Out of the hutch but a small niggle - Quick bit of advice pls

[Cottis]

Hi all

Despite my best efforts to keep the S2 locked away over the Winter, the inevitable happened and I just had to go for a blast the other day when the sun came out, temps were up and salt had not been down for days.

It turned over perfectly and all was working perfectly as I gently drove a couple of miles down the road letting it get up to temp etc. Went over towards the Barfords, Hempton, Clifton and Aynho (N Oxon), a nice little set of roads that flow and present a good couple of opportunities for the obvious. Boost kicks in and almost immediately the power delivery stops and then restarts quick quickly, almost like ABS system kicking in. Obviously back off and the car performs faultlessly. Boot it again, get past Boost point and around 3800-4000rpm same problem. Very consistent, it happened the first time I hit boost and continued each time I tried. Once it started, if I continued to keep my foot down, the same happens. At no point does the boost recover.

Drove back home normally without problems and it sits there and idles perfectly. My immediate thought was boost leak somewhere and as it will be going in for a service at end of Winter and with me being no mechanic, I just put it back in the garage to be sorted out in a month or so.

Did a bit of reading and before I have it looked at, I want to unplug and plug back in the MAF to see if I have a pin contact problem. I presume it is a toilet roll sizedish cylinder with a plug clipped into it. Can someone help this douche out and point me in the direction of this pls.

Thanks in advance, I included the details above in case anyone thinks the symptoms point to anything specific but having read a few posts on this subject, it seems as usual that it could be a number of things.

[rynaqui]

First would be MAF, boost leak or possibly coil packs/spark plugs are a bit dodgy.

Things that spring to mind, if it turns over correctly it should be one of the above I think, good luck

If it is cutting boost always at the same point (4000rpm +/-), that should indicate MAF sensor.

EDIT: This is the MAF:

http://www.wyldthingz.net/site_photos/matt_parts/968_maf.jpg

[ericd]

you've described symptoms that many have described here over the years, you've more than likely got a boost leak, use it in the search box and you'll find many similar issues described over the years, could be as simple as tightening some of the hoses as it sound as if its sat a bit before recent use, again have a quick search, there's plenty of easy solutions that may fix it even if you're not too hands-on, a service will generally not fix it unless you've a very persistent mechanic who's happy to chase his way round the pipework

hth

[Cottis]

Perfect, thanks for that. Gut feeling is the MAF, I will have a play.

[ericd]

i'm sure there a few forum members down your way who could have a quick check over it for you if you could take it to somebody local from the forum, I always found them very friendly anytime I was "down south..."

[Monkeymagic]

exactly what we hae all suffered with bost leaks. I fixed a very rotten oil breather got full boost and over the next three days blew hose after hose. Old age had got to most of the hise and they were tearing under the pressure.

[Cottis]

Thanks Eric, was also my initial thought when I read a number of past posts on the same issue. Fortunately my mechanic worked for Audi from the mid 80's to mid 90's. He quite enjoys working on the Audis that I have had down the years but this one might test him more than most ha ha. Just thought I would double check the MAF first as this is something I can do but getting the right gear and then performing the various tests is not something I should be trusted with boost wise. Should have said I quickly checked all Juby Clips etc and various visible or accessible pipes that I could see. All seem to be in order but I guess even a tiny opening/crack could prevent all types of problem with forced induction. Fingers crossed, thanks for your advice.

[Ian Simmonds]

I chased those symptoms around the car for literally hundreds of pounds until I changed the coil packs... HTH
Ian

[Cottis]

Hi Monkey, you have the Black 3b, I nearly went for that a while back. Hope it is a good one. I really wanted it, especially on the Bolero's but end up coming up trumps.

I went for a fully restored 3b myself in really fine fettle, so hoping the various pipework (which looks very new) isnt the problem. Will report back when I find out what the issue is.

Cheers guys. Amazing how many people just jump in to offer help etc.

[prj]

First would be MAF

Disagree.

If it is cutting boost always at the same point (4000rpm +/-), that should indicate MAF sensor.

With this as well.

If the MAF sensor is gone it'll drive like crap down low too and idle will be bad.
If it's MAF connector it'll be on and off, not constant. Meaning re-starting the car will resume normal operation at least for a bit of time, until the connector messes up and it goes into limp mode again.

Could be fuel cut the first time, then it going into limp mode and keep cutting out due to a boost leak. Limp mode fuel cut limiter is lower.

If it cuts so much that there is no power at all and abruptly, it's deffo fuel cut which is most likely caused by a blown off or split hose.

[ericd]

Thanks Eric, was also my initial thought when I read a number of past posts on the same issue. Fortunately my mechanic worked for Audi from the mid 80's to mid 90's. He quite enjoys working on the Audis that I have had down the years but this one might test him more than most ha ha. Just thought I would double check the MAF first as this is something I can do but getting the right gear and then performing the various tests is not something I should be trusted with boost wise. Should have said I quickly checked all Juby Clips etc and various visible or accessible pipes that I could see. All seem to be in order but I guess even a tiny opening/crack could prevent all types of problem with forced induction. Fingers crossed, thanks for your advice.

no probs, again if you have somebody local and they have or can do a pressure/leak test vag-com errors (if any) then it may save your hours of trouble and then you could move onto the plethora of other items that may be causing your problem



n.b.

for the bigger hoses a lot of them split under the hose clip so worth double checking

[rj scotty]

I'm giving serious consideration to hard wiring the loom straight into the MAF and getting rid of the connector completely

[prj]

I'm giving serious consideration to hard wiring the loom straight into the MAF and getting rid of the connector completely

I wouldn't do that.

[rj scotty]

Do you know of another solution to fix that connector for good?

[prj]

Do you know of another solution to fix that connector for good?

RS4 MAF with it's connector...
Or just buy new inserts for it and re-pin it, or buy a whole new connector.