a3 tdi multiple problems!! (doing my head in now please help)

tdi-man said:
just checked in options . shop name is empty.

code(ws) 00000
vz 000
equip number 00000
Click to expand...

just enter some data for the shop name and equip number as some controllers will not allow coding etc if the vcds has no data filled
 
ok will do put vcds lead away now raining here.....

use to work on an old 812.4 lead
 
if i pull vacuum pipe of egr dia and seal end of pipe with bolt as a temp measure will that shut egr of ?????





a8 tech said:
consider the valve timing on the exhaust cam check mvb's torque figure not by using the timing tools as its not unknown for the cambelt to be set up correctly but when you adjust the tension you pull on the exhaust cam pulley and mvb 4 if I remember will show the correct value, drain the fuel from the filter housing and poor it into a glass and check for soot.If there is soot/oil present if its soot then remove the injectors and inspect the cylinder head seats very carefully if pitted post photos
injector readings in mvbs will always vary but a true test is to check fuel pressure at the tandem pump as well as delivery rate

other options when running issue occurs increase or decrease pre fuel pressure and reduce egr flow to see if this balances the combustion more smoothly

so valve timing, fuel pressure, egr flow plus check air pressure and quantity readings if possible and if one cylinder deviates in mvb for injectors then there may be some mechanical issue but after saying all this egr bounce can cause this symptom but with the correct tools you can delete egr function allowing more clean air into the combustion

how to check valve timing with vcds
Display group 4

Measured values
880 /min
5.0 °n.OT
4.0 °KW
6.34 ° THIS MUST BE AROUND 2.5 FOR CORRECT VALVE TIMING
Click to expand...
 
If its only at idle then disconnect the air mass as this will shut egr off but mil will come on
You can blank the egr to test it but this will put the mil on for egr through put to small
You mentioned the remap and egr off solution also
If you just wish to eliminate egr the try either the airmass disconnect or egr blank
Please note without seeing the problem I must advise you that if its not excessive it may not be a major problem but just the combustion process causing the lumpiness due to egr bounce (dirty air)
If disabling egr sorts it out then your left with the fact that you will have no N0X regulation and you are polluting the atmosphere.
I'm not one to preach just highlighting the point
Let us no how it goes
 
ok many thanks for that ive been looking for answers to this probelm for ages.

is egr bounce a common fault ??

just updating brakes this week then will think about the remap and egr blank of in map.

i will try air mass disconect over the week end and see what happens.
 
NHN said:
I knew I was going to enjoy you being a new member, knowledge is a good thing on any forum for all, lmfao.

I have a question, A3 sportback, 2.0 tdi, possible mechatronic having a hissy fit, but when started up 1st thing & go to pull away, you stick in drive, put foot on gas it falters/hangs at 8-900 rpm as in idle & takes a fair few seconds to come alive even if you floor it the revs dont pick up at all, sat at idle almost even if foot down on gas pedal, then all of sudden revs kicks in & all good usually for rest of day or until left sitting for a while again, now if I was to start car 1st thing from cold, then leave in park & give it a good blast on the pedal for a few seconds so revs are up, then stick into drive it would drive of normal revving fine no delays.

Any ideas as I'm leading to mechatronic atm, but tried fuel filter, checked under bench pump is feeding fine to the filter, could try tandem & injectors, but why would it once revved few times then work perfectly, would the mechatronic affect the car in that way so much if on way out?

Thanks in advance.
Click to expand...

reading this again I have thought of another possible cause

So you feel there may be some engine issue?

We need fuel pressure and max airflow plus throttle position correct fuel and coolant readings as theses are all affected by resistance then any deviation could cause incorrect response

ie idle at the pedal is 0.5 volt and full throttle is 4.5 volt leaving .5 volt either end for fault recognition feedback

Possible woffle but throttle pedal readings may be a possible

As it start first time then the pressure is fine but is the air or throttle response correct

The throttle position can be reset if I recall also you could check the mvb for throttle position end stops at the accelerator peddle

so if the pedal readings match in the engine ecu and dsg and the gear recognition is correct check rpm input in the box and this could eliminate engine related problems and highlight the mechatronic rpm input or clutch flare up

If this is bllocks then ignore me lol
 
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yes egr bounce is consequential of the process for reintroducing burnt air although the ecu knows its coming into the combustion process its like drinking a nice pint and near the end you get a few floaters lol
 
another idea is what what happen if you turn the alan key setting up in the tandem pump ?
 
Lost me there, the only alan key i recall is the port to check the fuel pressure
 
oh was told you can turn the presure up and down by adjustment on tandem pump ?

not sure if this would put fueling up ?
 
ok i will ask chap tomo and post info...
 
My tick over is getting worse - left work at lunchtime and it was all over the place.

Left to come home tonight and my tick over raised itself to 1000RPM - weird.
 
ok guys so ive just replaced the second coolant sensor, the car started fine right untill it got up to full temperature then it struggled again :(. but i noticed that when the climate control is switched off the engine judders really bad, but when i switch it on its perfectly fine and the engine runs like normal. so its confusing me a little now as to what it can be as surely it would be doing it all the time either with or without the climate control on?

any help appreciated. cheers

Dan
 
audi upgrades
Ok guys so ive just replaced the second coolant sensor, the car started fine right untill it got up to full temperature then it struggled again :(. would you guys say its a new starter motor now or could it be something else?

Also i noticed that when the climate control is switched off the engine judders really bad, but when i switch it on its perfectly fine and the engine runs like normal. so its confusing me a little now as to what it can be as surely it would be doing it all the time either with or without the climate control on?

Any help appreciated. cheers

Dan
 
turning the a/c starts a chain of command

from the top of my head

a/c signals to j519 then to engine ecu to boost the idle to allow extra load demand and the alternator monitors this via a df signal pulse width modulation to the engine ecu

adjust the base idle to the higher value

poor warm starting

possible cranking rpm below 250 rpm caused by increase wear on the starter or high resistance on the starter cables or battery which in turn stops the injectors opening because the engine ecu does not recive the correct rpm speed

also poor tandem pump residual pressure

check with vcds the engine cranking speed when warm
 
Ok that doesn't mean much to me lol I'm not that technically minded :(.
What do you think would solve the problem of the rough idling when the aircon is off?

Would you say replacing the starter motor would fix the struggling to start when hot?
 
Ok that doesn't mean much to me lol I'm not that technically minded :(.
What do you think would solve the problem of the rough idling when the aircon is off?

Would you say replacing the starter motor would fix the struggling to start when hot?
 
I'd go with new/replacement starter for warm issue, usually old starter suffers from heatsoak of the gearbox, as its fairly simple to change, then do yourself, as cost of replacing in labour with audi would be same as the part, I've done both my cars & the difference in starting was vast.

Now as we're on a forum, we're speculating, so nobody can guarantee your issues are this, but based on fair few others, new starter can only be a positive step anyway.

Gizmo, before clicking POST again, wait a little bit longer as you keep double posting.
 
Yeah I'm just asking on here as I know there's some very kNowledgeable people on here :) and alot of people have had the idling problem so trying to gain from their experience of what solved it.

Sorry about the double posting I am only clicking it once but I'm viewingon my phone so it must be that.

How would I adjust the base idle? Is this a proper fix or just a shortcut way out?

Thanks
 
ok so i've just fitted a new starter motor in the a3 to try n fix the starting problem and...nothing! :( if anything its got worse :( and obviously its still juddering :'( any more advice please guys?

thanks in advance
 
Urmmm thats interesting, so ok give us a list of what you've done so far please.
 
ok....not a lot really but, new injector wiring loom, new coolant temperature sensors and now new starter motor, new fuel filter, cleaned out EGR valve and thats about it i think.... any ideas? :(

EDIT: oh and a new throttle body

iv read about it being a the battery? is it worth getting it tested?
 
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You really need to confirm the problems with some evidence before replacing things

I would only replace the starter if the cranking rpm was below 250 rpm and in the knowledge the battery is in order plus the engine /gearbox earth and the starter wire

You need to check the fuel pressure and also the injectors values

Also check the fuel for soot

Using vcds check your measured value blocks 13 for injectors and also try and use the advanced mvb feature so you can see fuel, air and coolant temp at the same time and also air volume and egr

Also include the valve timing reading

This will show you what's going on because your description points towards low cranking rpm or insufficient fuel delivery/pressure

I understand its hard but its even harder to explain from a lap top
 
ok thanks so how do i get vcds? have you got a link so i can buy it?


also the fuel was black when the filter was changed so it was flushed to clear it up and its a lot better now
 
could i have fitted anything wrong on the new starter o anything to have made it stugle?
 
flushing will only remove the current deposits, you need to establish if there is soot present in the fuel which indicates combustion blow pass from pitted cylinder head injector seats or poorly seated injectors/ seals

nhn sells vcds
 
Thanks A8, yes I do sell the genuine vcds PM if interested.

Also if a battery is on the menu, then I suggest an uprated version that audi do supply, Varta Ultra Silver Dynamic, fits the 8P perfectly & certainly better than the stock Varta Blue they fit.
 
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....and now the ESP light and the power steering light are on :banghead:
 
TBH A8 is very knowledgable, he's right & I dont want to seem like I'm hunting for a sale, but vcds would be helpful atm for you, considering audi's hourly rates would pay for that in 2-3 hours mate.
 
I understand, and i know it would be worth it, just didnt really want to spend that kind of money at the moment. Are there any places that test them and get all the stats the Vcds give, (apart from Audi obviously) Better still, anyone local that could test it for me :thumbsup:
 
gizm0 said:
I understand, and i know it would be worth it, just didnt really want to spend that kind of money at the moment. Are there any places that test them and get all the stats the Vcds give, (apart from Audi obviously) Better still, anyone local that could test it for me :thumbsup:
Click to expand...

Check the VCDS members list in NHN signature
 
Ah you didnt say you'd disconnected battery yet, lol, good call Mike.

TBH mate which ever garage you go for diag etc will cost you, yes a local vcds member is great, but what happens when you need to do more tests, without being funny people are nice, but when you need it for a prelonged periods & more than once, its a stretch for allot of people as they're busy with family/work etc, of course most are glad to help, but convenience plays a big role here, as I'm sure Mike & all who own will advise & no waiting for results.
 
when car is sat idling open bonnet is engine juddering ?
if yes look down towards left side where alternator is just below alternator is a tensioner is this vibrating back and fourth ?
is yes then the pulley on the end of your alternator is knackered the bearing is seized , this can cause starting problems and the shuddering

the price is 24 quid including vat from tps , but you need a special spline bit to remove it

are you in south yorkshire by any chance ?
 
NHN said:
Ah you didnt say you'd disconnected battery yet, lol, good call Mike.

TBH mate which ever garage you go for diag etc will cost you, yes a local vcds member is great, but what happens when you need to do more tests, without being funny people are nice, but when you need it for a prelonged periods & more than once, its a stretch for allot of people as they're busy with family/work etc, of course most are glad to help, but convenience plays a big role here, as I'm sure Mike & all who own will advise & no waiting for results.
Click to expand...

yeah i understand that, i just cant afford that at the minute so ill have to wait i guess

hollow said:
when car is sat idling open bonnet is engine juddering ?
if yes look down towards left side where alternator is just below alternator is a tensioner is this vibrating back and fourth ?
is yes then the pulley on the end of your alternator is knackered the bearing is seized , this can cause starting problems and the shuddering

the price is 24 quid including vat from tps , but you need a special spline bit to remove it

are you in south yorkshire by any chance ?
Click to expand...

just been out to check that and the pulley looks fine...unfortunatly :( lol

no i'm from b'ham mate
 
NHN said:
TBH mate which ever garage you go for diag etc will cost you, yes a local vcds member is great, but what happens when you need to do more tests, without being funny people are nice, but when you need it for a prelonged periods & more than once, its a stretch for allot of people as they're busy with family/work etc, of course most are glad to help, but convenience plays a big role here, as I'm sure Mike & all who own will advise & no waiting for results.
Click to expand...

Have to agree - in the long run you will find that you need/want to use it more and more.

For a one-off test ask someone by all means but sounds to me like you may need continued VCDS help and diagnosis !
 
dont look at the pulley on the alterator , check the tensioner block just below and to the back of it .

oil in the fuel means that either the tandem pump is knackered or injector seals are
 
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