Timing control yes/no ??

[a67]

I'm curious if this is similar to how the throttle body fuel injection setups control timing and\or mechanical distributors? Or will the brains of the FI setup advance and retard a distributor based on programmed parameters? What distributors do you use with the FI setups that control timing as well? I'm considering a swap to EFI and this is something I'd like to keep or incorporate because it really enhances street driving.

I used a stock GM computer controlled distributor, small cap. GM also used large cap computer controlled distributors. The base distributor timing is set with a light with a running engine and the EST/BYPASS connector open. Usually in the 6° to 10° degree range. This sets up the cranking timing.

Once the engine is over 400 RPM the ECM takes over timing. Newer GM systems can also control the cranking timing. The actual timing can be retarded some from the base setting, and advanced by more. Usually in the -3° through +42° from the base setting. This is a limitation of the distributor to prevent cross firing.

The actual timing that gets used is pulled from various tables. The main spark table is based on RPM and MAP (load). Then there are other tables that are based on items such as engine coolant temperature and load. Then intake air temperature, and the detonation detection system.

Bob.