First, I'd like to link this new thread to an older one that I guess should wither on the vine rather than be resurrected: https://landroverforums.com/forum/di...o-pulse-48579/

I have +12V at the injector when ignition in PII, but no pulse. From what I gather reading the RAVE ETM, -12V is 'pulsed' from the ECM to the injectors. I have done a noid light test to confirm that I have no pulse.

I am concerned that some level of the anti-theft system is blocking pulse to the injectors (I have spark and fuel pressure at the rail). I have this concern b/c the PO said it would start, but would die and not start again for a period of time afterward. The PO also said he had to jump start the vehicle due to a dead battery. From what I read, a dead battery or a removed battery cable with the hood (bonnet) open and hood switch not pressed can trigger some of the anti-theft circuitry. Would the anti-theft system ever leave the coil (again, i have spark) and the fuel pump energized but cut pulse to the injectors?

If the anti-theft mechanism is NOT responsible for the absence of -12V pulse at the injectors, what else might it be? Bad ground at the ECM? Bad grounds elsewhere? If so, which ground points are the most likely culprits to a bad ground condition? Bad ECM? If a bad ECM, would I need to have a replacement ECM reprogrammed to my VIN? Would I need a new 10AS, too (whatever that is)? What other electronics might I need to 'mate' with the replacement ECM?

All replies welcome - even "dude, you're an idiot" - at least I'll know people read my post.

 

I just learned about this. The ECM can be mated to the 10AS, which is the green plastic box in the passenger footwell that houses the alarm electronics.

Apparently they can be inseperable, but not always.

That's all I can contribute.

Oh, and "dude you're an idiot"...

 

I may get flamed for this, or some might even say "dude, you're an idiot" ....but I think a trip to the dealer who has a Testbook (official LR computer diagnostic tool) might be the path of least resistance. But a thorough conversation about possible outcomes and fees should be had in advance.

 

I'm an idiot. Hahahahaha!

I'll go to the dealer if I don't get this fixed before the snow melts here in Michigan, which is usually about mid-August.

Anybody with any other thoughts (like, might this be related to the anti-theft system?) please feel free to offer them up and call me an idiot.

 

There's only two seasons here, winter and not winter.

Have you checked every fuse?

 

I will re-check every fuse today. I'm working this project 'remote', that is to say, telling the other bloke what to look at next and he's checked the fuses, but I intend to start there today when I look at it in person.

Thanks for the feedback.

Keep the cards and letters coming.

 

My 1996 had issues with the green box sometimes. Mainly because it's tabs were broken off and it wouldn't stay mounted. It would flop around and then not start again. If I recall correctly, when it thought it was being stolen, it wouldn't even crank.

 

I didn't mention in my first post, but the engine will crank. It will actually run if I manually provide fuel into the plenum.

 

Read this in your spare time; The Definitive Alarm Spider Post - Land Rover Technical Archive - LR4x4 - The Land Rover Forum

 

Thanks Scout! That is a great writeup and I came across it earlier this week and read it. It seems to indicate that if activated, the anti-theft mechanism will cut power to the fuel pump and to the coil(s) rather than to the injectors.

I will re-read it and will also likely build the spider by-pass like the images with the yellow wires soldered to the connector block internally (post #3).

I'll continue to keep this thread updated until I find the problem. But in the meantime, please share any thoughts you have on my situation.