Thread: 99 V8 Disco 1 - So over it. Won't run.

Have you tested the pick up coil?
Test it once you have lost spark. remove amplifier and and connect multimeter to it, it should be 2k to 5k ohms.

Disconnecting the condensor

Huh?
You probably mean the capacitor to reduce radio interference.

You have done all the obvious things so probably should check on the pickup coil as the other poster said. You are down to very unusual problems.
Do you have a timing Light? I fear you may have done something that has caused a second problem eg pulled on the distributor shaft and lost the weights.
What was the original problem that caused you to do all this?
Did it just stop one day or was there a period when it went but badly?
If you have stated this in another post, just give the reference and I will look at it.
Regard sPhilip A

Hi Woko thanks so much for the reply.
As fellow landrover owners I'm sure you know how demoralising this can be - and it's easy to forget some things I checked

The pickup coil in the distributor has around 3.5 k resistance raising to around 3.9 when it's hot (as I would expect) - also the distributor and auto advance units are sound.

I'm starting to suspect the voltage to the coil as when it starts it seems fine then just stops like someone removed the power. All the dash lights etc stay on though so it's not a global problem - ie its localised to the ignition.

Please keep the ideas coming as I am absolutely stumped here

Thanks again
Pauly

Hi Phillip,

Yes they are sometimes called condensers as well because they condense or hold dc voltage while letting certain frequencies of ac through. Hence the suppressing characteristics with interference.

Anyway - yes I do have a timing light - when its running, the timing is perfect - advancing correctly etc. when its not running there is no spark, and I can therefore see that as the timing light doesn't flash when I'm cranking it over. If I leave it for an hour, I can then see the timing light flash when I crank it over, and it starts ok.

The original problem was that it just stopped on the highway, displaying classic fuel pump symptoms which was why I replaced the fuel system first!

It was running beautifully just before it stopped.

Thanks for the reply
Pauly

Originally Posted by PhilipA

Huh?
You probably mean the capacitor to reduce radio interferences

You have done all the obvious things so probably should check on the pickup coil as the other poster said. You are down to very unusual problems.
Do you have a timing Light? I fear you may have done something that has caused a second problem eg pulled on the distributor shaft and lost the weights.
What was the original problem that caused you to do all this?
Did it just stop one day or was there a period when it went but badly?
If you have stated this in another post, just give the reference and I will look at it.
Regard sPhilip A

Well really there are not many components in the ignition system , that will cause problems.
It has to be the coil, the distributor or the amplifier or the supply of power to any or those or an earth.
The fact that it is intermittent and stops after a while suggests to me a poor earth or positive connection or a dud coil.
AFAIR there is an ignition relay which you should change for a known good one as poor contacts in a relay could increase resistance . Check the continuity of wiring from the relay to the coil.

You say that you fed 12V to the coil and it still had no spark. This suggests that the new coil may be crook as you should certainly have spark then unless the amp or pickup is crook.

I must say I have never been in this position, but if i were you I would do some component swapping and maybe replace all the wring from coil to amp etc just to eliminate those components.
Regards Philip A

Hi Phillip,

Thanks again for the quick reply.

I agree - I think it's the supply of power as I've run a separate earth as well as checked out and cleaned up the existing earth strap connections.

So.... What are the wires going to the coil etc?
I have a blue and a red wire - they come from the dizzy and go to the module. I also have two wires coming from the module to the coil... So those 4 are obvious in regard to their origin and destination.

There are two other wires going to the coil though that I'm not sure of. One is white with a black stripe, and the other I cannot remember ( not with the vehicle right now) . These two wires come from the loom and I think one is just battery positive switched by the ignition switch however I'm not 100% sure.

Is there a circuit diagram of how these fit in?

Thanks again for the replies and any advice.

Pauly

Originally Posted by PhilipA

Well really there are not many components in the ignition system , that will cause problems.
It has to be the coil, the distributor or the amplifier or the supply of power to any or those or an earth.
The fact that it is intermittent and stops after a while suggests to me a poor earth or positive connection or a dud coil.
AFAIR there is an ignition relay which you should change for a known good one as poor contacts in a relay could increase resistance . Check the continuity of wiring from the relay to the coil.

You say that you fed 12V to the coil and it still had no spark. This suggests that the new coil may be crook as you should certainly have spark then unless the amp or pickup is crook.

I must say I have never been in this position, but if i were you I would do some component swapping and maybe replace all the wring from coil to amp etc just to eliminate those components.
Regards Philip A

You say that it just stopped on the highway one day.

Does it start normally and drive ok for a while then just die and then start again after it cools down.

I notice that a new coolant temp sensor is not on your have done list.

It may be worth a shot, I had similar problems with mine and ended up with a list similar to yours and it ended up being a $30 part.

What was happening was the faulty sensor was fluctuating between 40 & 90 deg so as you were driving it would think the engine was either hot or cold and give it either to much or to little fuel and I would end up stopped on the side of the road until it decided it would start again, until the next time.

Originally Posted by pauly

Hi Phillip,

Thanks again for the quick reply.

I agree - I think it's the supply of power as I've run a separate earth as well as checked out and cleaned up the existing earth strap connections.

So.... What are the wires going to the coil etc?
I have a blue and a red wire - they come from the dizzy and go to the module. I also have two wires coming from the module to the coil... So those 4 are obvious in regard to their origin and destination.

There are two other wires going to the coil though that I'm not sure of. One is white with a black stripe, and the other I cannot remember ( not with the vehicle right now) . These two wires come from the loom and I think one is just battery positive switched by the ignition switch however I'm not 100% sure.

Is there a circuit diagram of how these fit in?

Thanks again for the replies and any advice.

Pauly

The +12V feed from the loom to your coil and then the module should be plain white. The white/black stripe wire goes to the ECU and is the rotation signal from the ignition coil to the ECU. There is a resistor bound up near the coil and the wire changes colour after the resistor to white/blue stripe. If this wire is faulty you get no petrol injected, but you will still have spark. Of course the white/black stripe wire from the module to the coil is the switching wire, that allows the module to fire the coil.

You can test the 12V wire by wiring a test light to the coil +ve terminal and mounting it so you can monitor it while driving. If it goes out when the engine stops then your ignition feed is faulty.

The red and blue wires to the distributor pickup are the ones you test with a multimeter for the kind of resistance mentioned below.

In any case your most common problem is loose terminals. Any female terminal should be gently squeezed with flat pliers so that when you push it back on it cuts new contact stripes in the oxide layer on the terminals. All push on terminals should take noticeable force to remove. And they should be as clean as possible.