First big problem - kangarooing!

[Colesy]

My first big problem - kangarooing!

I've read a few posts as to what this could be but thought I'd post up my own problem thread to see if anyone had an idea as to what exactly the problem could be.

The problem has been very intermittent with a random little kangaroo under boost every 3rd or 5th trip. But then the last time I drove it it developed into a prolonged problem lasting several miles all the way home. It seems that when it's hot the S2 starts running very badly when easing off. The worst is when pulling away from a standstill if no/few revs are given the car will kangaroo slightly the revs fall the battery light comes on and it will stall. But if you rev it a little and drop it into gear then it will get going at a splutter and a few jumps but then is fine until changing gear or easing off. I then tried it a few hours after it's prolonged eppie and it was at the same tricks to begin with and then it was suddenly fine.


Things that I've identified that it could be:
Boost Leak
Lambda
MAF
Earth issue

I was thinking that would be safe to rule out a boost leak?! - on the basis that it kangaroo's before any boost is even thought about.

One thing I have also noticed is that the oil pressure seems to be very high, almost going of the scale when idling but dropping back down when on a run and back up high again before stopping. The car is running Homefried but otherwise standard. I need to check my fault codes but don't yet have VAG COM so haven't yet.

Thanks everyone.

[S2central.net]

Opt 1 - Air leak (quite a big one)
Opt 2 - Bad MAF (try a spare)
Opt 3 - knock sensors (faulty or loose)

Air leak can be one or more of numerous places - including throttle bypass valve or WG diaphragm. Most likely is intercooler output o-ring (if equipped) and throttle body hose.

Your oil pressure is fine - pressure will fill the guage on cold idle, then when engine is hot it is much lower pressure. From about 2000rpm onwards with hot engine you should see 4-5 bar oil pressure.

[stevieyid]

if its and aby possible coils? I had the coils go on my ABY and caused the same symptoms. As Pauls says the MAF could be the problem. Try cleaning it, ill clean it on Saturday when we meet, if u can get it there or take the maf off and bring it with you. I have IPA which will give it a good clean

[shark_90]

Throttle position sensor?

[Colesy]

Thanks

Cheers guys I'll have a play with it at the weekend.

I'll bring the MAF with me on Saturday Steve, it's definitely worth a clean.

Thanks

[Colesy]

Update on the problem.

Took the car out for a drive and it was back to normal, missing slightly when idling but nothing major. Took it out again a bit later flicked the sport switch and almost immediately (could have been a coincidence) the idle became rougher and the same problems as before came back. Switched sport off and nothing changed. Took it for a drive to see if I could read into the problems a bit.

Noticed that when pulling away without pressing the throttle it was fine, would happily pull away on the clutch. Only when pressing the throttle did the engine start acting up. Pressing the pedal 1/4-1/2 way down sometimes didn't register for a second or two and then suddenly the revs rose and sustained acceleration was possible. But then when gradually releasing or reducing pressure on the throttle it became jumpy again. So I'm thinking that this could be caused by a poor signal from the TPS.

So does this sound like good evidence to suggest the TPS or could these symptoms be attributed to another possible problem?

Cheers

[S2central.net]

Rough idle is more likely to be an air leak or bad MAF than anything... or injector(s) that are slow/sticky and behaving badly.

I wouldn't worry about coilpacks and knock sensors until its driving smoothly at low load / part throttle.

The TPS is worth checking / swapping with someone too of course.

If you have VAGCOM it would be useful to see Group 0 data on a warm idle - that will help spot anything obviously bad on lambda probe or MAF / air leak.

[Colesy]

Ok for now

I swapped the second hand MAF which I've been using without any issues for a month or so for the old MAF which I removed in a bid to fix an intermittent problem with idling when hot and it seems to be running ok now!

Thanks for the suggestions, I'm pretty sure I'll be back soon with another niggle!

[newsh]

MAF Connector

Next time it happens, just unplug the MAF and plug it back in again, see if it fixes it.