2.5v6 allroad intermittently very poorly

[Adam.ch]

Ive spent hrs and hrs reading through threds trying to figure my problem, so any help would be genuinely appreciated...
Ok, so. Allroad 2.5 v6 with 165k bought it after just(2k) having a full belt, pullys,bolts tensioners ect changed. Developed a stutter/misfire feeling problem and sometimes would stop and not start, from cold would run fine then stop, other times wouldn't start from cold. Other times would run 100% fine. I had the injection pump edc unit repaired. Re installed it, blead the fuel (ball ache) and now has no bubbles.
From cold she starts but with a rattly missfire as though the pump is being turned off n on again intermittently. She is also cold starts with excessive diesel smoke. As she warms up the smoke clears but still has the misfire/pump shutting down momentarily. Sometimes she will sit running happy, others she will stop. The coil light does flash but the code reader brings up no codes. Sometimes she will drive 100% others like a bag of spanners and will shut off whilst driving !
Hot start within 20 min of driving she will start, within 1-4 hrs she wont start.

Any ideas, thoughts or questions warmly welcomed
Thanks in advance

[bluezie]

Forget a generic code reader, get it on VCDS and find what codes are stored. If the fault light has come up, there will be codes stored.
The symptoms are like air in the system, have you replaced the leak off pipes? these become porous and let air into the system and cause misfires and poor starting. It will throw a fault code if there is too much air in the system, something like - 'random multiple cylinder misfire due to lack of fuel'
If not air, it sounds like an intermittent electrical fault, which will show as a code.

[Adam.ch]

Forget a generic code reader, get it on VCDS and find what codes are stored. If the fault light has come up, there will be codes stored.
The symptoms are like air in the system, have you replaced the leak off pipes? these become porous and let air into the system and cause misfires and poor starting. It will throw a fault code if there is too much air in the system, something like - 'random multiple cylinder misfire due to lack of fuel'
If not air, it sounds like an intermittent electrical fault, which will show as a code.

Hm. I was suspicious when it came up with no codes. Before i had the pump edc apart there was air in the clear fuel line. It took ages to get rid of it all but i now have no bubbles at all so im confident im not getting air in the system now. Agreed it seems to be electrical. My understanding is it had been mechanical it couldnt be intermittent as it would either be broken or ok.
Im hoping to try a different code reader this wk. With any luck it will find some codes and hopefully get a start point for diagnosis.
With it over fueling on start up would it be more likely to be crank sensor issues? If i disconnect the temp sensor when shes running the revs rise so im guessing its working. Is there any way of testing crank sensor today before i have to try to drive it to read the codes on thursday ?? It looks like it just runs a vac' pipe from the sensor. If i disconnect the pipe will i get a noticeable change indicating it is working ??

[bluezie]

I think if you haven't got VCDS, you need to get whoever is reading the codes to dig deeper and check through all the measuring blocks to check all the temperatures, pressures, timing, injected quantities, cylinder deviation etc etc etc. Then perform the output tests to check operation of things like EGR valve turbo VNT mechanism, and fully advanced and retarded ignition timing.
Might need to take the car for a drive and do some live data logging.
Very often the fault codes don't give a definitive answer, by point you in a certain direction. VCDS is sometime very useful, and sometimes essential to go any further.
When you get the codes read, make a note of not just the code but ALL the associated text.

[Adam.ch]

Right, sounds like ive got a plan for thursday. Not to sure what program he's running on his laptop but he semp confident he would be able to read stuff.....finger crossed.
Ill update on thursday...thanks

[Adam.ch]

Bit of an update...
Plugged a friends laptop in and its telling me theres no reading from the engine speed sensor ?? Has anyone got any advice/ help from here ??
Thanks in advance

[Adam.ch]

I have taken the old crank sensor out and the end that was inside has a big wear mark. It looks like the pick up point has bn rubbing on the sensor ? Why would this happen ??

[Adam.ch]

Ok, ive bn drinkin wine and thinking about the problem.
Would camshaft wear have enough movement to hit the sensor pick up ? Surely not ? Theres a grove work out about 2-3 mm deep work out of the edge of the end !! Not directly across the middle of the end, just next to the silver metal magnet.
I changed it for a new one and she still started very lumpy, but then sorted its self out and drove perfectly for about 8 mile. Then i left her to cool for half hr, went to start her and she was so lumpy she kept stopping. Left it another 2 hrs n she started without lumpynes ??

[bluezie]

Camshaft wear would not affect a crankshaft sensor!
But something is wrong if the sensor is being hit. Either main crank bearings are severely worn, the flywheel is broken, or debris is in the bell housing.

[Adam.ch]

Agreed, something is wrong ! I recon it been worn 3mm deep but off centre not across the pick up ?!
As i find stuff like this im not sure if im discovering additional problems or if there linked !
Would poor/incorrect/ to much/little oil affect the valves enough for a sensor to detect something and make it shut off ?

She is too poorly and temperamental to drive her so i cant take her to anywhere to get her scanned?!