Audi UR Quattro Engine Management Light & Hesitation

[tiny_dancer]

Hi,

I've recently had my MB UR Quattro re-commisioned and everything is great except a minor hesitation and illuminating engine management light on acceleration.

Doesn't happen all the time, just intermittently.

Has had the full works, all fluids changed, cambelt, leads, plugs, fuel etc. It was stored for last 9 years...

Any ideas?

Thanks in advance.

[SPEN555]

The ECU is in the drivers footwell just below the front window pillar. Water can run down and get onto the ECU and create havoc. When I had my Ur I wrapped a plastic carrier bag around it to stop any water getting on it.

Just a thought.

Also, if you have not used it for 9 years there maybe a bad connection somewhere.

[Yertis]

tiny_dancer said:

Hi,

I've recently had my MB UR Quattro re-commisioned and everything is great except a minor hesitation and illuminating engine management light on acceleration.

Doesn't happen all the time, just intermittently.

Has had the full works, all fluids changed, cambelt, leads, plugs, fuel etc. It was stored for last 9 years...

Any ideas?

Thanks in advance.

I've got an MB. Start by remembering that although it feels so modern it's thirty years old now. That said, I think that although they're probably the most reliable Quattro they're also the trickiest when they go wrong, having a unique engine management system. I know you've said "fuel" – was that simply putting fresh fuel in, or going through the system and replacing filters etc? A specific problem on these is the metering head itself – the internal seals degrade (apparently). Or, it could be the ignition amplifier / coil (that's what it sounds like to me actually). Honestly, there are so many points of failure on these things. Mine was hesitating on accelerating, but only when warm. Turned out a temp sender was a bit loose, the ecu thought the engine was still cold and was firing the cold-start injector every time I put my foot down. Things like injector seals going hard also affect performance – I had to change those too, cyl#5 wasn't much fun.

Who recommissioned it? I'll be honest – there are only three people I'd trust with mine. Sorry I can't be more help but it could be so many things.

[bluesmoke2stroke]

Can't help with diagnosis but can recommend this garage
www.keithedwardsmotors.com/

[tiny_dancer]

Great thanks, I will have a check through the car on the above.