1.8Tfsi fueling issue

mickdw

My A5 1.8T has developed an intermittant fault in that it sometimes continues to drive on alittle after coming off the throttle. I can just feel it continue to put in fuel and then if left maybe 10 seconds, you can feel it drop back to zero fueling. The trip computer also corresponds with this. When working correctly, the computer shows fuel feed at zero pretty quickly after coming off throttle but when fault occurs, the computer shows the fuel still being used.
The throttle body has been cleaned but this made no difference. I have vagcom so if anyone can give me a few tips as to what to check.

There are no issues with idle speed or anything like that and when I come to a stop, it doesnt hold a high rev even if it had been driving itself on right up to when I clutch to stop. It quite a slight issue at this time but I want to get to the bottom of it.

Nissan doctor

It may be an idle control issue too. did you get any fauld codes yet?

mickdw

I checked a few weeks ago and there were no faults but it was very very occasional at that time. I must have a look again one of the days.

If no fault showing, any ideas of parameters I could log to try to trace the issue.

Rob32

Could try checking the throttle position, make sure that the pedal hasnt gone faulty and is taking a second to realise youve released it.

crosshair1

Is cruise control working ok?
At a guess a faulty clutch switch and this doesnt leave a fault code.
Its in block values if you have vcds, worth checking anyways

mickdw

Cruise is working fine. Its not fully driving on of its own accord, just a slight feeling of power input.

lafors

Not sure if the 1.8TFSI has one but......
Could be way off the mark but that's a symptom I had on my old 2.0TFSI when the PCV went on me. Had a few other symptoms though, rough idle, felt slightly down on power too.
Might be worth a look? Easy to check, cheap to fix.

spiggotpaddy

Did you use your vag-com to do a throttle body alignment after you cleaned the TB?

mickdw

I did as I had the throttle body off the car completely when changing water pump recently.
This issue existed before that work though but I hope to have a good look tomorrow again if dry. Might do both pedal adaptation and throttle body again?

mickdw

I did the throttle body adaptation again and after 1 day, the intermittant issue hasnt come back so maybe it has cured it! I hope so.