Ok so my car still doesn't run right, 25+ parts still no better off!

Craig1.8t

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Right made a few posts on here and other forums. Still I'm no further forward. Rather than say what I've done it would be easier to tell you people what I haven't done.

Parts not fitted:
Throttle body,
Crank sensor,
Cam chain tesnioner,
Wiring loom,
Nothing checked internally,
Not a new turbo but checked the turbo, its fine with only minimal play.

The fault is intermittent and I can not give you specific details as to when it does it. Its just random.

Jerks under light throttle, runs rough with airmass plugged in, brand new genuine (2nd brand new as I thought the first was faulty, seems not the be the case) NO air leaks. EVAP delete and N249 delete (Fault was present before doing these mods, still shows its face now)

Spoke to Tuffty about this, he asked me to do some logs, so I did. He found it ran rich then lean then rich and suspected air leak/unmetered air or an air mass, but as mentioned I have brand new maf(s) and no air leak what so ever.

HMMMMMMM.

One thing to mention, the car uses oil and smokes (sometimes) after being on idle a few minutes.

Yet to do to car: SAI Remove and PCV simplify with oil catch tank.

Thanks
 
the wiring to the MAF is ok?

edit: that would have been spotted on the log by erratic MAF readings i guess
 
All I say is good luck. My car burnt oil slightly. I ignored it until it got worse. I pick car up tomorrow after a week of work and investigation. Cylinder 3 had a naff oil pressure ring. And very brittle valve stem seals. So had the whole lot replaced. Pricy job.
 
s3feats was you experiencing random rough running? With my MAF unplugged it runs smooth most of time, but randomly jerks.

Routledge are you reffering to just the smoking at idle or the whole question?
 
Alex C, I've thought it could be wiring related, theres possibly corroding wires and giving bad voltage sometimes, I'm yet to check the wiring loom fully.

s3feats again, I will do all the work my self so just price of parts for me :) and I have suspected rings just never done them as it being a big job for just a trial and error way of finding a problem. I need very soon a new timing belt so might whip head off when I do that. Also want to check oil pick up pipe which I can check when taking sump off to remove rod bolts.
 
Can't see piston rings or valve stem seals being expensive parts do you should be all good. Wish I had the time off work to do it myself. You might as well do what I go the garage to do...replace every gasket and seal. And rings. Good chance for you to upgrade Rods too if you haven't already.
 
Ok, so did you experience any running problems? Also speaking of rods, I did have this in mind, but obviously its dependant of cost. Any ideas or costs and which ones to go for?
 
I did yeah, only whilst pulling away (as this when it would smoke) car would hesitate slightly. So to overcome this I just gave it the beans everytime. Lol.

I drove my car as few times as possible because of this until my local indi Audi specialist was able to have my car in. I even had it recovered to the garage as i wasnt advised to drive it.

Not trying to worry you though, it might not even be same issue. Get a compression test done to see of its rings.
 
I did yeah, only whilst pulling away (as this when it would smoke) car would hesitate slightly. So to overcome this I just gave it the beans everytime. Lol.

I drove my car as few times as possible because of this until my local indi Audi specialist was able to have my car in. I even had it recovered to the garage as i wasnt advised to drive it.

Not trying to worry you though, it might not even be same issue. Get a compression test done to see of its rings.

I will compression test it tomorrow, its been like it months now. I do remember it was running perfect for 4 days, I jet washed the engine bay and it ran badly again. Its a weird one.
 
Stock rods are not forged and no good for 300bhp +, I wouldn't bother to just get a fresh set :)
 
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Can't see piston rings or valve stem seals being expensive parts do you should be all good. Wish I had the time off work to do it myself. You might as well do what I go the garage to do...replace every gasket and seal. And rings. Good chance for you to upgrade Rods too if you haven't already.

Piston rings for a set from VAG cost around £35/40 a piston sadly... then there is the head gasket, head bolts, stem seals (paid about £1.30 each from GSF iirc), turbo gaskets, coolant, oil and filter etc... all adds up and stripping a 20v head is 'loads of fun' :)

You will be surprised how quickly the costs mount...

<tuffty/>
 
Ok, so did you experience any running problems? Also speaking of rods, I did have this in mind, but obviously its dependant of cost. Any ideas or costs and which ones to go for?

Integrated Engineering or Brute rods... I think Bill posted the prices up in another post recently...

<tuffty/>
 
The fact it doesnt run properly with the MAF connected indicates to me thats the area you should be looking at. It suggests something about the air mass readings the MAF is providing dont agree with what the engines actually getting. Typical causes would be an airleak or a faulty MAF thats giving incorrect readings.

Wonky fuelling would also agree with this, however was the ECU actually requesting rich mixture, or was it requesting something else and the engine was going rich/lean independantly of the request?

Presumably from your comments above you've checked for obvious leaks with a pressure test, but have you confirmed correct functionality of all the check valves? Leaking check valves wouldnt show up in the pressure test.

Have you checked the fuel pressure regulator for any debris? Heard of a few S4's were the fuel lines have started to degrade and the rubber bits have ended up in the pressure regulator, causing fuel pressure to go all over the place.
 
Had smoke test. Not replaced any check valves but checked most of them. Replaced everything to do with fuel supply except the fuel lines.
 
The past few days has been jerking (As if if wants to run out of petrol kinda) Its worse when first started up when cold.
 
The past few days has been jerking (As if if wants to run out of petrol kinda) Its worse when first started up when cold.

Hmmmm, this sounds a little similar to my mate's S3's problem when the Crank Speed Sensor went. No faults. Just jerking randomly.

New CSS solved the issue. Wiggle the wires coming off the sensor before the plug. I did this by accident whilst investigating and thus found the problem.