At 03:14 PM 4/13/2010, pdooley wrote: >Could we assume the injector drivers are not getting enough current to open >the injector solenoids due to faulty solder joints limiting current flow? >Noid light only shows the signal, not the strength, as Mark pointed out. Another reason for driver-transistor failure is connecting or disconnecting the load while the ECU is powered. They warn you about this in the book and they're not fooling; and the fact that it didn't fail right then doesn't mean you got away with it. It can easily generate voltage spikes that will try to punch through the thin insulating layer inside the transistors, and the damage can accumulate until the Xistor fails in operation. However I think that would usually cause the transistor to fail short in some way (when they melt they tend to fail open). I'm pretty sure these transistors are field-effect transistors, but they're operated in what would be called open-collector mode with a junction transistor. That means that the power to the load is supplied externally, and the FETs switch the load on by opening a low-resistance path to ground; so if you'd punctured one the 'noid light should stay on continuously and the injectors would spray as long as there was pressure in the system and ECU powered. Yours, D |
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