Cut Off(Overboost protec.), when driving uphill bad gas pump?

[Jonas_R]

Well,

I have changed all pressure hoses, MAF, ISV, Lambda, N75, Re Cirke valve with one from S3, Marh H IC mod

But i when driving full throttle uphill, i suddenly get a cut off. And then it wont go away before i turn of the car. Then i have no problem going full throttle?

Any suggesten? Perhaps a bad fuel pump?

Can a respected turner turn down the sensitivity off the overboost protection?

/Jonas R.

[S2central.net]

Overboost protection is a good thing Jonas - I wouldn't want to mess with it - plus I don't know how actually. But your car must have a problem to get the fuel shutoff. Normally its an air leak or faulty MAF.

Checked the WG diaphragm yet ?
What about PCV system ?
or the miles of narrow guage vacuum tubing ?

[Jonas_R]

Overboost protection is a good thing Jonas - I wouldn't want to mess with it - plus I don't know how actually. But your car must have a problem to get the fuel shutoff. Normally its an air leak or faulty MAF.

Checked the WG diaphragm yet ?
What about PCV system ?
or the miles of narrow guage vacuum tubing ?

Well all hoses are changed and MAF is new like 2 days.

What is the WG diaphragm and can i buy it from audi?

PCV system what is that?

Did a pressure test on the guage and it was fine, held 2 bar pressure without a problem.
So far the problem has only happend when driving uphill with full throttle, and then the problem dont go away before i turn off the car. When i turn it on again, there is no problem and i can floor through 2nd, 3rd and 4th. I think this i kinda strange?

/Jonas R.

[Jonas_R]

One extra question Paul,

It seems that sometimes i can get full boost from like 3500-5000 1.3 bar, then when it hits 5000 rpm it cuts off. Can this be becaused by the WG og PVC system?

Other times it simple just want go over 1 bar in pressure.

/Jonas R.

[Henka]

Check the pump. Before my pump died completly the car ran like crap sometimes and somtimes it ran just fine. Then, one day.....It just wouldn't start. Got a blink code indication lean fuel condition (IIRC) --> pump dead.

[Jonas_R]

Check the pump. Before my pump died completly the car ran like crap sometimes and somtimes it ran just fine. Then, one day.....It just wouldn't start. Got a blink code indication lean fuel condition (IIRC) --> pump dead.

Yeah but did your car make cut off? or did it just run bad? Mine does cutoff like overboost protection. But i cant seem to figure out where the hell the problem is

This really sucks big time....

/Jonas R.

[S2central.net]

Well other candidates are the altitude sensor and MAP sensor within the ECU, but you should rule out any and all sources of air leak.

Its not always easy to see why a leak can cause overboost protection, but here's an attempt at expplaining it. If the car has a leak in the intake plumbing then it causes a loss of boost pressure, but when the car is in vacuum then the leak causes UNMETERED additional air to enter the system - if the ECU determines that absolute manifold pressure is much higher than it should be for the prevailing conditions then it triggers overboost protection.

A common cause is the MAF - did you replace this with a brand new one - or a known good 2nd hand one ?


Paul

[porkkis]

There is a limit for the air mass AFAIK. This can be the issue here. Boost leak, I guess. Too much air enters the MAF and at 5krpm you found the limit.

How did the problem occur first time? After some work or before all you mentioned?

[Jonas_R]

There is a limit for the air mass AFAIK. This can be the issue here. Boost leak, I guess. Too much air enters the MAF and at 5krpm you found the limit.

How did the problem occur first time? After some work or before all you mentioned?

Well the problem occured a long time ago, but then it sometimes helpted to clean the MAF. Then after a while that did not help at all, it just got worse.

Then i changed everything, and the problem went away for like a week. Then one day going uphill, full throttle in 4th it came back and i got the cutoff.

Then i went home turned off the engine. Later the same night in went for a spin and did full throttle from 140 - 250 km/h in 5th and there was no problems.

The weird part is that, when this cutoff happens perhaps at 5000 rpm, then i cant get over 1 bar boost in any gears afterwards. I need to turn off the engine before i can get over 1 bar of boost.

I do have a HKS filter fitted almost directly onto the MAF, if this is bad i can change back to the normal air filter box?

To Paul,

I bought a brand new MAF from audi, everything else i mentioned is also brand new. I just wanted the problem to go away.
However, i would like to now how to test the PCV system and what it is?
And how to test the WG diaphragm and what it is?

[porkkis]

Try with the factory filter. You should have something to avoid turbulences in MAF. Something like the cross in the original filter box. Look at it and you know what I mean.

Now I'm too tired to think about the right words

[ericd]

Well,

I have changed all pressure hoses, MAF, ISV, Lambda, N75, Re Cirke valve with one from S3, Marh H IC mod

But i when driving full throttle uphill, i suddenly get a cut off. And then it wont go away before i turn of the car. Then i have no problem going full throttle?

Any suggesten? Perhaps a bad fuel pump?

Can a respected turner turn down the sensitivity off the overboost protection?

/Jonas R.

If this problem is easily repeatable, clear the errors in the ecu (or pull the fuse for a few mins), run the car to you get the problem and post the errors recorded if you can .
I know it's probably been mentioned before but maybe not in this thread , I read that you've got a new MAF, but I'm assumming it's still the original electrical connection block, I'b tempted to give this a clean/brush with elec. contact cleaner and reseat it a few times before securing it , probably not your problem , but there's been a few recently which had this issue.

HTH

[The Spanish]

The same thing happened to me. Engine would cut off some day and then the only way to drive it was to re-start. I got use to press the clutch on the motorway, turn out ignition, turn it on and release clutch to restart the engine. I now know I had three problems. Air leak (small), fuel pump going out and one of the coils almost dead. I also cleaned the MAF. After all this car goes perfect but I am not sure wich did what

But I am sure you should feel like the engine is not climbing revs as smooth as it should even if it does not cut off. Specially in 4th or 5th gear going uphill. Around 3-4K rpm

WG diafraghm is the diafraghm (part that seals) the chambers inside the wastegate, maybe you are loosing air through the top of the wastegate, this has happened lately to some cars. You can test it by applying air pressure in the lower chamber of the wastegate. It should be a while before air leaks through the top.

PCV system I have no idea.

Check the fuel pump, fuel filter, lambda probe and the coils if you are sure everything else is ok. What about the Intercooler O-ring?

Cheers

[S2central.net]

Eric beat me to it on this, but you MUST reset the ECU to make it forget about the fault. It might be a rare glitch that triggers the fault, but it stays in ECU memory until you clear the fault codes with VAG-COM or just unplug the ECU for a minute...

A MityVac is the weapon of choice to test the WG diaphragm - that needs to be airtight. If its not the engine can draw in unmetered air...


Paul

[AAH!]

PCV system what is that?

PCV = Positive Crank Ventilation - The oil breather system.

There is a replaceable breather valve and a flame trap that can get clogged with oily gunge as can all the breather pipes.

http://www.sjmautotechnik.com/trouble_shooting/20vboost.html#hose

[Jonas_R]

Paul,

To reset the ECU, can i then just pull out the 2 fuses taht say motor in the fusebox?
With the MAF the only thing not new is the cord that you connect to the MAF, this has been sprayed with contact cleaner and so has almost every other connection in the car.
What is the price or part number on the wastegate diaphragm? If it aint expensive i'll buy a new one

So the PVC system can also be a problem, what in the PVC system should be changed? The main hose?

oki willtry the airfilter box first if this fails, new PVC and WG diaphragm.

However, if any body can tell me details how to mount a catch tank?, i would be happy

/Jonas R.