1st post. Novice. As I understand it:
The GM Command Control Carburetor (CCC) uses an ECM to control a Mixture Control Solenoid (MCS) that operates a paddle with two small spring-loaded metering rods, cycling at 10 Hertz, duty cycle fixed. Ground applied, the magnetic field pulls the plunger (and paddles and metering rods) down into the main jets, leaning out the mixture. Ground circuit de-energized the springs push the metering rods out of the jets, going to full rich. The length of time the MCS is on or off, plunger up or down, is varied by the ECM signal, depending on inputs from the O2 sensor.
A dwell meter can measure the computer control signal, 30˚ being half the time up, half the time down, as the computer uses the inputs from the O2 sensor to try to maintain a stoichiometric air fuel mixture. It varies the time up or down, according to the air fuel ratio detected in the exhaust.
I would like to run the CCC Quadrajet carburetor but without the ECM, to be able to visually read an air-fuel meter gauge to make changes on the fly while in light cruise mode, so that I can run different blends of gasoline to ethanol fuel and also, since ethanol is more resistant to lean mixtures without causing detonation issues than gasoline, I would like to run the engine as lean as the engine will allow by manually leaning it from the driver's seat for maximum fuel economy.
What type of device could take the place of the ECM to energize and de-energize the MCS at the same 10 hertz cycle and allow manual variability?
It has been suggested to vary the voltage input that normally comes from the O2 sensor and run that into the ECM, but prefer not to have a computer at all for simplicity's sake, as it easily goes into default open-loop mode meaning no MCS operation, full rich in the primaries, when it detects an anomaly.
I appreciate your input.
The GM Command Control Carburetor (CCC) uses an ECM to control a Mixture Control Solenoid (MCS) that operates a paddle with two small spring-loaded metering rods, cycling at 10 Hertz, duty cycle fixed. Ground applied, the magnetic field pulls the plunger (and paddles and metering rods) down into the main jets, leaning out the mixture. Ground circuit de-energized the springs push the metering rods out of the jets, going to full rich. The length of time the MCS is on or off, plunger up or down, is varied by the ECM signal, depending on inputs from the O2 sensor.
A dwell meter can measure the computer control signal, 30˚ being half the time up, half the time down, as the computer uses the inputs from the O2 sensor to try to maintain a stoichiometric air fuel mixture. It varies the time up or down, according to the air fuel ratio detected in the exhaust.
I would like to run the CCC Quadrajet carburetor but without the ECM, to be able to visually read an air-fuel meter gauge to make changes on the fly while in light cruise mode, so that I can run different blends of gasoline to ethanol fuel and also, since ethanol is more resistant to lean mixtures without causing detonation issues than gasoline, I would like to run the engine as lean as the engine will allow by manually leaning it from the driver's seat for maximum fuel economy.
What type of device could take the place of the ECM to energize and de-energize the MCS at the same 10 hertz cycle and allow manual variability?
It has been suggested to vary the voltage input that normally comes from the O2 sensor and run that into the ECM, but prefer not to have a computer at all for simplicity's sake, as it easily goes into default open-loop mode meaning no MCS operation, full rich in the primaries, when it detects an anomaly.
I appreciate your input.