P01010 MAF Rough idle, misfire 2L tdi BRE AUDI

[Rsthaitthir]

Hi Folks.
Firstly thanks for adding me and secondly apologies for opening what appears to be a can of worms again. I have searched and read acres on the subject but haven’t found a definite answer yet. This is a car that I bought recently from family so no come back.. and yes I know its 10 years old but its new to me.
Car: A6 C6 2007 AVANT
Engine BRE099691
Chassis: WAUZZZ4F07N099817
REG:ST56VAX
140k miles
Timing belt done at 135k
OBVIOUS SYMPTOMS:
EML: comes on after 40ish miles. MAF, implausible signal, range / performance, or, circuit A
Car is very rough on start up in the morning or if left for long periods, wont rev, billows smoke but clears after a few seconds and as if you flick a switch it settles down.
Car is rough when idling and misfires slightly when held at revs throughout the range. When driving in a high gear at low speed a misfire can be really felt around 1500 rpm
Apart from that the car is perfect. It will rev cleanly to 4900 rpm and accelerate through the gears without any hesitation. It hasn’t stalled or stopped while driving and go’s like a scalded cat!!
WHAT I HAVE DONE SO FAR:
1. Replaced the MAF 3 times with known good MAF’s and the code P01010 is still shown
2. Stripped front end and inspected hoses and intercooler. No damage
3. Replaced the EGR valve as the full closed stop was badly worn. It did improve it a little but symptoms still persist.
4. Cleaned EGR cooler. All EGR parts are clean and OK
5. Checked diaphragms on turbo and manifold. All holding a vacuum and moving full travel
6. Inserted a clear tube in fuel line before the tandem pump to check for bubbles, oil in fuel etc.. Fuel is clean and no bubbles.
WHAT I HAVE LEARNED SINCE BUYING:
1. The car has sat idle for 6 months
2. The head was off for broken cam followers ( not sure why)
3. T belt and kit done at the same time. 135 k miles
4. Intercooler replaced due split.

Attached are a few photos of the MAF when it lit the light. And photos of the injector deviation at different revs (whatever that is)
At this point I think it could be injectors but I really have no notion.
I have read a lot of posts but found no definite answer to the problem.
Any assistance would be greatly appreciated
also does any body know what make injectors are installed and what’s involved in removing and refitting them.

P.S. If this is in the wrong place please move also how do I change my user name as I managed to misspell it

Cant load photos for some reason

Thanks

[niall campbell]

3421134210Glow plug change for starting

check timing for cambelt

scan the car

EGR works by electric and there is a motor with plastic teeth. Take the end of the egr, you see a large plastic wheel, lift it off and inspect the teeth in a V shape cog system. Mine were worn down after 75,000 miles

[niall campbell]

also I would look at buying a new MAF sensor or even disconnect the wiring to it to see if it makes a difference



HAve you also changed the diesel filter ? There might be water in it that you cannot drain

[Rsthaitthir]

ThanksNiall.
I have replaced the EGR as the full closed stop was worn as in your second photo and allowing the valve go over closed. It did help a little but snag still there. The timing belt was changed 5 k ago so it could be a problem but the car runs perfectly under load and will rev out cleanly. I have had 3 different MAFS fitted, one brand new Oem, but no fix. I just changed the diesel filter, it had only a few k miles on it but had a fair amount of particles in it which look like carbon. The head was off before i bought it and I discovered that the injector and follower bolts are stretch type so shouldn't be 're used but I bet they were.
I found a post on another forum which describes my fault and the fix was INJECTORS so I plan on changing the loom next and pull the injectors at the same time and get them tested. Not looking forward to that as it'll be a costly process
VCDS keeps giving MAF faults and injector deviation shows 2 injectors at + 2.9 and 2 at -2.9 so something is up as far as I can gather.
I reckon I have more than 1 problem so it's not going to be a simple fix.
Thanks again

[niall campbell]

I would then


check timing, if ok then fix injectors


leave MAF until injectors are sorted

[imtattoo80]

Check with VCDS fuel amount that car is using at idle. Should move between 0.4-0.6 litre at idle with worm engine .Maybe went out of specs after t-belt job. If less then you get bad start in colder weather --less than 15 degree cellcius outside . and Runs lumpy at idle and low speed high gear..1500-2000 rpm. But fine when accelerating. I have also 2L BRE . Mine is too low aswell..sometimes walls to 0.2 l. will add little soon. its easy..10 min job. Just check it and see what reading you get with VCDS. Engine-measure block-module 15....i think it was

[Rsthaitthir]

Thanks guys. I had the rocker cover off at the weekend and looked at the loom. It probably has gotten brittle so could be at fault also. I Squeezed the connectors a little to tighten them and this appears to have made a difference to the miss and rough idle but not cured the start up. Any ideas as to the part no of the loom?
I plan on putting up about 600 miles this weekend so I should know better then.. If it keeps going. I'll probably do the loom as soon as I can and then look at timing and injectors after that.
Thanks for your help.