Techno Duck

A little confused about testing the injector harness. Do i need to have all 4 injector connectors disconnected for this test or should i remove and test one at a time?

I tested with all 4 disconnected and got 12v on one pin and 10.3v on the other indicating i may have a problem (same results across all 4 connectors). When i remove one connector at a time and test, i get 12v on both pins.

MM951

FWIW, I tested mine with a noid light disconnecting one at a time....Got sick of finding more cracks in the injector wiring and bought the LR harness. (actually, I bought all of them ) It's "only" $150 IRRC and now I longer have any issues or worry

Techno Duck

Planning on replacing it when I pull the intake next month. But I've got another week off now (boats underway) and want to do an auto-x this weekend. Hoping this injector harness could be related to my #2 and #3 cylinders running lean.

mikeyoman

No problems, at least I hope not 'cause with all injectors disconnected I also get 12v & 10.5v. The 10.5 v is coming from the DME circuits.
When at least one injector is still connected you will see the 12v supply feeding through that connected injector to the other pin (that normally connects to ground via the DME switching transistor)
That's if you are measuring the pins to ground, as opposed to measuring across the injector plug.
then you'll measure 0v or 1.5v depending on wether you have disconnected all the injectors or not.

Techno Duck

Mike, thanks for the confirmation on that. And i was measuring straight to ground (negative terminal).