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OBD1 8bit Fuel

Given table value ''v'' and multiplier value ''m'', the fuel value as seen in a ROM editor is: Fuel(''v'',''m'') = ''vm''/4 The result is presumably proportional...

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Adapted from pgmfi.org wiki

Given table value ''v'' and multiplier value ''m'', the fuel value as seen in a ROM editor is: Fuel(''v'',''m'') = ''v*m''/4


The result is presumably proportional to the amount of fuel entering the engine. It has an effective range of 0-16256.25 -- so how does this relate to injector duty cycle? Pulse width (ms) = PW = (''vm''/4)/100 + 0.60ms = ''vm''/400 + 0.60ms Max Duty Cycle is (((1000602/rpm)0.9ms) Duty Cycle = PW/TRPM = (''vm''/400 + 0.60)/(60000/''RPM'') Simplifying, Duty Cycle = ''RPM''(''vm'' + 240)/24000000 This is based upon information provided by Didier Pelegri and not verified by myself.--AndySloane

Credits and source

Source Adapted from OBD1 8bit Fuel on pgmfi.org wiki. Licensed under CC BY-NC-SA 1.0.