Only getting spring boost

[rynaqui]

After a while of driving (It is always random on which time it starts to produce only .4 bar boost), boost is cut to .4 bar. Now the thing is I didn't notice any problems while running normally. It is boosting correctly to 1.7-1.9 bar thereabouts and the power is there as it was before.

I opened the bonnet today and found that there was a bit of fuel around the injectors and it makes sense as I changed them and forgot to change the injector seats when I replaced them . Could it be that it is occasionally running lean and the engine is going to spring boost as safety or is there something else I should be looking for? Have ordered the injector seats from Audi hoping they'll be here this week and that it will sort out my problem. Otherwise all is well and the car is running great

[Thuppu]

Make a boost leak test and see where it bubbles.

[rynaqui]

What's the correct way of doing the boost leak test? Through the MAF hose, about 1 bar?

[Rusty]

Unplug your mfts and see if that cures it or check for faults esp a g40 intermittent fault.

[rynaqui]

Think it's time I invested in vag-com. So do I need an OBD 1 cable and then just vag-com for the laptop? So then I can get cracking

[UrS4boy]

S2 and RS2 3B, ABY and ADU boost leak testing

What's the correct way of doing the boost leak test? Through the MAF hose, about 1 bar?

That you have to ask after I have posted and reposted the link to the post below is disappointing on many levels:

http://www.s2forum.com/forum/showthread.php?t=63974&highlight=boost+leak+testing+S2

[Rusty]

Yeah, Ryan, we're not angry; just disappointed

[rynaqui]

Sorry to disapoint you guys but I am not so familiar with boost leaks

I need to get this sorted, went out yesterday for the evening and the car was ok apart from a bad idle when starting up once from home, then from the petrol pump..it didn't always do it but sometimes I had a really lumpy idle to the point where it turned off once, then after a while it would be ok. Need the vag-com to arrive so that I can get an idea what's up and find time to do a boost-leak test

[geneandbolly]

see my thread on "S6 Boost Blues" for details on the n75 valve - maybe your's is gubbed too?!

[UrS4boy]

Sorry to disapoint you guys but I am not so familiar with boost leaks

Sure, but at least you could be familiar with this (with "Any date"):

http://www.s2forum.com/forum/search.php

[rynaqui]

Sure, but at least you could be familiar with this (with "Any date"):

http://www.s2forum.com/forum/search.php

You learn something new every day, does the "any date" option make a difference when searching? Just waiting for cable to arrive so I can get some codes read

[UrS4boy]

You learn something new every day, does the "any date" option make a difference when searching? Just waiting for cable to arrive so I can get some codes read

The default on advanced search is "6 months ago" (and sooner). "Any date" searches all the posts in the history of the S2Forum. Makes a big difference. Anytime you have an issue, you should always use that search to find out what has been found out about it before. Makes life easier.

[rynaqui]

The default on advanced search is "6 months ago" (and sooner). "Any date" searches all the posts in the history of the S2Forum. Makes a big difference. Anytime you have an issue, you should always use that search to find out what has been found out about it before. Makes life easier.

I didn't know that, thanks a lot Dave

[rynaqui]

Got a video of something else it's started doing, it has a rough idle about a minute or so after start up, any ideas? Unplugged MFTS and still did the same thing, MAF connector cleaned and no change. Any ideas? It's died on me once in traffic.

During the video you start to see the idle playing up, that is about a minute after start up, it doesn't do it all the time though

Might pop by to the office and try see if I can get vag-com running, will wait for traffic to clear up a bit first though

https://www.youtube.com/watch?v=jjJehrb0s_E&list=UUaS5YLGlb-N0jo4QWZZSD0A

[UrS4boy]

N122/N127 Power Output Stage (POS) info

Got a video of something else it's started doing, it has a rough idle about a minute or so after start up, any ideas?

You have an ignition miss. Assuming your plugs and coil-to-plug boots are in good shape, it is probably a POS channel is dieing.

Click on the N122/N127 label in this diagram and look for the POS diagnostic link in the POS info post:

http://members.shaw.ca/speedtek/UrS%20Engine%20Bay%20Device%20Map.html