Landrover LR3: Come for the jokes but stay to help me fix it.

I am ready for the I told you go's but in reality this thing has been very trouble free for 100,000 km now which I did not expect for a wholesale lot bargain with 12 previous owners. It is a 2006 with the Ford sourced V6.

I am hoping someone can point me in a new direction as I am running out of ideas. This summer my wife had the LR3 one province away on a trip and reported that one day it did not start. But she did some more shopping and came back and it started. The next morning it would not start and I had it decked over to a shop where they started it many times over two days and it never failed to start. They reported no codes displayed.
It has happened a number of times since to me, but it will be fine for weeks or months before acting up again. The starter is fine and it turns over nicely until the starter times out. Battery is strong. I have replaced the crank sensor and the fuel pump, and I have a pressure gauge on the rail that always shows 60 psi. If I bleed off pressure it jumps up to 60 as soon as I hit the key so I am ruling out my new fuel pump and also the relay. I have a GAP tool and I have never seen a code. Last night after weeks of no trouble I jumped in in a hurry and nothing. I cranked until it timed out twice and then took my wife's car. Two hours later it fired right up. WTF. I would appreciate any suggestions as to where to go next.

Sorry, I've no direct useful experience, we've got an '08 LR3 with the same engine, 225k kms on it and haven't seen anything like that (hoping I haven't cursed us)

You can try asking on this Disco3 forum, very few with the V6 but if it's a general Disco3 issue they may be able to help:

http://www.disco3.co.uk/forum/

In reply to bearmtnmartin :

I hope we can help you find the problem

but I also just appreciate your humor and admitting to falling on your sword a bit with this. this is what i love about this place.

In reply to spacecadet :

I was after all pretty instrumental in jeering at the Freelander guy. 

In reply to bearmtnmartin :

i only followed the saga a little bit, but i figured you were involved.

Security thingie?

Experienced similar on my Mustang, was a bad wiring connection leading to the fuel pump.  Apply power, go through jiggling things with a meter on the other end?

Someone on another site pointed me to the immobilizer which seems like a long shot as it seems that it would not turn over if that was the issue, but it spins up fine. And I have ruled out fuel as the pump is new and I always have 60 psi at the rail. If I bleed the fuel pressure off and go to start it again it jumps back up to 60 instantly. 

I am going to see if I can find a thingie that I can put in line with a spark plug to confirm that when it does not start there is no spark. I am presuming there is no spark but I have not been able to confirm that yet. Then (help me here) I need to narrow it down to :

computer saying "no spark for you" If so, is it a security thing? 

sensor failing intermittently (I do have two new cam sensors yet to be installed but I don't think the symptoms point to them and anyway no codes ever) What else is there? Crank sensor already done. 

Mechanical issue with the key or ignition? I have tried jiggling pushing and pulling the key while turning it but I cannot recreate the issue. 

What else?

Immobilizer systems can show all sorts of failure modes. No crank, crank no start, start no run, etcetc. All depends on what segment of the chain failed (read the key, communicate with dme, etc).

I recommend you take it to a land rover deal so they can estimate $6k in repairs to get you to next Wednesday.

Toyota ECU's, at least of the 98 V8 vintage, will crank but no spark if the security code is not recognized.  Dunno about the Land Rover. 

Oh, and LR key fob thingies?  Who can program one of those besides the dealer?  Man, what a CF that is.  At least with Toyota there's this dead chicken dance you do involving chanting and door locks to get it to accept a new key.

I suspect this isn't it, but I don't see it explicitly above: you always get 60psi when testing it, but have to been able to test it while it was failing to start?

I would hope that if it's either security or something like crank or cam sensor, there would not only be no spark, but also no injector pulse.

Though, lacking both spark and injector, I guess you have to figure out whether it's security or a failure. "GAP tool" isn't familiar to me, but I'd hope to use on OBD tool of some kind to check for cranking RPM.

Do cam sensors throw a code if they don't have issues on normal running and just prevent start? Bad ground/power that causes dodgy cam signal but when running, system voltage comes up and masks the issue?

I have seen a bad ignition switch crank, but lose power to something else. Worth checking before you throw it in a river.

In reply to Ransom :

The GAp tool is the very necessary Land rover code reader. It will read all the ECU's in depth and do some programming. I used it to program a new FOB. 

I have a pressure guage where I can see it from the drivers seat. Twice now I have been able to see 60 psi while I crank and drain pressure from the guage. Then I cranked again and pressure jumped immediately but no start. I have tried to check for spark but the two tmes I pulled a plug it started right up. Usually when this happens (maybe 10 occurrences in total since last July) I turn the key a second time and it starts. But four times out of the 10 it has not started. Once I decided it had finally failed completely which would be great because I could dig into it. I tried it maybe 20 times while waiting for the deck truck over about 30 minutes. I tried one last time when the truck arrived and it started instantly. 

I will try the cam sensers because I have them, but from what I read they will throw a code when they go, and they don't usually go randomly. So I do not have high hopes. 

I suppose you presented a new possibility that I have not looked at. Fuel at the rail but injector says no to delivering it. How do I check that?

Samcrac just went through this with a LR. I forget which video he addresses it but here's the first one in the series:

https://www.youtube.com/watch?v=bA0NtAXiPy0

He's not much of a mechanic, but he's cheap.

*Edit: It's video 2 at around 11:00

https://www.youtube.com/watch?v=DHOcU5s38oo

Pull the trim panel off around the steering column, and check the electrical connector at the ignition switch.  That appears to still route actual electricity through the switch, so it may have melted a connector.  Another possibility is that it has an internal ignition switch problem, which you should be able to create/solve by pushing and pulling on the connector.

Security will certainly allow the crank, but disable the spark many times, because engineers are weird.  You should have some sort of security light mode change from normal if that's the issue.

There is a central junction box that is the terminator for every wire in the vehicle, too.  Wiggle stuff and see if it quits.  Unplug stuff and look for green.

Any crank or cam sensor failure will set a code pretty much immediately. 

In reply to Apis Mellifera :

I watched those videos. And that thing has so many issues and he is such a poor mechanic that I would not want to try anything that he has done.

bearmtnmartin said:

I suppose you presented a new possibility that I have not looked at. Fuel at the rail but injector says no to delivering it. How do I check that?

I don't know anything about LRs in particular, or about what sort of plugs they use, etc... But I believe the majority of cars are set up so the injector is supplied with 12V constantly, and the other terminal is grounded to pulse the injector. There are a number of articles floating around about using a voltmeter or light to test.

I'm pondering what this tells you that's different from spark, and  I think the primary thing is that if you have *neither*, then the computer says you shouldn't be starting (security or some other fault); if you have fuel but no spark, then there's something wrong with the spark system, because the system shouldn't be spraying fuel it doesn't intend to ignite. If you have spark but no fuel... you'd have to know something about LRs to say with any certainty that it's a problem with the injector system or possibly a "CPU says don't start" thing, though it seems odd to me that it would bother sparking if it's not supposed to run.

Does watching the pressure gauge drop tell us that the injectors are firing? I'd rather know definitively, but that would point to an issue with the CPU thinking it should be sparking but it isn't.

Bah! I found about seven typos on my way through that. Apologies if I missed any; apparently I'm typing really, really badly today.

On Honda products when the antenna for the key transponder fails, the vehicle will crank but not start.  And I understand that a Landrover is not a Honda.  But that is a similar chain of events.

I am looking into the immobilizer more. I have a second key that I will use for a while, and I will reflash the ECU which I can do with the scan tool. I must say though that when I open that menu it warns me if it does not work the vehicle may no longer run. Should I be concerned or forge ahead? I note when the immobilizer is mentioned as an issue in other conversations the red light is generally flashing when it shouldn't and mine has not been doing that. 

Flashing the ecu for a security code won't be your issue.  If it's lost the code, its lost the code.  You are far more likely to have a bad antenna or pickup at the switch.

Did you read my suggestions about the ignition switch?

In reply to Streetwiseguy :

Thank you yes. I am going to pull that apart this weekend.

Just to close off this conversation, I think I have nailed the problem. I found a bad wire in the connector for one of the cam sensors. I straightened it with a pick and have had no problems since. I am not calling it fixed yet as it has gone a month more than once without acting up, but it is going on 7 weeks now since the last event which is a record. The worrying thing though is that I do not generally see cam sensor issues that do not result in CEL's. But anyway, I am starting to trust that it will start when requested again. Too bad it cost me a new fuel pump and cam sensor that I did not need.