Overboost protection, please help...!

[newsh]

I meant the little blue and white valve in the PCV system, it sits behind the cyl head and joins two pipes of different sizes, but it looks like you already replaced it

[LHD_Kid]

Yes, replaced that, along with most of the PCV system (including a rather snazzy little aluminium fitting.......)
OK, so.... had a busy morning...
Took out the APS, generally wiggled it, blew it, was clean as a whistle inside, but fiddled nevertheless... no difference...
1000 grit wet and dry to MAF plug male and female parts, cleaner spray and replaced... no difference...
I have backed off the wastegate spring by one quarter of a turn... no difference...
The next part is confusing...
Tried to blink test it... will not blink....
I folowed the instructions implicitly, but the lamp stays on regardless of whether or not the ignition is on... I am going to post another thread about this, to see if it can be worked out...
So I cannot pull fault codes off whatever I do...
I removed the engine fuses, left it while I had a coffee, replaced and droive up the road... I could not get it to overboost protection cut out mode, but the car is definately not pulling as well as I think it did. I don't have a boost guage, but might look at plumbing one in even if its just temporary...
I am now stuck, it was over 30 degrees today, which is why it might be working without the protection, I will take it out tonight to see if it any different when it is slightly colder....
Will keep you posted , and maybe try something else...!
Cheers
Chris

[l455lnk]

i have had a similar problem with my aby S2
on full boost the engine cuts out usually passing thro about 3-3500 rpm
this persists until you switch off the ignition
the problem may occur again within minutes, or as of the moment, not for some weeks
no leaks as far as i can see
i believe turning off and on again resets the blink codes, and this fault
i havent been in a position to pull the codes during an episode as it usually happens in awkward places so i just keep switching on and off till it goes away
does yours do the same?


cheers
paul

[LHD_Kid]

Paul, hmm, mine is different, it is not revs dependant, it is power (or more likely torque) dependant, it is just at max power level in any gear, or any revs, for example happens lower down the rev range in the higher gears...
stopping and starting makes no difference, temperature seems to make a bit of difference... I wonder if its the MFTS, been reading some interesting posts on that little thing....
I will run the car with that disconnected tomorrow to see if it makes any difference...
Chris

[LHD_Kid]

After everything, drove up the road tonight, gave it stick second to third.... overboost protection cut in, why am I not surprised...
Will have to wait till tomorrow and I will try without the MFTS in the loop...........

[newsh]

Of course its possible someone has fitted a stronger wastegate spring?

[Greg_S]

Do a search through the forum on the altitude sensor, I kinda remember something cropping up with that before

[LHD_Kid]

I am wondering if I would be as well to get a new wastegate diaphragm and standard spring, and change it just to be sure...
Any ideas on the subject?
Altitude sensor, I have cleaned the potentiometer bit of it, but dont have a meter to be able to bend things or adjust to read anything different (or even to check it...) It does seem to move easily, and be clean though......

[LHD_Kid]

OK........ borrowed a meter and adjusted the APS to show approx 1200 across the pins, put back in... no difference... still overboost protection cut in at full boost at WOT...
Would a faulty MAP sensor in the ECU cause this problem? If so, what about an ECU upgrade to magically fix the trouble (although I am fully aware that it is best to upgrade a working car, what if it is the MAP sensor.............)
Any opinions?

[LHD_Kid]

Well, there is no way I can even get slightly close to being able to unplug the MFTS so this will not be checked... I will replace this when it comes apart for everything else...
Will start a new thread, because nobody ever bothers looking through long threads to suggest solutions...
Chris

[marius_s4]

Ai schimbat cumva bujiile??

[LHD_Kid]

Da, am schimbat cu ulei si filtrele... curele si liqid de frana, acum o luna...
Acum, nu stiu problem... poate cu ECU....
Am vorbit cu Mihnea, poate merge mai bine dupa upgrade... pentru ca eu cred posibil problema cu sensor MAP...
Mai vedem...
Noroc
Chris

[marius_s4]

Eu zic ca de acolo este problema schimbale cu cele vechi sau cel mai bine cu Bosch F5DP0R . Acelas lucru am patit si eu si erau bujiile.

[LHD_Kid]

Timing was absolutely spot on, although the leads are a little bit old looking, and are beginning to crack... maybe this has an effect...(I have ordered some 7A ones as they are cheaper...)
I have changed back to the 3B standard airbox, and it works perfectly... does this mean I can't improve the intake...? maybe I can't use an ABY or RS2 version either? wonder why not.... I am going to post a thread about this specifically to see if anyone knows why this could be...!
Thanks for all the helpful suggestions, at least I know the rest of it is reasonably healthy...!
Chris

[porkkis]

Adjusting the altitude sensor is the worst idea ever on this forum. Do not touch it!