Hmmm, ecu never turns off spark, they do that to make sure flooding is not possible and no explosions. So if you don't have spark, then either the wiring is bad (no pulse tp coils), the ECU is bad (no pulse to coils), or the coils are bad (no spark).

 

Fuses, relays, and key switch are used to provide battery voltage to the coil packs. Maybe start at the coil packs to check for battery voltage with key on. If voltage is there on the power wire, then problem is with the ground signal circuit that comes from the ECM. If no battery voltage, then use wiring diagram to work back toward the fuse box. Trouble shoot where voltage or ground should be, using the wiring diagrams as a road map.

To answer the question about where to put MM leads for injector check: Red lead to power wire, black lead to engine ground = batt volts whenever key on. Red to power wire, black to signal wire = mostly zero with short pulses towards batt volts. Red to signal wire, black to ground = mostly batt volts with short pulses towards zero. By the way, coil pack low voltage circuits can be checked in similar fashion, almost identical check, so determine which is the power wire and which is the signal wire, per coil.

 

OK so two follow up questions…

@Extinct should I remove all the plugs since I’ve presumably been firing gas into those chambers every time I attempt a crank? To let the gas evaporate? Would hate to fix the spark issue and have something explosive happen.

@JohnZo I *did* replace the key switch this last winter (https://landroverforums.com/forum/di...ts-not-124901/) but doubtful anything about that would lead to this issue since I’ve been running great since that repair? You mentioned the switch being part of the ignition sequence and was reminded to offer that info up.

 

1) Yes, you need to know if there is power, 12 volts, going to them and through them, just visually checking them...only tells you they are good to complete circuit. But, a good fuse...needs power from a source. Which would be supplied by engine compartment mega fuse. Corrosion in the fuse box or fuse spades can cause issues, too. Just because it has 12 volts across fuse...doesn't mean it's supplying enough amperage if corrosion enhances resistance enough.

2) Okay, so relay was firmly in place, good, you even swapped it out, good. Now, we need to know if it's getting power and ground signals.

3) Do you have the Electrical diagram manual downloaded?

Also, another quick check...see if you have power at coil pack plugs with key on. Since this issue started gradually, maybe coil packs failed. Both at once, yes, unusual...but not unheard of.

Eventually, you may be verifying ECM condition...so, the Electrical diagram manual is paramount. I've got it on my old tablet...l'll see if l can find it.

 

I have it yep, I’ll get investigating!

And agreed, especially since the coil packs are new, AND I swapped them out with another spare set, I’d be shocked if they were the culprit.

 

This thread is turning into one of those, situations. My guess is:

1) Throttle Position Sensor? That's a cheap and quick easy fix.
2) PCV Purge Valve? This normally throws a code first.

Also, if your going to replace the coil packs, you should always install the coil pack relocation kit.

Other than that, I'm guessing an electrical problem.

 

Reporting back. Getting 12v with ignition on at both coil packs.

 

Lots of very good advice in this thread. Using your multi meter for troubleshooting is right on. I don’t think I’d be quite as confident that my newly installed parts were good. I’ve certainly installed new parts that were bad out of the box. I know they’re a pain to access, but swapping in your original coil packs might be a step to take.

 

For sure, very thankful for the knowledge dump by everyone.

I ended up ordering new Bosch packs. I’d love do swap in my old ones but they were causing misfires this winter, hence the replacements. Hoping this solves it, but also so frustrated if it does since it kind of continues to prove this new reality of not being able to rely on new parts like we used to.

They’ll be here tomorrow.

 

Good to see battery voltage at the coils. That means fuses, wires, relays, and key switch are all good on the 12V side. The signal wires should pulse to ground while cranking/running. Maybe test using low ohm scale, red lead at connector, black to engine ground.

Also worth testing coil ohms. Low ohms on LV terminals (center to sides), high ohms on HV terminals (center to output terminal). I am not sure the specs, but the LV should all be nearly equal (1 ohm ballpark), and the HV should all be nearly equal (13k ohm ballpark). There are some solid state diodes involved in the coil packs, so might need to swap red and black MM leads to get proper ohm values. If applied polarity is reversed on a diode, the meter will show open circuit or very high ohms.