Fuel Metering Control Valve.
This was one of the earliest discoveries in the experiment. Yes, they function the same.
These solenoids recieve 12 volts, then they are negatively triggered, via PWM signal from ECM. Operating frequency is around 180Hz, with the duty cycle ranging from 5% to 40%.
De-energized = Low fuel volume into pump.
Energized = High fuel volume into pump.
.
The CP3 and CP4.1 pump's FMC valves are quite different in physical size. Fortunately, the coils have the same resistance.
.
TDIMiester - yes, you are correct. The graph simply shows the relationship between "specified" and "actual" pressure in the rail. VCDS sample rate is not nearly fast enough to measure the pressure wave fluctuations. PM me if you are interested in the "Full" VCDS data, in excel. (if any one knows how to post Excel here, please chime in!)
VeeDubTdi and storx, thanks for the graph comments. Tyrel developed the graph and we should all thank VW for making the ECM react fast enough to vary the PWM signals to maintain the required flow and pressure rates.
All the best,
Good question N2ADTDI,2Micron - does the fuel metering valve work the same way on both pumps?
This was one of the earliest discoveries in the experiment. Yes, they function the same.
These solenoids recieve 12 volts, then they are negatively triggered, via PWM signal from ECM. Operating frequency is around 180Hz, with the duty cycle ranging from 5% to 40%.
De-energized = Low fuel volume into pump.
Energized = High fuel volume into pump.
.
The CP3 and CP4.1 pump's FMC valves are quite different in physical size. Fortunately, the coils have the same resistance.
.
TDIMiester - yes, you are correct. The graph simply shows the relationship between "specified" and "actual" pressure in the rail. VCDS sample rate is not nearly fast enough to measure the pressure wave fluctuations. PM me if you are interested in the "Full" VCDS data, in excel. (if any one knows how to post Excel here, please chime in!)
VeeDubTdi and storx, thanks for the graph comments. Tyrel developed the graph and we should all thank VW for making the ECM react fast enough to vary the PWM signals to maintain the required flow and pressure rates.
All the best,