AEM 30-3903 Infinity Plug & Play Harnesses - Volkswagen 2002-2005 MKIV Golf/Jetta 1.8T - Manual (Page 20)

3903-MKIV 1.8T 20
© 2014 AEM Performance Electronics
Ignition Sync
Proper ignition sync ensures that the commanded timing in the software is actually the ignition timing value
delivered to the engine. For example, when commanding 10° of timing advance in the software, there should be
10° of timing advance at the engine when checked with a timing light. The ignition sync has already been set in
the VW 1.8T base session and should not require adjustment, however, it is always good practice to verify proper
ignition sync.
The 1.8T engine has its ignition timing checked on the flywheel instead of on
the crank pulley. Locate the timing mark viewing hole in the top of the
bellhousing near the back of the cylinder block and remove the access plug.
The air intake tract may need to be temporarily removed in order to gain line of
sight to the timing mark with a timing light.
The correct way to trigger a timing light is to put the inductive pickup on a high
voltage secondary ignition wire. On a coil-on-plug arrangement, this means
removing coil #1 from its well and using a spark plug wire between the coil and
the spark plug. Do not attempt to trigger the timing light off of the low voltage
trigger wires going into the coil. Doing so may cause incorrect readings with
the timing light which may ultimately result in an incorrect ignition sync
adjustment.
Once the Drive By Wire Wizard has been completed, the engine can be
started and idled. In the Setup Wizard, go to the Ignition Sync Wizard. Lock
the timing at a value that can be easily verified. If using a non-dial back timing light, lock the timing at 0°; if using a
dial back timing light, set the timing to a value that will allow the engine to idle easily (10° or 15°, etc) and set the
dial back to the same amount. Check that the timing mark on the flywheel lines up with the pointer in the
bellhousing. If the indicated timing is off from the pointer, use the Advance or Retard Timing buttons in the until the
ignition sync is correct. Unlock the timing once the ignition sync has been verified.