Stalling on startup and at idle in gear

[maxx4wd]

Ok so I've been having an intermittent problem that has finally gotten so bad that my '06 LR3 V8 won't run when it's happening.

symptoms: very rough idle when in gear, when in park or neutral it stumbles a little but not terrible or the motor will entirely shut off upon initial startup (doesn't matter if I hold the throttle part open or not).

Background: Recently replaced (within 12 Mo.) - PCV valve, spark plugs all have been working fine till about 2 weeks ago. Replaced MAF 7 months ago working fine but cleaned it with MAF cleaner just in case. Original vacuum hoses but they all seem to be holding vacuum just fine - no leaks that I can. First thought was I needed to clean TB but I had just done this 4 months earlier - cleaned it anyhow, not much buidup. A new K&N was installed at the same time and I did follow up with cleaning the MAF about a month after (which is the cleaning mentioned above).

I don't get any codes and my first thought was that it was the TB with a very close second thought that it was vacuum. I haven't ruled out a failing TB but at $400 I want to make sure I check everything else before just throwing money at something that may not be the fix.

Third thought would be an EGR issue but not sure how to check that one.

Anyone know how to check to see if a throttle body motor is going out? usually the motor will surge, but I thought it would do it at all times which would lead me to believe my problem isn't a bad TB...any thoughts would be awesome....my PC is down at the moment so I don't have my diagnostic software running and the motor won't stay on long enough anyhow.

Thanks in advance...

 

[catman]

Fuel pump going out possibly?

 

[maxx4wd]

Fuel pump going out possibly?

Maybe, I'd think that would throw a code (misfire or ignition related) but that's possible...I don't think we have cleanable/replaceable fuel filters on these guys...probably just an in tank pre-screen but I could be wrong on that. It's worth a look for sure and it would be an easy fix if it were just a fuel filter...in tank pump may be more extensive but I could test the pressure on the fuel rail to verify...thanks for the suggestion.

 

[catman]

Land Rover Merriam Parts:
Land Rover Genuine Factory Part
Fits 2006 Land Rover LR3 SE
Part Number: WGS500051
Fuel pump assy
Item #10 on image
MSRP
$682.18 Save
$131.23 Online Price
$550.95

Here is an aftermarket kit on ebay if you just want to test the waters without too much expense. It shows a 10 micron filter is inside.

 

[Houm_WA]

Ignition Coil(s)?

 

[maxx4wd]

Land Rover Merriam Parts:
Land Rover Genuine Factory Part
Fits 2006 Land Rover LR3 SE
Part Number: WGS500051
Fuel pump assy
Item #10 on image
MSRP
$682.18 Save
$131.23 Online Price
$550.95

Here is an aftermarket kit on ebay if you just want to test the waters without too much expense. It shows a 10 micron filter is inside.

thanks - I'll check this out...

 

[maxx4wd]

Ignition Coil(s)?

possibility as well...same with the pump I'd think this would throw codes but I think I can test these as well so worth a shot

 

[maxx4wd]

One other thought I had last night...I wonder if a failing injector o-ring could cause this...since its intermittent it might be heat cycle dependent (as far as sealing)...might be worth swapping all the injector o-rings - this might not throw codes unless the injector really failed not sure why a leaky o-ring would cause the engine to die entirely though...rough idle I get...just a thought.

 

[Peter Coetzee]

I recently had the same problem with LR3 HSE TDV6 and it turned out to be injectors. Maybe the same for petrol?

 

[grassclipping23T]

Is the fill cap for the oil reservoir tight?