Overboosting.... Help im running out of ideas

[Greg_S]

As some of you know my car has been causing a few probs the last couple of weeks. most of which are now solved. BUT im still getting overboost problems at the moment.

I changed the WGFV last night but that didnt solve the problem. On mechanical boost with the WG disconnected I get 0.8-1Bar most of the time since it has a stiffer spring fitted.

When i fitted the samco's i found a small boost leak which has been fixed.

anyone got ideas on what else it could be?

Its drivin me nuts not having the power there anymore.

Greg

[S2 Ant]

Its not just a case that it was mapped with the leak hence mapped to boost that high and now the leak is plugged its boosting to its full potential on that map?

Or am i being a dumb ***?

[S2central.net]

Ant - Huhhhhhhhhh ?

Greg - what about PCV plumbing or the WG diaphragm. My experience of cutouts caused by overboost protection are that they have to be fairly sizeable leaks to cause sufficient unmetered air to trip the system up...

[WabTheKing]

put a 3bar map sensor in and just run higher boost like me

[S2central.net]

Yeah right - that will solve an air leak won't it !

D'oh

[S2central.net]

Oh and Greg already has a 3bar MAP...

[WabTheKing]

thought over boost was a cut out device in the ecu which standard would cut out if boost pressure went above the factory standard pressure? hence he has got a uprated waste gate spring so the boost will be higher than standard, AND thought he had fixed the leak

[WabTheKing]

Oh and Greg already has a 3bar MAP...

oh ok i will shut ma cake hole

[S2central.net]

Gregs is programmed to go over stock levels but it is an air leak (or faulty MAF) which is tripping the overboost protection mode within the ECU.


Paul

[WabTheKing]

has he got a boost guage on it to see what it is boosting? i went to a garage once where they had a thingy which pressurised the pipes then you could listen for leaks

[APNess]

The usual stuff to suggest I'm afraid Greg - you know the score. Follow the air from box to throttle body by taking every damn thing off

My bet is turbo-intercooler, but you should hear that - it's not something you can mistake. The last leak I had was only a small gap (less that 1cm) in the pipe. It would boost to the wastegate level (stock) then get to around .8/0.9 bar wooshing and flickering on the gauge like mad - engine was boosting, but most was going to atmosphere.

Since I've put the SFS 45 degree hoses on, and the T pice in the middle, no more leaks - I'm expecting any weak links to show up at this weekend's mapping session though... *crossing fingers that nothing 'weak'*

Good luck mate

PJ

[Greg_S]

Well, im fairly sure ive solved a leak because boost goes straight round to 2 Bar which i can see on the gauge, the sensor for the boost is on the IM too so its the actual boost going into the engine after other leaks etc. I havent got a mitivac tool at the moment to check the WG diaphargm. Has anyone nearby got one i could use? How would I go about checking the PCV system?

All the pipes are new from where i have fitted the samco's, ive been around and checked all the jubilee's and they all seem to be in order too.

Im not sure the ECU is cutting the boost at all, its my right foot thats done that as soon as it does it. I dont fancy having a Steve H bananna rod.

Greg

[APNess]

Well, im fairly sure ive solved a leak because boost goes straight round to 2 Bar which i can see on the gauge, the sensor for the boost is on the IM too so its the actual boost going into the engine after other leaks etc. I havent got a mitivac tool at the moment to check the WG diaphargm. Has anyone nearby got one i could use? How would I go about checking the PCV system?

All the pipes are new from where i have fitted the samco's, ive been around and checked all the jubilee's and they all seem to be in order too.

Im not sure the ECU is cutting the boost at all, its my right foot thats done that as soon as it does it. I dont fancy having a Steve H bananna rod.

Greg

2 bar?

No wonder you're finding more boost leaks.

It's a wonder you didn't spank the boy Cockings' **** at GTI Int running that sort of boost, but I guess you're a little kinder to your car than Tom is

Mmmm 2 bar. Could sort out the odd maserati with that...

[Pete_RS2]

It's a wonder you didn't spank the boy Cockings' **** at GTI Int running that sort of boost, but I guess you're a little kinder to your car than Tom is

I see young Tom got a mention in Audi Driver mag for winning the Audi 4WD class

[newsh]

Pull the small pipe from the MAF to turbo hose and plug the hole, its about 10 or 12mm, this will disconnect the crankcase venting from the inlet, run it up the road like this. It will smell in the car though cos the inlet vacuum is not drawing the fumes in, there will also be some oil mist coming from the small pipe. You could slip a length of garden hose on it and hang it out the bottom of the car just for the test.