Injector Driver??
- Thread starter MKIII87Turbo
- Start date
MKIII87Turbo said:
Right terminology for what? There are such things as injector drivers but you won't find that term in the TSRM. It's the technical name used for the MOSFETS internal to the ECU that sink current to the injectors but I've a feeling that isn't what you're refering to. Elaborate and maybe we can help you out.
*edit* Before any other EEs out there jump on me I don't know for sure the drivers are MOSFETS. They could be Darlingtons. Then again, I guess it's not all that important anyway
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I have to assume the person was talking about the EFI Resistor, but that checks out, even put one from a working car. The next question is what is my problem, I don't get a signal to the injector clips.
MKIII87Turbo said:
Yeah, pretty easy to test the resistor pack. The Supra uses grouped injection in that pairs of injectors are turned on together. If you look at the wiring diagram you'll see how pairs are wired in parallel. Half the amount of fuel required is injected twice during each rotation of the crank.
Like most circuits, the injectors have a power side and a control side. Power wise, all the injectors are fed +12 vdc directly from the ignition switch and 30 amp fusible link AM2. The ecu grounds them using the transistors I mentioned. This is what I mean by the injectors being current sunk. When you switch power it's called sourcing, when you switch ground it's called sinking.
So power wise the injector circuit is pretty easy. Control wise it's a different ball of wax. Just when those transistors in the ecu turn on and for how long is dependent on many things and is more complicated than I want to go into just yet.
Basically, you need to look over the power side first and then go from there. AM2 ok? 12 volts at the resistor connector? Any codes? Are you getting spark? The ecu uses input from the CPS in several ways to calculate injection so spark is a sign the CPS is working. Check that stuff out first.
I'd say blown EFI fuse or bad CPS connection are the two likely suspects. If it was the EFI fuse, check back by the EGR valve and see if the harness has laid down on the tube.
No. On some systems, not this one or any Toyota that I know of, the control unit operates the injectors. Toyota has the control unit switch the ground side instead.
how is the ground?
reason is taht failing all six injectors... the only thing that comes to mind is either a fubared ecu or terrible grounds.
reason is taht failing all six injectors... the only thing that comes to mind is either a fubared ecu or terrible grounds.