[Datatek]

1 sensor drives the gauge
1 sensor tells the ECU the temp
1 sensor is for the HEVAC system to tell it the coolant temp

If the sensor to the ECU if duff you will get difficult starting and odd running

Sorry not so. The sensor at the back of the head nearest the bulkhead is a thermal switch that brings on the aircon fans in an engine overheat situation, it's not fitted pre 99.
The water temperature sensor for the HEVAC is on the pipe to the heater matrix.

 

[Datatek]

A bit more info on this.
The symptoms have developed a bit.
When cold, the car starts up and idles around 900 rpm, pressing the brake pedal causes the rpm to drop to about 700 rpm the idle becomes very lumpy with the engine shaking. Releasing the pedal it stays lumpy.

If the brake pedal is not touched the idle is fine.

The car stays stuttery when driving around 2000 rpm, and slowing down to a stop the lumpy idle takes over and it stutters to a stop. Only when really warm the symptons more or less dissapear, after 40 mins driving.

I have resistance tested the lift injector (king injector) and got 100 Ohms, so that seems fine.
I connected an air line up to the map sensor, the resistance does change but only by about 3 Ohms, 3500 to 3503 Ohms. Seems like a very narrow range.
I have a pressure gauge on the turbo, it reads steady doesn't seem to be a leak.
I remade and checked all the main body earths.
Disconnected the alternator, to see if this was dragging the engine,( it wasn't)
Cleaned and tested egr valve. Ok.

The only thing I did find, was nestling among the glow plugs seem to be 3 water temp sensors, they are not mentioned in the manual.
Why are there 3 and what do they do?

Interestlingly 2 of them read between 200 and 900 Ohms. the one in the picture read open circuit, could this be the problem.

I can't understand why the revs drop when the brake pedal is pressed, it's not an engine vacuum driven system.

So I'm still stumped, I'll replace that water sensor. Could a temp sensor cause all this trouble?


sensor by Sovereign125a, on Flickr

You really need to look at this on diagnostics

 

[Saint.V8]

Sorry not so. The sensor at the back of the head nearest the bulkhead is a thermal switch that brings on the aircon fans in an engine overheat situation, it's not fitted pre 99.
The water temperature sensor for the HEVAC is on the pipe to the heater matrix.

Opps...my bad...I knew what it was, just lost my head!

 

[sovereign]

Thanks Datatek and Saint, looks like there's no point in changing that sensor so, as it's not involved in the day to day running of the engine.
The fact it is a switch for fans rathar than an analoge sender explains its open circuit reading.

I would love to get it on a diagnostic if I knew a friendly LR garage that would let me take a look.
I believe a lot of garages don't know how to interepret the data, or how the systems really work.
Reading a lot of threads on different forums, it would appear thousands of pounds are being spent changing perfectly serviceable parts.

There is a LR dealer near where I work, I'll see if they will have a look for me.

 

[sovereign]

quick question, not ready to give up yet.
If it was a petrol car I would be pulling HT leads to isolate a faulty cylinder.

With the engine running, and vibrating as per the fault. Would slackening off a Diesel injector union, be a good idea,to test if fuel is present, or does it blow out all over the place. The engine is really running like it's down a cylinder. Perfect once up to temp though.

Or loosen the union then start the engine?

 

[speedyyellow]

Don't crucify my for this, but on Wheeler Dealers (I know, I know) they took an injector off and stuck it in a plastic bottle, then started the engine to test if there was fuel flow. No idea how applicable that information is though!

 

[Datatek]

quick question, not ready to give up yet.
If it was a petrol car I would be pulling HT leads to isolate a faulty cylinder.

With the engine running, and vibrating as per the fault. Would slackening off a Diesel injector union, be a good idea,to test if fuel is present, or does it blow out all over the place. The engine is really running like it's down a cylinder. Perfect once up to temp though.

Or loosen the union then start the engine?

You can slacken the unions one by one with the engine running but be very careful, the fuel is at high pressure and can penetrate the skin causing serious problems. Wear rubber gloves.

 

[Grit Valve]

Cracking open injector pipes is not going to tell you that you got a faulty injector just that the injectors are being fed with fuel.

Ps I think wammers was right
In the first place revs too low you can always put your foot on the brake increase the revs just a little and put it in gear if better reset the revs with a nano.

 

[Bix]

Cracking open injector pipes is not going to tell you that you got a faulty injector just that the injectors are being fed with fuel.

Actually it will. If you starve a cylinder of fuel that is normally fuelled the engine will run lumpier. If the cylinder is already starved of fuel it will make no change to how the engine runs. It isn't exact science, but gives you a good starting point.

 

[Grit Valve]

Actually it will. If you starve a cylinder of fuel that is normally fuelled the engine will run lumpier. If the cylinder is already starved of fuel it will make no change to how the engine runs. It isn't exact science, but gives you a good starting point.

Only if the injector is blocked unlikely they usually drip instead of spray if one was blocked I'm sure the others would with contaminated fuel ect don't you think if one was totally blocked it would run like a pig .

 

[Bix]

Only if the injector is blocked unlikely they usually drip instead of spray if one was blocked I'm sure the others would with contaminated fuel ect

True, it does seem a bit clutching at straws. Unless all of the injectors are slightly gunged up and need a good flush.

 

[Grit Valve]

True, it does seem a bit clutching at straws. Unless all of the injectors are slightly gunged up and need a good flush.

I've always known auto's if not enought revs when put in gear struggle and die , the most simplest test would of been left foot on brake right on peddle increase just a bit put in gear , not in front of a wall or shop window

 

[Bix]

I've always known auto's if not enought revs when put in gear struggle and die , the most simplest test would of been left foot in brake right on peddle increase just a bit put in gear , not in front of a wall or shop window

Original tests showed the with no foot on the brake it engaged fine. Personally 4 axle stands are a safer option.

 

[Datatek]

Only if the injector is blocked unlikely they usually drip instead of spray if one was blocked I'm sure the others would with contaminated fuel ect don't you think if one was totally blocked it would run like a pig .

Actually, like pulling plug leads on a petrol it can work quite well.
If one injector is not spraying well causing poor combustion, cracking that union will have less effect than cracking the union on a good cylinder.

 

[Grit Valve]

Original tests showed the with no foot on the brake it engaged fine. Personally 4 axle stands are a safer option.

Nothing holding it back with foot on brake if it was just enough, axel stand just a tickle on the revs an assistant would do driver on foot brake person holding revs at say 800

 

[Grit Valve]

Actually, like pulling plug leads on a petrol it can work quite well.
If one injector is not spraying well causing poor combustion, cracking that union will have less effect than cracking the union on a good cylinder.

Yes I understand , you would know if you had an injector not working well I would by the sound of it ! As said just finding what one , I think this is a revs issue I might be wrong well see hopefully .

 

[sovereign]

Thanks for those replies I would try cracking the unions, except for something happened today.
Driving along, I heard a beep looked at the message display ABS FAULT and the "TC" light is up.

I pulled over switched off, and headed off again, after a while Beep "TC" light up again.
When I got home just before the engine was shut off I saw 3 lights up on dash. The TC , traction control, and brake warning light. Just the usual Rangie spurious lights I thought.

About an hour later reversing out of the driveway, the brake pedal almost went to the floor, and a lot of effort was required to bring the car to a stop.
Nearly ended up in a neighbour garden. So I disconnected the connector to the brake pump, 12 Volts is present but no pumping. The black relay is also energised. I removed the back off the pump and applied 12 Volts directly to the solder terminals, no go. So the pump has had it.

So now I have to find a cheap pump, I am wondering if this is just a new problem or is this part of the original problem. Sorry, I'm sure this thread is just ****ing people off, but all the replies do help. Possibly the pump was running all the time.

My Rangie is lucky I 'effin' love it.

 

[Grit Valve]

Probably a new problem , although if it was shorting could of put a strain on the tickover ,

Try our sponsor at the top of the page if no luck , let me know and I will pm you a place I know .

 

[Datatek]

Replace the relay as well as the pump. A sticking relay is the usual cause of pump failure.
It's just a new fault, I'm sure it would not affect your other problem as the EDC should compensate for the additional alternator load required to drive the pump.

 

[Saint.V8]

+1 to both!