Timing Will Not Advance Properly VAST System

The following checks assume that the engine runs but timing will not advance.

The design of the VAST system will allow the ignition system to function at initial timing in the event that the IGt signal does not reach the igniter. If this condition occurs, the ignition system will be locked at initial timing regardless of engine speed or load. The ECU has no way to monitor for this fault, so there will be no indication of this condition other than a loss of engine performance.

To check for this condition:

1) Monitor the IGt wire at the igniter using an oscilloscope or logic probe.

2) If a good signal is being sent out on IGt, check the connection at the igniter.

3) Once connections are confirmed, the igniter is the last item left which can cause the problem.

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