engine trouble

[tommyt2]

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Hi everyone was sitting talking to a guy at my local shop, tonight for about 2 hours the engine temp wasnt fully warmed up but had been previous to having the chat.I started the car and just as i was leaving he said that sounds nice give it a rev so i did reved it to about 3500 or so and the cars engine became eratic for a few seconds, like as if it was missing or overfuelling the revs went down to 800 for a second or so then back to 900 to normal, but the car kinda shuddered like as if twas running on a cyclinder less or the waste gate was stuck on the turbo. I drove it then and it was fine and gave it a rev afterwards and its fine just a little worried any body got any idea or experencied this the car is a 2.5tdi 180 bhp quattro a4 b6.

 

[arthurfuxake]

Sound like the ECU was having difficulty calculating the air/fuel ratio to use. The 3500 rev at standstill was unexpected, and it was in the process of adjusting the fuel mixture to be rich due to the engine being cold. When it got the high revs, it had to recalculate the fuel mixture and probably just experienced a moment or two's indecision, which caused the rough idle. It's not that difficult to confuse the ECU for a second or 2 just by doing something very unexpected, so I'd not worry about it too much. If it happens regularly during "normal" driving, then start to worry.

 

[tommyt2]

thanks for the peace of mindWhile on my lunch break got a diagnostic check done,and nothing was there just 0 faults found for which im glad.My car has a serious remap done by turbo tech in Bray Co:Wicklow in ireland well actually more like 10 remaps i always wanted more power each time so im definately 50 bhp more than she was,as the same map we used had been tailored on the rollers by es tuning big audi tuners in Norway so we then modified that and there map had given a 45 bhp increase.,Getting it rolling roaded in about 2 wks hopefully at track day performance using his dyna pack rollers would have done it sooner only he needed software upgrade as the a4 is torsen quattro and not haldex but expecting to see 225 bhp maybe more .... anyone thinking of getting a good remap should look up www.turbotech.ie or if you have money to burn www.estuning.no my car no longer has issues with lag below 2000rpm power from 1200rpm

 

[VennyQuattro]

SNIP 'as the a4 is torsen quattro and not haldex '

excuse my ignorance, but what does this mean?

 

[tommyt2]

i think its with haldex the car is front wheel drive until the computer tells it to send power to the back all electrically where as the original audi from years ago and the a4 b6 use torsen which is pure mechanical all 4 wheels always hope this right......

 

[arthurfuxake]

Correct