can anyone help with this fault???

[iain,henderson]

Can any body help me with this problem on my car, has anybody had the same symptoms. I have a b7 RS4 and when trying to start the car sometimes it has taken a while to start, that's part of the problem. Then when I have been going around 40mph in say 4th gear taken my foot off the accelerator and back on again gently/normally I get a jolt in the car, another part of the problem. The last part has been when I have approached a roundabout put my foot on the clutch the car has stalled. My car has been at Audi for 8 days now and they can't find a fault, the computer in the car isn't bringing up any problems. I thought it might have been the plugs but they think it is link to the fuel pressure dropping, they have contact HQ to see if any other RS4 has had the same problems and they haven't any thoughts???
Thanks
Iain

[toyneg]

Clutch switch? I know that a faulty clutch switch can cause the car not to start easily - sure someone more technical than me will be along shortly to add some advice

[rocket1]

has your cruise control been working ok?? that can point to a faulty clutch switch too. there well known for failing and at £18 and 5 minutes work i would change it anyway. good luck!

[iain,henderson]

The clutch starter and the cruise control works thanks, it seems to be related to the fuel being starved as the plugs were quite white in colour. The car will turn over ok but it wont always start as normal, it keeps turning over. Cruise control seems to be working, spoke to Audi again at lunch and they took the car out and the car kept lunged when you took your foot off the accelerator and put it back on again, it seems to do it over 2500 revs and when the oil temp is at 90 and it keeps cutting out as if the fuel is not getting through. It had a new fuel filter last year and the car has only covered 5k, air filter is ok and we don't think it is the engine more like a sensor but which one??? Any thoughts would be great.
thanks

[coffey555]

Sounds like the problem I was having a few months ago.
My car would run on when lifting off the throttle, gear changes were not smooth and the car would idle erratically when in neutral with the clutch fully depressed.

It never actually stalled on me though but would sometimes turn over a few times before it would start.

I ran a full scan which showed up no error codes so completely stuck I phoned up the guy that looks after my car.

Straight away he said it was probably excessive carbon build up on the inlet valves. He had seen the same problem on a few Audi V10 engines.

And sure enough after it was given a proper carbon clean it ran perfectly again afterwards.

It was pointed out that there might have been a vacuum leak from the one way valve under the inlet valve which may have been causing the issue as this was the only other thing that was disturbed or changed during the cleaning process.

My car had done 120,000 miles by that point so was probably as bad as it was ever going to be.

My plugs have always looked white when I have removed them apart from the one that was being used by a leaky injector.

Hope you get it fixed.

[iain,henderson]

Ok well I got it fixed and the problem was the petrol pump for the fuel tank, it kept losing pressure. It seems to be the first time that Audi have had this problem on an RS4 but 2 weeks later and an £800 bill sorted!
Thanks for the help with this one guys.

[Rick_RS4]

wow, how much was the pump

[Bladerider]

wowzers !!

Surely its just a Bosch 044 which are about £100 online or £200 from a place like Demon Thieves.

Cant take more than an hour to fit plus an hour fault finding, surprised its over £500 to be honest.

J.

[iain,henderson]

yeah I don't think the pump cost that much, it was trying to find the problem that cost in labour and a couple of other parts they tried as well. I did get some discounts on the parts and the labour charge was discounted but I think they were well over 10 hours on the car. It did have them stumped and nobody has seemed to have this problem before in Audi. The car does have full Audi history so I wanted to keep it up, I did have another guy in mind if they couldn't solve it!!