How slow 300tdi auto

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shocker the resistance in for no.4 injector is 90-110 ohms measured at the two pin connector or pin 5 and 12 at the ecu connector
I had to take mine to a dealer to get connected to the computer they quoted £65+vat for a diagnostic check and cleared various sensor faults but said ther was a problem with the injection timiming and lift valve timing and they estimated £300 to sort it . I left it with them to sort called today but hey were still waiting to get a better look at it so still not sure the problem will get sorted
 
Hi might be stating the obvious but have you checked air intake. Had a rover 620 power was great then. had timing belt changed and it ran a bag of. wouldn't accelerate took a life time to pass anything on motorway. took it back to garage they said it was ecu fooked. I told a friend who put it on diagnostic. to find airflow was well out. checked it all to find a rag inserted between air filter and manifold.After taking it out it ran like a new car well chuffed. Went back to the garage to take someones head off. But after big argument and not getting anywhere. I left it at that.
Now I'm glad I got my disco. everything is so easy to work on I don't need garages anymore.
on mine the inlet manifold was clogged up a bit with thick residue. cleaned it and it does run better. Not as big a problem as you got but its worth a look.
 
Nice one tony,thanks mate - that can go into my big book of test notes.

John,thanks for the input mate.....in my case though,no - cleaned the intercooler and pipes as a matter of course.The EGR is only disconnected,the vacuum hose that is,not blanked.I havent managed to get a gas spanner on the bolts as of yet,havent got around to making a new blank plate either.

I will put up anything that I do and the result.If we all do that we can get a pool of info that we can access at will to tame the EDC beast !

In the LR manual it mentions a fuel temp sensor....surely this would be a vital reading for startup?
 
the fuel temp sensor is located in the injection pump it can be checked at pins 13 and 35 of the ecu plug the resistance should be 2280-2720 ohms at 20 degrees C
 
Interesting , I have similar problem with mine. I have replaced the temp sensors for air and coolant as you have but using Hawkeye the fuel temp sensor still reads far to high at 50 °C when cold and stood overnight . Even with the new sensors for air and coolant it made no differeance and they read the same magnitude , slightly low . I have used Team Valley Land Rover before but not for my 300Tdi Disco Auto . They are cheaper than a Main Dealer and have the latest IDS diagnostic equipment . Did not know it did the older cars I thought it was for the more modern ones .
Where exactly is the ECU plug? Thanks Jonathan
 
the ecu plug is located in the drivers side foot well connected to the ecu ,if you remove the kick panel next to the throttle pedal and look up under the dash you can see it .
Was it it engine temp sensor in the middle of the cylinder head you replaced ? this is the one for ecu info
 
tony3001 said:
shocker the resistance in for no.4 injector is 90-110 ohms measured at the two pin connector or pin 5 and 12 at the ecu connector
I had to take mine to a dealer to get connected to the computer they quoted £65+vat for a diagnostic check and cleared various sensor faults but said ther was a problem with the injection timiming and lift valve timing and they estimated £300 to sort it . I left it with them to sort called today but hey were still waiting to get a better look at it so still not sure the problem will get sorted
Click to expand...
The problem you have is probably a slack timing belt or just a badly fitted timing belt.The purpose of the sensor is to tell the ecu the point of needle lift - ie,the start of injection.With this info the ecu can also use the crank sensor to adjust the pump timing to suit what it wants.In other words cloed loop timing.Obviously the pump can only adjust the timing within certain limits,if the point of injection occurs outside of these limits the mil lamp comes on and a fault is stored.
Testing the needle lift sensor with a multimeter is a bit of a waste of time,the only way to really test it is to see what its reading on Testbook or with a scope.At every speed except on overrun,(No injection - no fuel) it should read the same as the crank sensor.
 
My motor was experiencing intermittent misfires. These could happen at any time or throttle position. A lot of people have had problems with the throttle potentiometer that sound similar to this.
I had the codes read and they recorded "Engine speed" fault. Of course it didn't happen while I was at the garage, so we cleared them and waited for the problem to come back.
Nearly two weeks later, it started to fluff again then got really bad and lit the CEL on and off between 1100 -1900rpm. Starting went from good, to fingers crossed.
Same error reading, "Engine speed".
Garage looked up the reading and it is recorded as a result of the crank sensor and the injector sensor not working together properly. Doesn't tell you which one is at fault though.
I initially went to change the crank sensor but opted for the injector as this had been disturbed recently. Also the crank sensor is a real bitch to get at.
Changed the injector and my misfire and starting problems all went.

It was cheaper to buy a s/h injector and try it than buy the crank sensor anyway.
 
Davee said:
My motor was experiencing intermittent misfires. These could happen at any time or throttle position. A lot of people have had problems with the throttle potentiometer that sound similar to this.
I had the codes read and they recorded "Engine speed" fault. Of course it didn't happen while I was at the garage, so we cleared them and waited for the problem to come back.
Nearly two weeks later, it started to fluff again then got really bad and lit the CEL on and off between 1100 -1900rpm. Starting went from good, to fingers crossed.
Same error reading, "Engine speed".
Garage looked up the reading and it is recorded as a result of the crank sensor and the injector sensor not working together properly. Doesn't tell you which one is at fault though.
I initially went to change the crank sensor but opted for the injector as this had been disturbed recently. Also the crank sensor is a real bitch to get at.
Changed the injector and my misfire and starting problems all went.

It was cheaper to buy a s/h injector and try it than buy the crank sensor anyway.
Click to expand...
You want to find a different garage then.The fault code is meant as an indication - a rough guide,THEN you use live data displays to see what the ecu is seeing.On Testbook the engine speeds from crank and #4 injector are shown on the same page.They ought to be able to see which is at fault,even if it means "wiggle testing" all the sensor wires while its running.
This is what cheeses me off with some garages - like I said its a reliable system,with good diagnostic function - and VERY simple compared to some current systems.
 
8inaV, ...I didnt want to hear that! I have 3 300 engines in various states of assembly at present and was looking forward to NOT having another !

However,since the vehicle runs fine,absolutely fine,better than my others,once it is started I still think that the cold start timing is a fault.Im not saying you are wrong,just that the cold start is fecked ALSO.In the warm,it will start fine,the colder,the longer and harder (ooh-err!) it is.When extended cranking for start has been needed it displays the symptoms of excess fuel,to start with,mainly I suspect as it has had excess fuel pumped in whilst turning over.
If I was going to have the timing case off I would probably take the opportunity to have the pump serviced at the same time,which may be where the problem truly lies.
The only time I see a check engine light is when ALL the lights come on when the key is turned.
 
Tony3001, Yes the sensors I replaced were the one in the middle of the cyclinder head under the rubber mat and the one at the back of the inlet manifold between the engine and the bulkhead . Regards Jonathan
 
shocker said:
8inaV, ...I didnt want to hear that! I have 3 300 engines in various states of assembly at present and was looking forward to NOT having another !

However,since the vehicle runs fine,absolutely fine,better than my others,once it is started I still think that the cold start timing is a fault.Im not saying you are wrong,just that the cold start is fecked ALSO.In the warm,it will start fine,the colder,the longer and harder (ooh-err!) it is.When extended cranking for start has been needed it displays the symptoms of excess fuel,to start with,mainly I suspect as it has had excess fuel pumped in whilst turning over.
If I was going to have the timing case off I would probably take the opportunity to have the pump serviced at the same time,which may be where the problem truly lies.
The only time I see a check engine light is when ALL the lights come on when the key is turned.
Click to expand...
300TDI auto cold starting problems are almost always down to low cranking speeds or faulty glow plugs.(If the coolant temp sensor is giving the ecu a decent signal.)
When starting just about any diesel the more fuel the merrier in terms of actually firing it up - black smoke is the result of too much burnt fuel,white smoke is unburnt fuel.One of the few faultsof edc in these cars,(In my opinion only) is the low start quantity injected on cold starts - the manually governed pumps use a bigger quantity on start up as its dumb to engine temp/air temp etc.But its why they also give a healthy puff of black on firing up.
An extra earth lead between the battery and engine block is a very sensible mod as it will relieve the hanbrake cable of its current carrying duties.If it runs OK and the mil never comes on I doubt there is much wrong with the pump advance/solenoid unit.
 
This is a classic unburnt fuel smoker.I havent done the earth lead on this one,all my others have it for the reason you give.Got new battery (again) and glow plugs that I have had back out and tested.
I will try an extra earth...must have had a brain blockage on that one,since all my others have had it !
 
Fitted a bloody great earth cable from the aircon compressor boltholes to the battery today,as reminded by 8V.....increased turnover speed by 30%.......but still got the same bad starting problem !
The comedy continues.....PAS low pressure hose died today while I was out in the truck,dumped the ATF on the road as I was driving through a mass of coppers at an armed siege next door to my ex wifes place.Good timing,huh?
 
Well now you have a decent cranking speed,what else is missing ? If its injecting fuel that isnt burning then you have either low compression or the glow plugs are not being fed.
 
Thanks 8V.Heres the update.........

wasnt very cold last night and wasnt up on the moor so this may not be a true test.However,not having the capability to test over 10A,other than touching on the wire of an old seriesLR ammeter (which can have its moments) I went with trying a known working glow plug relay.The vehicle started on the second revolution,no smoke to speak of,no lights,ran fine. I dont think my father,the previous owner, had replaced that - I know I hadnt.The plugs are new and bench tested with a battery and seem good.

So.....could this be the cure? I will have to wait until the car has had time to get really cold,like not used for a couple of days and kept at home on the moor.THEN we shall see if has truly made a difference.

On a similar note....just how does the heater plug relay system work? I mean,how does it sense when to turn of? In the peugot XUD engines that I had a lot to do with in the past there was a box of circuitry that was twinned with the relay that gave a lot of trouble but the insides of the LR one are nothing like as complex.Does it sense a difference in resistance or impedence? Surely nothing like a temperature reading...???
 
shocker said:
Thanks 8V.Heres the update.........

wasnt very cold last night and wasnt up on the moor so this may not be a true test.However,not having the capability to test over 10A,other than touching on the wire of an old seriesLR ammeter (which can have its moments) I went with trying a known working glow plug relay.The vehicle started on the second revolution,no smoke to speak of,no lights,ran fine. I dont think my father,the previous owner, had replaced that - I know I hadnt.The plugs are new and bench tested with a battery and seem good.

So.....could this be the cure? I will have to wait until the car has had time to get really cold,like not used for a couple of days and kept at home on the moor.THEN we shall see if has truly made a difference.

On a similar note....just how does the heater plug relay system work? I mean,how does it sense when to turn of? In the peugot XUD engines that I had a lot to do with in the past there was a box of circuitry that was twinned with the relay that gave a lot of trouble but the insides of the LR one are nothing like as complex.Does it sense a difference in resistance or impedence? Surely nothing like a temperature reading...???
Click to expand...


From memory the glowplug circuit gets a temperature input and there is a timer also.

The plugs stay live for a short while after the engine has started, to aid the engine warm-up process.
 
shocker said:
That seems too obvious,thats why I doubted it !! But I dare say you are right
Click to expand...

This is what RAVE says:

"Glow plug operation is controlled by a timer unit, start relay and resistor. When the ignition is turned on the timer unit is energised, the glow plugs start to operate and a warning light on the dashboard illuminates, remaining illuminated until the glow plugs are automatically switched off.

The length of time the glow plugs will operate is dependant on under bonnet temperature, which is monitored by a sensor located in the timer unit.

Starting the engine results in the power supply to the glow plugs passing through the resistor, which reduces their operating temperature. The glow plugs are cut out either by the temperature sensor in the timer, or by a microswitch on the injection pump which operates when the throttle is depressed."

So what that last line confirms to me is that you should never touch the throttle pedal whilst trying to start the car.

Cheers
Dave
 
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