TD4 Sick - Any Ideas?

Hello Fellers,

I've been having some problems with my TD4 recently, and since i will need to do most repairs myself, i wondered if you might offer some advice at where to start solving these symptoms:


About a month ago, while on route between Brno and Prague (about 200km), i picked up some fuel and carried on. All seemed fine, but when i got to a traffic constriction on the motorway, and had to travel single file and slowly, the engine started running erratically, but only at low revs (ie when moving slowly, and on idle). I thought it might be dirty fuel, and since as soon as i started moving a little faster the engine ran smoothly, i carried on. Applied some STP cleaner and water remover too (did help a little).

After several weeks of this, and it happening on and off (erratic idle and occasional stall at idle / low revs) i thought id better get to the bottom of it.

Its been connected to a computer, and the fault codes it read were (the engine light only came on during one stall, no other warnings - ever.)

565 - Filling Pressure Sensor (? translated from czech)
256 - MAF
400 - Fuel Pressure sensor.

The garage that did this reset the comp, and since it has been behaving better, but still displaying the problem. The car in the last year or two has had: New High Pressure Fuel Pump, New Battery, New Low Pressure Fuel Pump, 3rd Injector, New Turbo vane actuator, New Turbo.

The ONLY change i can notice on the car since this started happening is the temperature gauge for the cooling now moves over a range, rather than staying dead steady as it has done the last 5 years - moving from its central rest position down to the bottom of the thermometer-in-water logo (so not a WILD change, but enough to get me curious) - dont know if its related though.

I would love this to be just some stupid blockage in the fuel system, however the way it displays the symptoms is relatively random (at least to me) but usually only starts once the car has been running a while (after properly warmed up and a journey somewhere)

Any ideas what things i could look at first? Ideally, starting with what i can check / clean for low cost or free? Alternatively, if anyone thinks they know more specifically what this could be then i would welcome any info. But lets face it, any info is welcome..thanks in advance

Some easy checks for yer. . . .check yer three inlet turbo rubbers for any nicks [the three large rubber pipes] or disconnect the maf [if it runs better then check out Rover Ron's gismo] if not re- connect . . . .change fuel filter [if it ain't bin done as per schedule] if your mill light came on pre computer reset and after checking above then a weak low pressure fuel pump is possible [two on your model] . . . .if any of above is suspect then look more in depth in search. . . . .hope this helps yer

Right, will try disconnecting MAF today / tomorrow (had planned to try already but it slipped my mind). Just been for a drive, and once the car warms up, it starts it erratic idle, then, when alowed to reast a while, its fine again. Also, somethimes it jsut "gets better" for a bit...could it be bad / loose contacts to injectors or something? Would checking to make sure all the earths are ok help?

The fule filter was changed about....4000Km ago? But no harm in changing it again (might try over weekend also.)

Thanks for the advice so far.

also you might have had some durty fuel at some time . . . .try sum injector cleaner Millers or red ex [make sure its the diesel type though] un best oh luck Earthling

Also just found RoverRon's thread about the freelaner ecu harness tech bulletin - might be worth a try too - any idea which contacts to unplug, clean, and replace to try and see if it makes a change? Where would i find them?

Just fiddle with the wiring to the fuel rail pressure sensor while the engine i idling and you might just hear the engine note change or misfire. Remove its electrical connector and check for corrosion.

Cheers - thats my saturday sorted then ;-) Will let you all know if it works...

Right, cleaned all contacts thoroughly, and although certain things improved slightly (seemed to run a little smoother) - the main problem of the engine cutting out at idle / low revs is still present. Tomorrow will disconnect MAF and go for a drive. Also applied diesel additive, will see how that goes.

also check this connector:

http://www.landyzone.co.uk/lz/f9/found-plug-under-bonnet-78638.html

as it had an adverse effect on mine being disconnected

Thanks, connectors checked and cleaned for good measure. MAF off changes driving characteristics a little, but does not remove the stalling at idle problem.

Now ive had time to log it a little, the problem seems to only occur when the car has been running for about 20mins or more - at normal driving speeds / higher revs you dont notice it at all, probably why i didnt notice anything was wrong on the motorway, but as soon as i brake for lights or something, the car stalls (autobox, so under braking at slower speeds it goes into neutral right). If the car is then left to stand 10 mins, it will start and idle fine for a short while, if left to stand for longer, its perfect and carries on again for 20 mins until the problem returns.

If it was an electrical problem, i would expect it to be present regardless of if the car was used for a while or not.

OK, next i would do an injector leak test. excessive leak back will cause low fuel pressure during cranking and low rpm. it is normally accompanied by poor starting but I'd still be curious to know if they are all sealing properly.

ok, will go to local LR guy here to do that, presumably its not something i can do without some sort of pressure sensor?

p.s Found a really good chap for LR stuff over here in CZ, Land Rover :: British Cars Ltd s.r.o. , seems he does a fair few expeditions and he's certainly not a lying stealer.

It's easy to do yourself if you want to save money. All you do is prise out the spring clips holding the plastic pipe connectors into the top of the injectors and carefully pull out the plastic connectors. (don't attempt to pull off the hoses)

Clamp the pipe on the left so no diesel can come up the pipe to the 4 connectors.

Turn on the ignition (not start) and look at the top of the injectors to see if diesel leaks from any of them.

Do this test with the engine as hot as possible as this is when you get the problem.

Also don't rule out electrical problem yet, electrical connections and sensors can be affected by temperature. The crankshaft sensor seems a logical one to suspect.

Right, thanks for that great method, ill give it a go.

Another development i've noticed is, that as well as the temp guage swaying, my trip computer has reset itself twice now overnight, never did that before (first time i thought maybe i did it, second time i was sure). Not sure if its all related, but ALL these things started happening at exactly the same time. What controls the trip-comp? The ECU? Also, did not have total power loss, since radio settings are fine still.

I am considering a trip to the UK (need to get new MOT soon) would anyone be kind enough to recommend a GOOD independent non-lying garage in the west London / London area please?