Discovery 1 3.5 V8 non starting - Immobiliser?

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JDZ2

JDZ2

Member
Posts
82
Location
Hersham, Surrey.
She started last week no problem but now just turns & turns with no attempt to fire up.
I suspect it may be this immobiliser I've been reading about.
So firstly, my Disco is a Feb 1993, has CATS alarm stickers in the window. It has a single button remote control with a red light on.
Does my Disco have an immobiliser? Where is it likely to be located?
Should the remote control operate the central locking as well as activate any alarm?...because it isn't!
If the red light comes on when I press the button, does that mean the battery in the remote is good enough?
 
JDZ2 said:
A '93 model with one button fob, I have now read, doesn't have a spider that needs bypassing, right?
Click to expand...

Correct it doesn’t. Your disco, is a1993MY it would be fitted would has an ‘active’ security system as standard meaning its set and unset either with the key or the optional central locking fob, and not ‘passive’ as the latter models, the immobiliser is part of the security ECU.
So the engine cranks, are you getting fuel to the plugs, do u have 12v at the coil + when the ignition switch is in position 2, do u have a spark at the end of the king lead/spark plugs. ?

CATS = Computer Anti - Theft System refers to the radio/cassette player, basically the four digit code.
 
Last edited:
discool said:
Correct it doesn’t. Your disco, is a1993MY it would be fitted would has an ‘active’ security system as standard meaning its set and unset either with the key or the optional central locking fob, and not ‘passive’ as the latter models, the immobiliser is part of the security ECU.
So the engine cranks, are you getting fuel to the plugs, do u have 12v at the coil + when the ignition switch is in position 2, do u have a spark at the end of the king lead/spark plugs. ?

CATS = Computer Anti - Theft System refers to the radio/cassette player, basically the four digit code.
Click to expand...
Hi Discool, thanks for the reply. I can hear the fuel pump prime itself but don't know if there is fuel to the plugs. How do I check that? When I removed the plugs they were quite wet & so I took that as meaning that fuel was there, I could smell the petrol. No, I didn't have 12v at the coil. I read one of your previous posts about fixing the spider thing, but what you did was to run a cable from the fuse box. So, I did the same, put the meter on & had a reading of 12.4 approx. But it didn't make any difference. So, now what? Starter motor?
 
Sorry, so I don't have the spider thing but I do have an immobiliser? The central locking fob doesn't seem to do anything. The red light on the fob flashes & I hear a kind of double click coming from somewhere in the cabin but none of the locks do anything. The driver's door lock is broken so I can't lock it with a key. If I remember correctly, I think it needs one of those plastic shims..
 
My last post isn't completely accurate - the fob does seem to operate the alarm. Sometimes when I put the key in the ignition & turn it on or sometimes when I open a door, the alarm will go off & then I use the fob to silence the noise.
 
I’ll place my comments to you three posts all together.

1. Wet plugs is a very good indicator that fuel is getting into the combustion chamber.

2. You need the 12v at the coil, which is isolated via the immobiliser, a temp feed from battery+ to coil+ will do.

Check for a spark, the ignition amplifier that screw to the side of the distributor can go faulty, so no spark.
3. What do u believe is wrong with the starter? when u state “now just turns & turns” I assume u mean the engine cranks.

4. Drivers door lock doesn’t help, as via a micro switch the lock barrel sets/unsets the alarm immobiliser, the plastic cam has been known to break therefore not operating the switch, so the security system is still set when u unlock with a key, a working fob will/ should unset the system allowing the alarm/immobiliser to be turned off.

5. The central locking is controlled via separate relay from a signal from the ecu, that maybe the item thats clicking, look for a standalone relay under the dash somewhere near the ecu, its black, it may have been changed, but for pics of the item... google.

Thats about it I think of the top of my head :)





Sent from my iPad on a train.
 
discool said:
I’ll place my comments to you three posts all together.

1. Wet plugs is a very good indicator that fuel is getting into the combustion chamber.

2. You need the 12v at the coil, which is isolated via the immobiliser, a temp feed from battery+ to coil+ will do.

Check for a spark, the ignition amplifier that screw to the side of the distributor can go faulty, so no spark.
3. What do u believe is wrong with the starter? when u state “now just turns & turns” I assume u mean the engine cranks.

4. Drivers door lock doesn’t help, as via a micro switch the lock barrel sets/unsets the alarm immobiliser, the plastic cam has been known to break therefore not operating the switch, so the security system is still set when u unlock with a key, a working fob will/ should unset the system allowing the alarm/immobiliser to be turned off.

5. The central locking is controlled via separate relay from a signal from the ecu, that maybe the item thats clicking, look for a standalone relay under the dash somewhere near the ecu, its black, it may have been changed, but for pics of the item... google.

Thats about it I think of the top of my head :)





Sent from my iPad on a train.
Click to expand...
Thanks for the time Discool.
No 1 & 2, is what I thought too.
In my experience, which is limited, what I mean is, the engine will turn over, crank, & will make some effort to try to start. In this case, there is no interruption, the battery is fully charged & the engine cranks & cranks but there is no splutter or cough, likes it's not catching. I'm sorry, I can't think of another way to describe it!
I checked for spark, on only one plug, & it was strong, clearly arcing.
No 3. The starter motor - I don't know if it has power - I'm thinking it may be bad because with my limited knowledge it seems like the next thing to try, when I don't know what else it can be.
No 4. The drivers door lock - I don't lock or unlock it because the key just spins in the whole, the lock doesn't operate with the key. It will lock pressing the button down on the inside.

I don't need to be able to lock the car, I certainly don't need central locking nor an alarm or remote key fobs. I would be happy to by pass / remove these things.
 
OK, some sleep but thinking about the Disco in the night too!
Let me refresh my thinking here.
So, when I turn the key the engine turns / cranks. It's the starter motor that turns the engine initially until the engine fires...right? So, there is nothing wrong with the starter motor.
Fuel, ignition, oxygen. I thought I had fuel because when I removed the plugs, they were wet & I could smell the petrol. I tested for a spark by taking out one plug & holding it against the block - there was a good spark. The coil had a virtually zero reading, so I ran a 12v feed from a relay in the car & then the coil read 12.4v.
How does the immobiliser do it's thing? It cuts off power to the coil or starter or fuel pump or all, right?
When I turn the key, I can hear the fuel pump prime itself. So, my conclusion is the immobiliser is not the issue! Could the fuel pump be working but the fuel is not getting to the engine?
 
I've got a tin of easy start, tried it, no difference. Taken a couple of plugs out, tried them on the engine block, both have good sparks. The plugs were wet, I can smell
the easy start, that high octane fuel. I've checked the wire terminals on the coil, improved one of them & now have 12.3 on the meter without needing to run another 12v feed...so that's good.
I'm reading the haynes manual, chapter 5b.2 ignition system testing, about the amplifier that is next to the coil & it says "coil negative terminal ( wire to amplifier module ). Is this correct because the wire from my amplifier goes to the positive side of the coil...which is right please?
 
Another day trying to get it started & failing! In my last post, I asked about the amplifier but I was confusing it with the noise suppressor :rolleyes:
Subsequently found the amplifier on the distributor which is a 35DLM8 type.
Had all the plugs out, they're all heavily wet but they all spark...individually at least.
So, if I have fuel & I have spark, then 2 out of 3 leaves air.
In this situation, I don't know what to do next. Any advice please?
Does any strength of spark mean there isn't an ignition problem? If I can have a spark & an ignition problem, what do I check, try next?
 
JDZ2 said:
Another day trying to get it started & failing! In my last post, I asked about the amplifier but I was confusing it with the noise suppressor :rolleyes:
Subsequently found the amplifier on the distributor which is a 35DLM8 type.
Had all the plugs out, they're all heavily wet but they all spark...individually at least.
So, if I have fuel & I have spark, then 2 out of 3 leaves air.
In this situation, I don't know what to do next. Any advice please?
Does any strength of spark mean there isn't an ignition problem? If I can have a spark & an ignition problem, what do I check, try next?
Click to expand...
Ok, have a look at these links below. As u have fuel and a spark means that u have power to the coil which basically signals the efi ecu which signals the fuel pump to run, a strong blue spark at the plug tip is good, thats all there is, and engine should at least cough. Of course the engine wont start if the plugs are soaked in petrol. :(
So its now time for looking at items that will give difficult starting, the easiest to start with is the Idle Control Valve thats shown in the 1st link and details its operation operation.


http://www.britishv8.org/articles/rover-14cux-efi.htm
https://www.actproducts.co.uk/2011/...n-system-–-installation-and-diagnostic-notes/
http://duud.ee/LR-manualid/Discovery_Workshop_Manual.pdf
 
Thanks for the message. So your hinting at the timing right? I will take a look at that too.
At the moment, I'm walking away from it for a couple of hours at least - it's doing my head in.
It just doesn't make sense to me. It was sat for about 6 months on the street. I went to move it but of course the battery was flat. I used jump leads & she started straight away.
My wife drove it onto the drive. I needed to move it the next morning because she had half blocked the drive & the Disco started first turn of the key.
Then the following day, she won't start! It feels to me like its associated with the central locking and/or the remote key fobs, something electronic is stopping it, rather than a timing or ignition type of problem. When she did start after the 6 months, the spare key was used because I couldn't find the main set. Likewise, the next day. But when she refused to start, I had found the main set of keys & it's possible, reasonable, that I pressed the remote control fob! The central locking isn't working when I use the fob, even though the red light comes on. I will get some new batteries. But could this be the reason for the problem? Or am I barking up the wrong tree completely & need to concentrate on the areas I've been advised to?
 
Discovery 1 MY97 V8 IGN.png
Discovery 1 MY97 V8 IGN WITHOUT IMM.png
Discovery 1 MY97 V8 IGNITION.png
 
JDZ2 said:
Thanks for the message. So your hinting at the timing right? I will take a look at that too.
At the moment, I'm walking away from it for a couple of hours at least - it's doing my head in.
It just doesn't make sense to me. It was sat for about 6 months on the street. I went to move it but of course the battery was flat. I used jump leads & she started straight away.
My wife drove it onto the drive. I needed to move it the next morning because she had half blocked the drive & the Disco started first turn of the key.
Then the following day, she won't start! It feels to me like its associated with the central locking and/or the remote key fobs, something electronic is stopping it, rather than a timing or ignition type of problem. When she did start after the 6 months, the spare key was used because I couldn't find the main set. Likewise, the next day. But when she refused to start, I had found the main set of keys & it's possible, reasonable, that I pressed the remote control fob! The central locking isn't working when I use the fob, even though the red light comes on. I will get some new batteries. But could this be the reason for the problem? Or am I barking up the wrong tree completely & need to concentrate on the areas I've been advised to?
Click to expand...
If it drove OK a couple of times, the timing is OK.
Problem lies elsewhere.
 
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