Running Issues.

[europeanme]

There appears to be a few owners with running issues, and after searching the forum, i have decided to post my problem...

My avant is running like a bag of "you know what!"....
It has been homefried, new boost hoses and boost checked..it is currently on it's own adgenda...it runs ok then runs badly...more badly than ok.....

it hesitates, can even stall even in traffic then start straight away with no problems and be ok after....
the over boost kicks in so often now....even at 0.8 bar... like I mentioned it has it's good days and bad....it appears to be overfueling (black smoke) on WOT...if it will let me...(over boost kicking in... )

it is starting to really pee me off.....does anyone recognise these faults and have any tips/advice how it was cured....

cheers
Mike

[Flat on my back]

.

Start up and idling is ok? Hot and cold situations?

Sounds like MAF related...pulled the codes?

[Fat Audi 80]

You need to pull the codes first and foremost and go from there...

HTH

Cheers,

Steve.

[GazzaG60]

amazing the number of issues there are with cars and nobody bothers with an AF gauge hardly ever. they were almost standard in the G60 world.

a narrowband AF guage will tell you when the o2 is working properly with its fluctuation
it will show you when you go what the hit and hold of fueling.
it will help detect bad probe/signal wire/earth issues in this area.
it may also help with water temp based issues as these are part of the process of closed/open loop.

they wire in easily. live earth and signal. signal needs to be tapped into the existing probe signal wire. earth to where the probe earths to so that the gauge replicates the actual signals.

[Quattro Dan.]

I am having the same symptoms, Gazza can you recommend a gauge?

[GazzaG60]

i used a cheap summit racing gauge. still have it... i think. ill see tonight if i do. you are welcome to borrow it. if you dont want to permanently wire it in thats fine. ive done this before on subarus just tape it to the dash for a bit. usially the frequency of issues is under a day or a week. things liek poor engine mounts can tug at the wires causing intermittent issues.

i can understand not wanting to fit extra gauges to these cars. the corrado had a cassette box that could be replaced with a factory panel for 2 gauges

http://www.summitracing.com/parts/SUM-G2986/

thats what i have 25 dollars. let me know if oyu want me to try and find what i have. when its fitted let us know what it does.

the genral is.

when car started its in warmup so. lights start at maybe 2 and 3 then rise. after 2 mins or so the guage lights go from rich to lean. thats the probe doing its job-finding stoich. when you mash the throttle they go 1 or 2 from top and hold. thats going to map. when the probe does it drops to lean. the ecu thiniks its lean so puts more fuel in. it still says lean so more fuel. you end up with a chugging car that hardly runs. this is usally after a few mins or so. you feel it get worse too. a bad earth is a similar reading. its a narrow band sensor. this means to us it covers a narrow voltage range but accurately.

a gauge works best but a v meter set to 0-1v will do the same. its should fluctuate then hit and hold. much better using a light sequence though.

[GazzaG60]

if you can pull the codes it may help too. theres lots of guys on here who can help with codes. all depends on how trustworthy the codes are.

probly a good first stage. these types of issue are commonplace on FI cars with vag wiring. seems the japs are better at that side of it.

[europeanme]

Start up and idling is ok? Hot and cold situations?

Sounds like MAF related...pulled the codes?

Starts on the button.....hot can be only a bit longer but never every been a worry..I am talking an extra second or 2 when it's hot....

got it vag-com'd by Ben (shark90) tuesday and the usual engine speed error and that was it!!!.... I was expecting, and hoping so I could get to the bottom of the problems, there would be a few errors...but nothing out of the ordinary....

one thing I have noitced once it has been started it stalls after about a minute or 2...if I come to a stop..which I normally do....leaving home for work...at the top of the road or leaving work waiting to get on the main road.....

Hey Dan looks like we are in the same boat.....

[audiman]

If you are getting over boost type issues then i would expect it to log an error in the ECU. I would start with a pressure test and go from there. Black smoke is way too much fuel, sounds like a massive leak or dodgy MAF. Dodgy MAF can also induce the overboost condition.

[europeanme]

If you are getting over boost type issues then i would expect it to log an error in the ECU. I would start with a pressure test and go from there. Black smoke is way too much fuel, sounds like a massive leak or dodgy MAF. Dodgy MAF can also induce the overboost condition.

wouldn't having a dodgy MAF show an error code??...

when you say leak...what exactly would be leaking??...

Would dodgy cats/lamda cause these sort of problems??....

[ericd]

Starts on the button.....hot can be only a bit longer but never every been a worry..I am talking an extra second or 2 when it's hot....

got it vag-com'd by Ben (shark90) tuesday and the usual engine speed error and that was it!!!.... I was expecting, and hoping so I could get to the bottom of the problems, there would be a few errors...but nothing out of the ordinary....

one thing I have noitced once it has been started it stalls after about a minute or 2...if I come to a stop..which I normally do....leaving home for work...at the top of the road or leaving work waiting to get on the main road.....

Hey Dan looks like we are in the same boat.....

you checked the condition of isv ?, also check that you can get WOT, cable isn't slipping and properly connected and that the TPS is working as it should

[audiman]

wouldn't having a dodgy MAF show an error code??...

when you say leak...what exactly would be leaking??...

Would dodgy cats/lamda cause these sort of problems??....

1) Not always - if the voltage is still within range, but fixed at say WOT readings then ECU doesnt think anything is wrong with it. ECU isnt clever enough.
2) Hole in boost pipe/hoses - pressure test needed
3) No, a dead lambda wouldnt cause this, black smoke means severe overfuelling lambda only operates at idle or part throttle and controls mixture to a certain degree.

[europeanme]

I had the system boost checked the other week....although the PCV and more hoses have been added.....aaahhh that might be an option...I'd be stunned but hey you never know....

[europeanme]

you checked the condition of isv ?, also check that you can get WOT, cable isn't slipping and properly connected and that the TPS is working as it should

I did clean the ISV last year...but with it not working it wouldn't idle at all...

TPS???....trade part specialists??...

What cable would be slipping....

sorry for all the dumbo questions....it's been a long week....

[Flat on my back]

.

TPS... Throttle Position Sensor.

Needs to be acccurately set to ensure ecu knows how much you plant your foot and when WOT is needed.

Its a variable resistor that converts the signal back to the ecu.