TD4 fuel supply issue?

[atwood]

The wife has been driving her 04 TD4 2 door for more than 200k kms very happily, in fact she loves it and it has been very reliable.
Some years ago we had to replace the fuel pressure pump... it was running (just) but starving for fuel and stalling... the error condition made it clear what the problem was and replacing the pump fixed the problem.

We now have a much subtler problem... only intermittently the engine stalls and sounds like it's starving for fuel again.... there are no error lights and/or fault codes and I can't always recreate the problem. Fuel system looks clean.... many different tanks of diesel since the problem started and fuel pressure seems OK.

Can anyone tell me whether I should pull out the fuel tank and replace the lift pump? This is a bit of an expensive next step, but I am out of ideas and I would value some opinions.....

[woko]

Get your battery tested. Parents 01TD4 was doing the same thing and turned out to be battery.

[atwood]

OK... it's hard to see a correlation, but I am grateful for any suggestions... Can't remember if/when we replaced the battery, but we must have at some stage in the last 7 years!

[woko]

I know it's hard to believe but theirs used stop about 1/2 way down their driveway. I'm not sure if it used to log a fault about low voltage but would start with no troubles and then stall. It's just the joys of a common rail diesel. Have a look at the disco 3-4 and l233 range rovers there's heaps of funky problems due to batteries

Sent from my GT-I9295 using AULRO mobile app

[atwood]

Believe it or not - we still have this problem!
Battery is fine. We cleaned out the fuel system and replaced the lift pump and filter, that being - we thought- the most likely source of the problem.
We thought we had fixed it, but a day or so later the vehicle stalled and still intermittently runs rough. Again it sounds as if it is starving for fuel.
Still there are no warning lights or errors recorded in the log.
It seems to me that there must be an intermittent fault in the high pressure pump but last time I had a pump problem - we generated an error condition, this time nothing!....
I really don't want to just replace another part to see if we can fix it. I am still interested if anyone has any other ideas.....

[woko]

Did you clean out the sedimentor when you replaced filter and pump?

check the wiring going to the fuel rail pressure sensor. These have a habit and corroding in the plug on to the rail sensor. There is a harness repair kit available to replace it.

block off the EGR to test if it is leaking excessively.

I would also carry out injector leak off test.
This will explain how to do it. its for a BMW but is the same engine.

http://www.londonroadgarage.com/images/M47%20DIESEL%20DIAGNOSIS%20GB-13-004-03%20kw.pdf

[atwood]

At long last it looks like the problem has been solved!
LR dealer finally diagnosed a fuel pressure regulator problem and wanted to replace parts valued at something over $1K.
Following the input from Woko below - I instructed that they first install just the harness repair kit... parts value about $100. Work completed (and I wish I had done it myself) and car is running normally... she is happy - my life is less complicated and Woko is a legend!

[woko]

Good to hear that it running as it should.