Normal ground resistances

[KnifeySpoony]

So I'm still trying to diagnose my part throttle misfire. I went and checked continuity on various things - coils, injectors, sensors, etc. Using the continuity check on my multimeter everything was ok with a BEEP. However I realized that it will beep with anything less than 120ohms. So looking at the actual resistance, I noticed that all of the coil (and I think injector) grounds are consistent at 44ohms. Other various grounds were sub 1ohm. Is this normal?

Edited August 12, 2023 by KnifeySpoony

[KnifeySpoony]

FYI resistance was check with ECU plugged in, kill switch on, but car's ignition/power off. 

[MV8]

Injectors and coils should have full B+ with the key in RUN and START. The "difference of potential" associated with applying B+ and a ground across something is controlled by the ecu and crank trigger but not an actual consistent "ground" normally checked with a dvm.

[KnifeySpoony]

Sorry, can you translate for an electronics idiot - I don't know what B+ refers to.  I assume you're saying the key needs to be in the on position to test for ground on ignition and coils?

[MV8]

B+ = battery positive. Don't test for ground on coils unless you are checking for a wire shorted to ground by unplugging the ecu and the coils.

I guess you are trying to do something while waiting for the injector noid kit to be delivered? How about inspecting the #4 injector inlet screen, check the B+ key-on to #4 with the dc volts setting, and the resistance across each injectors terminals to compare them to each other?

[KnifeySpoony]

I actually have a spare ECU sitting here that I am going to flash and then swap in to see if it's an ECU issue. Hope to do that this weekend. Next step will be injector troubleshooting. Thinking about it, I can't help but think this issue is some sequelae or somehow related to a prior high RPM high load misfire I had previously, that was caused by a broken coil loom wire to coil on #4. Relatively soon after fixing that, this new misfire appeared. Perhaps that first problem caused some type of damage to the injector or ECU coil driver? Seems like an odd coincidence otherwise.