AEM 30-6905 Universal Programmable EMS-4 - Manual (Page 146)

Page 146 of 279 EMS-4 Install and Tuning Guide_Rev 1.6
common preventative measure for eliminating “noise” is to twist the wires together to minimize
the electromagnetic field near the wires.
On any EFI system, resistive spark plug leads are REQUIRED to suppress noise!
Common resistive spark plug leads include those with a carbon impregnated fiberglass core or
spiral wound filament around a carbon core wire.
Another source of noise that can cause a misfire is an electrical “leak” in a plug wire or boot.
Even a very small pinhole in a spark plug insulator or boot will allow electricity to arc to the
cylinder head and interfere with the ECU signal.
When the timing pattern inputs are correct, it‟s time to move on to ignition synchronization.
Ignition Synchronization
The ignition timing measured with a timing light must be synchronized with the displayed value
in AEM Tuner. This is one of the most important steps in the setup process. Without it, the
commanded ignition timing may not be accurate.
It‟s a good idea to disable the fuel injectors and/or fuel pump during this step as well. Until the
timing is sync‟d, it doesn‟t make any sense to inject fuel just to fire it at the wrong time. The
ignition coil(s) must be connected and in working order.
Ignition Timing Sync Wizard
Go to Wizards
– Ignition Timing Sync Wizard. The purpose of the Timing Sync Wizard is to
synchronize the actual ignition timing with the value commanded by the EMS.