Timing?

[JMR_AW11]

It's best to fit the service link

Without the link the ignition timing will be affected by coolant temperature.
If the engine is warm (and no service link fitted) the timing will be approx 16 deg BTDC at idle. Whilst cold, the timing will be much more advanced than 16degC.

Also without the link the ECU will increase the advance in short bursts if the idle rpm falters. This will tend to make the timing look fuzzy with a timing light if the revs drop.

Also the ignition timing will be rpm dependent without the service link.

Make sure you keep your foot off the throttle as the 10 deg service timing only applies with the link fitted and your foot off the throttle.

Obviously, once you have set the timing you should REMOVE the service link.

(data correct for UK AW11 4A-GE so should be similar for AE86)