Injector Voltage

[chaseincats]

43 minutes ago, Captain Obvious said:

OK, got it. So getting into the details about the voltage number measurements you got... I'm pretty sure you already know this, but they don't really make sense.

If you pull the all the injector connectors off, turn the key to ON, and measure across the two injector connections inside any of the connectors, I would expect to see a low voltage on all of them. But it's a little unpredictable because of the way the circuit works. One side of each connector should be connected to the battery (through the dropping resistor) and the other side of each connector should be floating pretty much as a no-connect.

However, there is a capacitive load on each of those floating sides that could provide some weird numbers if you don't know what you're looking at. You could charge or discharge that capacitor through your meter and the numbers could change as you're watching them.

So with all that in mind (and as mentioned above), it would probably be easiest to change the way you are taking your measurements and see what you get when you just measure from the injector contacts to a known good ground instead of measuring between the two contacts in the same shell.

I mean, there's info to be gleaned from what you already did, but without being there and seeing what type of meter you're using and watching the numbers for stability, it would be simpler just to re-do the measurements and reference everything to ground.

Sounds good.  He is getting the car back today and will clean the terminals on the dropping resistor just in case.  I'll let you know the results and take measurements next time I'm over.

[chaseincats]

We ended up cleaning the terminals on the dropping resistor and now the car idles really well.  After the fact, we measured all of the injectors through the ECU connector and they all ready ~10.5v.  I checked the dropping resistor power wires, the main power wire was battery voltage and the one on the top left was around 10.5v (same as the injectors).

Not sure if that's how its supposed to be, but now it's idling well.