Audi cutting out at lights and idling badly

[Guvnar]

Hi

I was wondering if anyone can help me with a problem I have recently been having with my Audi A4 B5.

Recently when I come to traffic lights or any roundabouts my engine seems to idle very badly as its starved of fuel. Most of the time the engine completely cuts out resulting in me to having to start the car up again.

When I start the car in the morning it is fine and drives absolutely normal for about 10 minutes. Soon as my temp coolant reaches up half way on my gauge, that's when the cutting out of the engine and really bad idle of the car starts.

The few things I have had done to rectify this problem
Brand new throttle body replaced & adapted with Vag Com
Upper breather pipes removed, cleaned and replaced
Vacuum pipes replaced as some were damaged.
Coolant fully drained and replaced and also had the coolant thermostat replaced.

Lambda sensor replaced - Genuine Audi replacement.

Air Mass flow sensor replaced with a new Hitachi replacement.

What I have also noticed is that when I drive my car in 2nd gear and take the revs up to 5000rpm the car judders and jerks and wont go any higher in the revs. It only seems to do this in the 2nd gear?

Any help would be appreciated on helping me diagnose this problem

 

Regards

Guv
 

[Audi Owners Club.]

Hi Guv

Maybe worth checking the Coolant Temperature Sensor (CTS) as these can fail and lead to the symptoms you are describing

Cheers   Trevor

[luggs2008]

Hi,

I had similar problems too, turned out to be the mass air flow sensor, I know you said you changed it but i have had new parts go faulty before, you may of tried this before but when you start the car and it warms up and it starts cutting out again, try disconnecting the multi plug to the mass air flow sensor and try starting the car it should fire up and stay running (all be it at a reduced performance) but it is a indication that the maf sensor is on its way out. also the coolant temperature sensor could be faulty, on some engines they have only one coolant temp sensor some have two, if yours is with two coolant temp sensors, one is for the temp gauges on the dash clock, and the other sensor controlls the fuel injection, from my experience check what colour the sensors are and make sure (if it is faulty) to get the most recent one( i think is green) if your car has only the one temp sensor i think it controls temp gauges and fuel injection.