Jeffrey,

Installing a FIDLE valve on a 420A is pretty straightforward. There are some generic instructions here:

http://www.megamanual.com/v22manual/mwire.htm#idle

Not all 420A/Neon’s have a stepper motor IAC. For those that do, though, the stepper IAC circuit is available as an option through our option service:

http://www.symtechlabs.com/catalog/megasquirt-option-service-p-43.html

The FIDLE driver is not compatible with a stepper motor IAC. If you would like to attempt to modify your ECU yourself to use a stepper motor IAC, please see step 26i here:

http://www.msextra.com/doc/ms2extra/build_manual.htm

Your MegaSquirt ECU currently uses the stepper motor driver for the tachometer output and general purpose outputs, so you will lose these functions if you install the stepper IAC circuit. You can, however, use the FIDLE circuit as a general purpose output and install a stand-alone tachometer output circuit.

Best regards,



SymTech Labs Support