Setting the timing on a Digifant engine is slightly different than other systems. Whereas most cars have the timing set with the engine at idle, Digifant timing is accomplished with the engine turning between 2000 and 2500 rpm. This fools a lot of professional mechanics and hobbyists alike who are experienced with CIS and CIS-E systems which must be timed at idle.
Before you set the timing, disconnect the blue coolant temperature sensor in the cylinder head coolant neck. Rev the engine through 2500 rpm four times to clear the control unit's memory. Loosen the distributor hold-down bolt. Watch out for the radiator fan which can come on at any time during this procedure.
Set the timing to 6 degrees +/- 1 degree before top dead center at approximately 2250 rpm. Tighten the distributor hold-down bolt, and rev the engine through 3000 rpm three times.
Now you should check and reset your idle speed if necessary. The correct idle with the coolant temperature sensor disconnected is 900 to 1000 rpm. With the sensor connected normal idle should drop to 800 +/- 50 rpm.
For Digifant I cars only, you must reset the control unit to its base setting after adjusting the timing. See your factory manual.
Although some cars respond to advanced timing, Digifant does not and needs to be timed to the factory setting for peak performance and to avoid ping. Even with the correct timing, Digifant cars run best on 92 octane fuel or better and may still ping on hot days due to hot spots in the cylinder head.
Temporary solutions to hot weather ping include increasing the amount of water in your antifreeze mix, adding a surfactant (wetting agent) to the coolant such as Red Line's Water Wetter, installing a lower temperature thermostat.
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