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I am testing the voltage from the harness to the injectors. Does anyone know what voltage I should be getting during the injector clatter? My test light flickers, so I know I am getting electricity to the injectors.
I don’t know it but I think the FICM makes 48v to drive the injector solenoids. The logic side doesn’t need that kind of power. I would expect to see 48v at the connector during normal operation, I guess it might be lower on a buzz test.
My FICM Main power shows 48v. I am just wondering if the FICM isn't kicking out enough power to each injector and that's why I am getting a no start. My injector clatter is weak and the truck never had a problem starting until all of a sudden.
I was addressing the question of what the voltage might be at the injector connector. The power is pulsed very quickly sort of like the signal from a set of points in an old skool distributor. A multimeter, even a modern digital one, may have trouble reading the peaks so it’s likely the reading would wobble some and may be a bit lower than the actual peak to peak voltage that is present. I think to really nail it you would need an oscilloscope.
You are probably right. I am just trying to find something obvious, so I don't waste more money I did put a multimeter on the injector connector. The highest it showed precycle was 6 volts and during cranking 5 volts. Do you think this is my problem? or is it 48 volts total with 6 volts going to each injector? If each injector gets the full 48 volts then would you lean FICM. I did check multiple injectors with the same results.