Engine cutting out why?

[orsum]

So continuing with the shakedown of my S2 Coupe ABY. Yesterday something strange happened.

Did about 100km and the car was fine. Car was stopped for about one hour to have the wheel alignment done.

Started no problem, pulled away slowly, stopped at a junction, waiting to pull away from a junction, as I was pulling away I put my foot down the car got to about 2500rpm and it just felt like there was a big jerk total loss of power. Took my foot of the accelerator and then gently pressed the accelerator a small way down the car was not accelerating more like cruising normal.
So under light acceleration and the car ran smooth.

Took the car to and Audi dealer and asked for the Tech to go for a drive. The car did the same. Tech said typical coil pack issue. Replace coil packs and problem should go away.

So I left Audi thinking no problem have a conversion kit at home to suit the R8 coilpack upgrade. I left Audi and did about 30KM stopped at a friends to collect a couple of mono blocks for my sound system and had a coffee.
About one hour later I started the car drove off and hey presto no more problems running smooth.

All the way home no problems on the drive home I pushed the car to 240kph it ran very good.

Its still running good.

Anybody wish to put a possible cause to what happened.

No codes taken Audi said they had a problem with getting the right connector!!!

[mike74]

When I had a coil go bad a few years ago it was very intermittent. It would be fine all the way into work in the morning and when I went to leave work at night it would run on 4 cylinders all the way home. Then it was ok for a few days then back to playing up.
it could easily be a coil starting to play up

[orsum]

This was not one coil pack it felt like all of them at the same time.

[Rikki Kitto]

If the cut is violent just as you come on boost it is a boost leak do a leak test and should be fine once fixed, there is good info on here just do a search for boost leak test

[orsum]

If its a boost leak why did it go away? A hole is a hole

I will check for a boost leak.

[Rikki Kitto]

They are very mysterious things I've had many over the years and sometimes they kick in sometimes they don't but they are still lurking in the background

[rynaqui]

That can also be the MAF buddy. I just got a boost cut yesterday and idle has been very off recently so basically got a lot of maintenance to do on it. New plugs gapped correctly, clean up the MAF connection and a good clean up of all the sensors and see what happens. Then move onto the coils from there

[orsum]

I purchased the coil conversion kit and new R8 coil packs several months ago for my planned upgrade, I think I am just going to change them now anyway.

Don't like touching things that don't like being touched

[rynaqui]

Yes that's a good place to start from

[Rikki Kitto]

Someone advised a boost leak test should be done every oil change or 6 months, seems like a good idea

[alev8]

As stated , it sounds like a MAF problem or more probably the Coil packs...
since you have the conversion kit, just install it. it won´t do you any harm...
Normally when we have a maf issue, it messes up the idle also.

[orsum]

Idle was as smooth as a baby’s bum, even driving with very little throttle car engine was smooth.

Only when putting foot did it jerk.

Then it disappeared after a couple of stops and turning the car off for an hour at each stop. After the last stop the car ran well.

[Rikki Kitto]

If the car drives fine without turbo coming in it's a boost leak for sure I drove mine for weeks like this to avoid getting chucked through the windscreen until I could be bothered to chase the leak

[newsh]

Try cleaning the MAF connection first

[newsh]

Just re-read this, 99% certain it's the MAF or MAF connector. If you could pull codes you would get adaptation error code.

If it was a boost leak it would not go away.

Next time it happens, pull the MAF connector on and off a few times and see if it fixes it.

http://www.s2forum.com/forum/showthread.php?t=24544