Remind me!

**S2central.net** · 25 July 2007, 23:17

SURE you haven't got an air leak ?

Reset the ECU to clear the faults - maybe thats some old faults in memory...

Fresh lambda is always good if its due a change.

**GT500** · 26 July 2007, 00:15

I am just sorting mine at the mo,
same codes, but not the boost exceeded,
I have a new Lambda on as well!!
NOt had them back since I upped the spring tension on my HKS bov, must have been sucking some air.
I am thinking they throw the two codes if you have some unmetered air in there...

**Crawford_S2** · 26 July 2007, 17:51

Originally posted by S2central.net

SURE you haven't got an air leak ?

Reset the ECU to clear the faults - maybe thats some old faults in memory...

Fresh lambda is always good if its due a change.

Seriously, i am pretty sure there is no air leak. Done the inlet side recently and it held fine, drove over the mitivac so can't do the small vacumm lines but a lot of them are new. Thing is the boost comes in at WOT and the gauge is steady as a rock holding boost, no flicker or dips. The boost cut happened when i pulled out a junction, car was warm, 3/4 throttle in first and it hesitates like it was missfiring then off it went. Changed to second at 1/2 throttle, making about 10psi ish so not full boost and that horrible cut reared its head, backed of and power was restored.

Went back, cleared the codes again, did loads of WOT runs up and down the bypass and nothing, good as gold

Got up this morning and after it warmed up had a slight hesitation on very light throttle but no cut. Pulled the codes before i fitted the new lambda and just one

561 Mixture adaption

Shot on the lambda and going to see how it goes, got it from GSF 50 quid, pattern which i am usually wary of but can't hurt.

Oh yeah and did the fuel pressure, had no residual pressure which i was a bit confused about but wound the gauge to 4 bar on turnover

Couldn't find a fitting to fit the return so can't tell if it drops off when running but it good pressure to start with.

Guessing a good maf will be my next try as it also adapts mixture. I understand the lambda and Maf only have an influence on mixture at part throttle and don't get a say at WOT anyone confirm this?

**Crawford_S2** · 31 July 2007, 16:09

Got a Known good MAF on it after pulled 537 the other night. Going to run it for a few days and if that sorts it will have to fork out for my own.

**GT500** · 31 July 2007, 16:55

Originally posted by Crawford_S2

Got a Known good MAF on it after pulled 537 the other night. Going to run it for a few days and if that sorts it will have to fork out for my own.

Let us know how you get on, as i have still got 561!!!

**S2central.net** · 31 July 2007, 23:52

Could be MAf alright... Let us know how you get on with the spare Crof !

My bloody cutout came-back as well yesterday, despite convincing myself that I had fixed a minor boost leak on mine. I have a spare MAF that I must fit after resetting the ECU. I mean it is 14 yr old so its unfair to complain too much - except about the price for a shiny new one !

**Crawford_S2** · 1 August 2007, 00:38

Tell me about it paul, Vagparts can get em at a not too massive price but i thought i would try my local bosch place to see what they could do. £261+vat+130 surcharge on the old unit

The bloke was fairly straight and said i would get it cheaper just about anywhere else but it is mental what they wanted and they wanted the old one back

Will keep you all posted, got to do more miles to make sure but plan to pull the codes again by the end of the week and if they are gone, get one ordered.

Oh yeah, Paul, the car a borrowed the MAF off is the quattro my mate has been trying to sort out for ages. He has checked all the pin outs on the ecu and been through the pheckin thing with a fine tooth tester. Says he needs to get you the ecu for testing, can you pm your contact details again so he can sort it, he isn't much of a net head.

Ta

Crawf

**Crawford_S2** · 2 August 2007, 00:02

Right code reader was out again tonight and hoooooooray, only one code! And it was the engine speed one that is always there

So i now need to get hold of a good new MAF as soon as possible cos the one i borrowed needs to go back on the doner car before the owner notices its gone- Bad times!

But on the plus side i think i have finally found my intermitent fault that has been driving me mad since the goodwood meet at least- Good times

On a side note my old MAF looked ok, had a good bath in IPA recently which seemed to help briefly, but it turns out it is degrading and not up to the job any more. My mate looked at me like i was mad when i told him about the IPA bath thing as he is a very respected and experienced mechanic and has always been of the opinion that if it isn't right, replace it. I however am now having to eat humble pie after swearing by my cleaning antics and telling him it was all worth the grief. Turns out he was right, so the moral to the story is if it is phecked get a new one. I spent ages pheckin about cleaning, checking and fannying cos i didn't want to fork out for one but i am now anyway

This has been a mare of a fault to track down but if you do get these codes come up and the cut comes in at part not full throttle, a lambda and maf seems to sort it, well it sorted mine anyway

**S2central.net** · 2 August 2007, 00:15

You been watchin that Justin Collins bloke on C4 waayyyyy too much

Glad you are sorted now... I've never been much of a believer in the 'MAFBAF' approach but I guess it can be used to renew a particularly dirty one and extend its life.

I wish someone, somewhere had a test rig for MAFs - not just for us - it must be a general purpose requirement to scientifically test the output from a MAF... All it would is a datasheet from the manufacturer that shows what o/p voltage to expect across a range of airflow rates (normalised for ambient blah blah blah).

Seems to me that the folk who can measure the flow rates on cylinder heads (before and after port jobs) should have the smarts to do it. Its the sort of thing that a Dave Walker could knock up in his shed in a day.

It would also allow the flow rate thru various airboxes, filters and such to be objectively measured.

You know how you get the confidence from an ASNU cleaning and testing machine for fuel injectors - think of the same result from another gizmo that could properly test your MAF for sanity !

Paul

**Crawford_S2** · 2 August 2007, 01:01

sounds brill idea mate, but get the feeling if they made it to a test rig then chances are they are fecked. Now convinced a lot of the issues i have had somehow go back to this dodgy MAF. It just seems to only misbehave at certain set of specific circumstances and the deterioration has been so slow, i would have expected it to give up altogether at some point.

Its no secret that the later type VAG MAFs are rubbish and are often the cause of all sorts of running issues. For a time at my mates garage, every time they say a 1.8t golf it was in for a MAF, so much so he keeps one in stock! So it isn't that unreasonable to have to replace then on what is after all, at best, 12 year old cars i guess

What would be cool is if we could find a maf that worked on the S2 from another motor that isn't an arm and a leg:mischeif: Thought someone on here is running a beamer one, not sure though

**S2central.net** · 2 August 2007, 09:02

Thats the thing Crof - with a test rig it would be pretty easy to find a suitable replacement device - either for standard S2/RS2 applications or big turbo upgrades that can make use of a MAF with higher dynamic range...

**Crawford_S2** · 2 August 2007, 09:25

Right then so who will build one, i would but a) i ain't all that clued on electronics and b) kind of got to do another two years of this degree and it doesn't half eat in to your tinker time! Maybe i will try and get some figures out of the new and old one. one day

**Briggsy** · 8 August 2007, 20:33

"I understand the lambda and Maf only have an influence on mixture at part throttle and don't get a say at WOT anyone confirm this?"

can anyone confirm this??

jose.

**Crawford_S2** · 9 August 2007, 15:51

Ok new MAF is on and still going strong, wish i had put my hand i my pocket ages ago! So if you can get a loan MAF when you are having these fault issues its well worth it!

Remind me!

Remind me!

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