s3 cold idle

[V8Sam]

hello guys

the Audi seems to have a very rough cold idle when first started, sounds like it missf ires and wants to die, (it never does just stutters to around 4-500rpm then pops back up to the normal 1200ish rpm cold idle)

this last for a few mins untill its driven a little while, then it runs flawless.

seems to smell a bit of petrol as well, possibly running rich? (vagcom does throw up a fuel system to rich message) but its been doing that before this started.

coolant temp sensor?

 

[<tuffty/>]

Clues are there mate...

That code comes up when the ECU can no longer take fuel out... poorly MAF, blocked FPR etc can cause this code...fix the issue causing the code then go from there

On cold start there is no real lambda control... if the fuelling is overly rich from a blocked FPR for example then it will be choking on an over rich mixture until its warmed up a bit...

<tuffty/>

 

[V8Sam]

checked FPR,

was clean as a whistle.

not sure if its over fuelling continually was managing to hit 39.5 mpg on a run the other day..which isnt half bad.

does go into 5psi mode whilst on cruise control around 75mph, then it comes back out of that and runs fine again, then goes back into it..like it cant make its mind up what to do.

worth replacing the MAF? anything else?

 

[<tuffty/>]

No other codes?

<tuffty/>

 

[V8Sam]

Not checked in a while.

Was only that one at the time.

Will check again later and let you know.