10 degrees.
When I replug the spout connector back in the revs rise a small amount.
Is this normal or should it not be affected at idle.
Thanks for your replies.

 

You should warm it up, shut it off and pull the spout plug. Then hook up your light and start it back up and set it to 10° btdc or up to 14° for a bit more performance. Then shut it off, reconnect the spout plug. Idle speed should not be affected by setting the timing. Mine was way retarted before and now its at 14° idles the same either way.

It also helps greatly to clean up your harmonic balancer and put a white mark at 10° btdc. I used a white out pen

 

If the truck isnt shut off it will raise the idle a little when you plug the spout connector back in. But it should be back to normal the next time you start it. Its not something to be worried about.