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MS1-ExtraMegaSquirt v3.0 with Toyota
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Please Note:
All of these instructions / diagrams are to be used at your own risk, like most things there is more than one way to do the same thing, what we have tried to do is to offer a method that we have tested or that others have tested for us. No warranty expressed or implied. Use at your own risk. |
Toyota's variable advance spark timing system (VAST) was used on Toyota vehicles in the mid '80s through early '90s.. The MR2, Celica, Toyota pickup, and Toyota 4runner use VAST (~1985-1993) The VAST system is only used on the 2S-E, 22R-E, 22R-TE, 4Y-E and 4A-GE engines.
VAST uses four main signals to control ignition timing. Two of these are used with MegaSquirt 1 with MSnS-Extra.
Ne: The engine speed and crankshaft position input is derived from a VR sensor and conditioned as the Ne output 0 to +12V square wave. This signal is fed to the Tach input of MegaSquirt. Because of the conditioning by the Igniter this signal may be fed to the Hall sensor input of MegaSquirt.
IGt: The spark timing and dwell signal from MegaSquirt is the input for IGt and drives the coil. The requirements for this signal may vary depending on the VAST system. Sufficient current from the MegaSquirt output must be available to drive Q1 on the diagram.
