Disco 2 Intermittent Starting Problem (and lack of power)

Waiting on my Foxwell NT510 diagnostic tool to arrive (took Sierrafery's advice - couldn't afford the more expensive options - will also use this for my VW), but pretty sure it won't help me with my current problem with my 2003 Disco 2 Td5:

In the last week or so we have had an intermittent starting problem - seems to start effortlessly first time every time in the morning, but after a run and switching off the ignition and then trying to re-start again it doesn't fire first go anymore. Pretty sure starter motor (refurbished starter solenoid several months ago) and battery are all good (battery is only 5 months old and checks out okay with multimeter test). Also, installed new FPR several months ago as well and everything was good following that. Also, injector loom was replaced a few months ago as a precaution even though the loom and red plug connection at ECU was spotless.

So, intermittent starting issue has presented itself and this seems to coincide with a lack of power - engine doesn't really get moving until accelerator is pressed a fair bit - lot less responsive than it used to be.

What is the most likely cause? Don't really want to entertain a new fuel pump or injector seals - no reason to suspect either really (though I do confess to being a mechanical novice).

Seen this on the "LR Direct" website though and got me thinking a "possible (and likely) fix" might not be that expensive:

"Fuel filter head bleed valve WJN500110 is for the Td5 engine fitted in the Land Rover Defender and Discovery 2. The part number for the non return valve fitted next to the bleed valve is VUB503950. Replacing these two valves can solve issues with poor starting engines."

Is it worth replacing these two valves on the fuel filter housing? [Fuel filter is a Mahle and I changed 12 months ago.]

Looking for likely and cheap potential causes of this problem at this stage; if no result forthcoming then it's off to the LR mechanic I think.

Might check MAF with the multimeter - might explain low power at low revs when taking off; the MAF is the original one and I guess it is possible that I may have damaged it when I cleaned it with MAF cleaner several weeks ago? Not sure though if a faulty MAF could also lead to intermittent starting problems, and of course there is the unlikely scenario where I have two problems concurrently?

Any thoughts anyone?

it's hard to guess... wait untill you see if there are any fault codes logged, eventually read some live data cos if it starts well from cold but hard when the engine is warm could be the crank sensor or the fuel temp sensor.... or many other things

Still waiting on delivery of the Foxwell you recommended as a cheaper alternative to Nanocom or Hawkeye Sierrafery to hopefully help me diagnose the fault/s. In recent times:

• new battery (checks out fine with multimeter),
• new injector harness fitted and absolutely no evidence of any oil ingress into ECU
• new FPR (original had started to leak)
• EGR removed (bypass fitted)
• starter solenoid overhauled (used quality kit)

Disco 2 Td5 (2003) running just fine for a while after the above changes - no issues at all.

Then, for some reason I decided to clean my original MAF and MAP using MAF cleaner, and, I guess some short time since that moment I have noticed a lack of power (vehicle has lost its oomph) when taking off from a standing start - really have to use a lot more accelerator to get the thing moving than I did previously! A little while after noticing this I then noticed that the engine would crank when starting but sometimes would not fire up (as if fuel starved - pretty sure it's not a battery or starter motor issue) - previously started strongly first time every time; seems to start in the morning okay, but if you go for a drive and then stop the engine for a while it has trouble re-starting! So, currently have a power at take-off and an intermittent starting problem - not sure if they're linked or separate?

Not sure if the Foxwell will tell me anything when I get it, but maybe one (or possibly two) of:

• fault with original temp sensor on new FPR?
• fault with crank position sensor? (but thought if this failed then it would not start at all rather than start intermittently)
• fault with fuel pump (original pump, but no strange whining noises or fuel leaks anywhere)?
• fault with MAF?
• fault with MAP?
• fault with injector copper washer/s? (but sump oil level steady and no smell of diesel in sump oil)
• fault (blocked) with air bleed valve on fuel filter head (someone told me this is a likely candidate)?
• fault with NRV on fuel filter head (but not really sure about this one at all)

Only other thing is I also let the fuel tank level get pretty low around the time this all started happening recently. There have been no warning lights indicating any issue so not sure if a diagnostic tool would pick anything up if nothing logged (I assume problems logged coincide with a warning light showing at some stage?).

Any further thoughts? Was thinking of changing the air bleed valve, as it is a cheap fix, a likely candidate and pretty easy to do?

those two sensors i pointed in my previous post are the most suspect but if they'll show well on live data and no fault codes logged the problem might be with the fuel supply which is not covered by diagnostics.... can be the injector washers too but those should affect cold starting too

Thanks for the advice sierrafery. Will check the crank temp sensor as you say - hear it's a real pain to access/remove though? If it has indeed failed, won't it not allow the vehicle to start at all rather than causing intermittent starts? Will it show as a fault if I interrogate with the Foxwell when I get it?

Will also check the fuel temp sensor you mention - possible it could have been damaged somehow when the new FPR was installed. Presume I can check the temp sensor with a multimeter and/or Foxwell NT510 when it arrives?

Will either of these two sensors (likely culprits you say, at least probability wise) being faulty also explain the lack of power on take-off (need to really depress the accelerator and get the revs up before I get moving from a standing start)?

The crank sensor is heat sensitive and it's quite common to make tricks when the engine is hot it's also an important element of the addaptive strategy so if it's input is not perfect it can create all kind of trouble without triggering the MIL or a fault code... the FT sensor can affect hot start if it's reading high also without fault code logged... better be patient and wait for the Foxwell

sierrafery said:

The crank sensor is heat sensitive and it's quite common to make tricks when the engine is hot it's also an important element of the addaptive strategy so if it's input is not perfect it can create all kind of trouble without triggering the MIL or a fault code... the FT sensor can affect hot start if it's reading high also without fault code logged... better be patient and wait for the Foxwell

Click to expand...

Thanks for the advice - they say patience is a virtue! But I assume you're saying that a possible fault with the crank sensor and/or FT sensor won't necessarily show up on a diagnostic tool (like the Foxwell NT510)? Can you think of any link with the distinct lack of take-off power compared with earlier?

Anyway, your advice has been first-class - just glad I haven't had to cross your palm with silvers just yet?!

I said they might not make the ECU to log a fault code but if there's any problem with theyr's inputs it will be clearely visible with live data

Okay, received Foxwell NT510 on Friday: pre-loaded with VW software. Used it on Saturday so I could change the brake pads on rear wheels of VW CC - so may have paid for itself already. Today, Sunday, I paid for and downloaded and installed additional Jaguar Land Rover software for 60USD.

2003 Land Rover Discovery 2 Td5 auto:

Okay, went out late this afternoon and found the "OBD 2" connector on the LHS of steering wheel, low down, just above the left foot rest pedal. Turned ignition to position 1 - NT510 booted up - all good!

Decided to try and start the engine. Well, engine started first go - no problems at all (and it's very cold today) - this fits with the intermittent starting. Let idle for a little while (parked in driveway) and then decided to record live data. Decided to then squeeze the accelerator - engine was rough under light acceleration (slight rumble and rocking) and returned to normal when engine allowed to idle. Got cold and dark very quickly so had to come inside.

Anyway, these codes showed up on the NT510:

Engine Speed outside bounds for cruise (Where Fitted) Active
Vehicle Speed outside bounds for cruise (Where Fitted) Active

Now need to read up on the NT510 manual, do a bit of internet searching and see if I can work out what my issue is.

Started graphing live data and I though I saved the graph, but when I looked I have multiple screens of tabular data. Anyway, at least I think I might have a chance of working out what the problem is now? Any thoughts on what I need to look for now?

do you have cruise control on your D2? ...;. also it would be good to post here somehow the recorded live data

sierrafery said:

do you have cruise control on your D2? ...;. also it would be good to post here somehow the recorded live data

Click to expand...

Yes, has cruise control. No warning lights showing on dash panel (as before) - just those two codes came up in the NT510. Will need to check the NT510 manual - haven't had much chance to peruse it yet - to see how I can print out the graphs or live data so I can maybe make some sense of it all.

Okay, printed this recorded live data out to pdf on laptop and copied here - recorded this while engine idling and light acceleration (as I mentioned, as soon as accelerator squeezed a little the engine seemed to then run a bit rough - slight rumble and rocking). Can't seem to find the live data graph I thought I recorded and saved at the moment - will have to have another go in days to come (though vehicle is low in fuel - so might have to top up with a gerry can rather than risk a drive down to the service station. Can't see anything here that stands out to me?


Diesel TD5, Read codes, ECU information, Live data, All data
Data list
Ambient pressure 100.66 kpa
Engine speed 774 rpm
Idle speed error 20 rpm
Vehicle speed 0 km/h
Coolant temp 26.8 °C
Inlet air temp 13.2 °C
Fuel Rail temp 19.2 °C
Mainfold pressure 102.62 kpa
Air flow 66.8 kg/hr
Driver demand 1 0.73 V
Driver demand 2 4.29 V
Driver demand supply 0.00 V
Turbo MOD % duty ratio 0.00
EGR MOD % duty ratio 0.00
Driver demand 3 4.64 V
Driver Demand pedal 3 Track
Clutch pedal position switch DEPressed
Low Ratio switch NOT in low ratio
Brake switch 1 OFF
HEVAC Aircon Fan request NOT REQUESTED
Aircon fan drive ON
HEVAC aircon clutch request NOT REQUESTED
Aircon clutch drive OFF
Cylinder No.1 2 rpm
Cylinder No.2 1 rpm
Cylinder No.3 -2 rpm
Cylinder No.4 0 rpm
Cylinder No.5 -1 rpm

Watch the live data while you are pushing the clutch pedal and see if it changes it's status cos i presume it wasnt depressed while you recorded the data and it appears as it was and if it doesnt react to the pedal and the input is like depressed the fuelling is reduced

EDIT, just realised it's auto so forget about that.... the driver demand supply 0 is suspect but it might be only a glitch cops as long as track's 1 and 2 are OK the supply can't be 0 in reality

sierrafery said:

Watch the live data while you are pushing the clutch pedal and see if it changes it's status cos i presume it wasnt depressed while you recorded the data and it appears as it was and if it doesnt react to the pedal and the input is like depressed the fuelling is reduced

EDIT, just realised it's auto so forget about that.... the driver demand supply 0 is suspect but it might be only a glitch cops as long as track's 1 and 2 are OK the supply can't be 0 in reality

Click to expand...

Yeah, auto. Will have to try again later this week. Need to graph, save and print-out the graphs for idle and whilst accelerating; will be interesting to see if it starts first time again. Have never had the engine rock the way it did whilst under acceleration. The output from scanners is not exactly self-explanatory; will just have to persevere.

Okay motosleuths - more information has been revealed!

2003 Discovery 2 Td5 SE Auto - update:

Diesel fuel level low so decided there would be no real harm risking a trip to the local servo (only 1 km from home) and putting in 50L of fuel into a tank that was very close to empty (had been that way for a couple of weeks).

Okay, started from cold first time - no prob's at all at idle (apart from very slight rumble). Again, with acceleration at idle there was a more noticeable engine rumble. Decided to head off! Ran very rough but got to servo.

Engine turned off at servo and put 50mL of Flash Lube (for Diesel) into tank then went to put 50L of diesel into the tank. Well, took forever and a day to get the diesel in. Diesel bowser kept cutting out and foaming diesel kept rising up the fuel tank fill tube and then the level in the fuel fill tube would go down to come right back up when more fuel was put in!!! Is there an air lock or blockage somewhere?

Anyway, tank now with 50L in I tried the ignition. Started no problems at all first time! However, trip of 1km home was rough - engine not running smoothly at all (but pretty much okay at idle with no acceleration). Response to acceleration was bad. Got home and noticed that when accelerator pressed a lot of grey (blue tinge perhaps) smoke was coming out of the exhaust. Smelly, but certainly not an oil smell.

All this time (starting at home and returning home) I had the Foxwell NT510 connected to record live graphical data. Will try and make sense of it.

Any thoughts anyone?

Can you save and attach that data log here somehow?

I thought data would save as live data graph? When I downloaded from SD card into Foxwell software and printed out to PDF I got this (no graph):

Vehicle : /scan/landRO~1/
Test Path : Land rover, Automatic selection, Manual selection, Discovery, 1998-2004, Engine, Diesel TD5,
Diesel TD5, Read codes, ECU information, Live data, All data
Data list
Ambient pressure 100.66 kpa
Engine speed 774 rpm
Idle speed error 20 rpm
Vehicle speed 0 km/h
Coolant temp 26.8 °C
Inlet air temp 13.2 °C
Fuel Rail temp 19.2 °C
Mainfold pressure 102.62 kpa
Air flow 66.8 kg/hr
Driver demand 1 0.73 V
Driver demand 2 4.29 V
Driver demand supply 0.00 V
Turbo MOD % duty ratio 0.00
EGR MOD % duty ratio 0.00
Driver demand 3 4.64 V
Driver Demand pedal 3 Track
Clutch pedal position switch DEPressed
Low Ratio switch NOT in low ratio
Brake switch 1 OFF
HEVAC Aircon Fan request NOT REQUESTED
Aircon fan drive ON
HEVAC aircon clutch request NOT REQUESTED
Aircon clutch drive OFF
Cylinder No.1 2 rpm
Cylinder No.2 1 rpm
Cylinder No.3 -2 rpm
Cylinder No.4 0 rpm
Cylinder No.5 -1 rpm
========================================

AND THIS:

Data list
Ambient pressure 101.58 kpa
Engine speed 0 rpm
Idle speed error -858 rpm
Vehicle speed 0 km/h
Coolant temp 11.9 °C
Inlet air temp 12.0 °C
Fuel Rail temp °C
Mainfold pressure kpa
Air flow kg/hr
Driver demand 1 V
Driver demand 2 V
Driver demand supply V
Turbo MOD % duty ratio
EGR MOD % duty ratio
Driver demand 3 V
Driver Demand pedal
Clutch pedal position switch
Low Ratio switch
Brake switch 1
HEVAC Aircon Fan request
Aircon fan drive
HEVAC aircon clutch request
Aircon clutch drive
Cylinder No.1 rpm
Cylinder No.2 rpm
Cylinder No.3 rpm
Cylinder No.4 rpm
Cylinder No.5 rpm

Need to see how to get print-out of GRAPHICAL live data. What's the go with that idle speed error??? Does this shine a light on any likely suspects?

That idle speed error is quite irrelevant for diagnostic purpose, it's a calculated value to show the difference between the demand and achieved rpm.... not an issue

according to the data it doesnt seem a management issue , maybe fuel supply or mechanical