Help me!!!! Ignition Fail! Low fuel pressure??? Failure 2341

[BlackBullet]

Hi people!

I have an S2 Avant ABY, and one day my fuel pump stoped to work... than... I have changed for another S2 fuel pump (it wasn´t new.. but works well)... than have passed same days, than it cames with a little failure on the ignition... Normaly, when you need power... for exemple on an ascent! This failure was very quickly!

What I have made!
My car was with 70.000kilometers, with the original spark and sparkplugs... I bought new sparks and new sparkplugs!
The fail occurs...

This time... when I have tested... I went to the road.. and test the boost! When occurs the fail... We need to go slowly with the throtle!!! When you make WOT, at the pedal, than as a snapshot cames the fail and the ignition cut! My neck really do not like that move!

So.. I passed the Blink Code.. and it cames the fail 2341!
2341 fail says:

- Lambda Sensor control Maximum or minimum limit exceeded!

Can be because:
- Low fuel pressure (<3.3bar) or High fuel pressure (>4bar)
- Ignition system faulty
- Intake air leak
- Leak on exhaust
- G39 Faulty!

So...

My Idle is strange to...
It would stay at 800RPM, but it oscilate quickly to 700RPM, tha go up to 900RPM... a little strange!
It´s like a cylinder fault!

Than I thought that can be the POS or the Coil Packs!
So.. to test...
I have unpluged witch injector until the failure cames stable. I found that on cylinder 1!
So... I have changed the POS... than if it was the Coil Pack at the first cylinder, the failure will stay at the cylinder 1.... If it was the POS.. the failure need to go to the cylinder number 4!
Surprise.... It goes to Cylinder number 5!!!
But it was quickly and hard to identify if the failure was at the cylinder 4 or 5!


So.. On doubt, I have changed the POS!!! And... SURPRISE for ME.... The failure is there!!!

The Coil Pack can´t be!!!

Leak??? I really do not agree... because my problem is on idle!

Can be Low pressure??? What is the syntom???

This week, I want to buy a Fuel pressure instrument to measure this pressure... but.. any one can help me with another idea???

Thanks a lot!!!!

[BlackBullet]

nobody?

[Mihnea]

Boost leak.

[BlackBullet]

I'm not sure... because it heppends on Idle too... (without boost)!

But a friend of mine, saw that the fuel pressure may be OK! Because if the problem occurs on Idle, and I can go out with the car out... than I have pressure on the fuel pipes!

I agree with him!!

It's right?

[urquattro-island]

check

your hoses for leaks and your pressure relief valve, how about your fuel filter? dirty??

[BlackBullet]

So.. my fuel filter is absolutely clean (NEW)!

Now I really do not know what happends!!!

I have reseted the ECU, and go out to test!
With cold motor... my idle is @ 1000 RPM... some times goes up to 1200RPM but quickly, and than cames to @1000RPM!!!

Than I went out and check the boost! I´ve got it!

when I was on 3th gear, with my foot down on floor, near the 6500 rev cames the fail... The ignition simply cut!!!
Than, when i make WOT, the car starts to kangorooing!

I made the blinkcode, and this time I got 2224!
I think that is the overboost protection...

On my boost gauge, I have 1.3bar of boost! But I need to make new tests on it!

What you think about?
What part can make this problem??? N75???

Cheers,

[AAH!]

Before you do anything else you really should pressure check the whole system, this includes all your turbo, air intake and vacum hoses to see if it holds pressure. It is not only air escaping you need to be concerned about but also unmetered air being sucked into the system, both will make your car run badly.

Do a search on "boost leak" (also try using "leek" ) and "how to", there is a huge amount of info on this subject as most of our cars have suffered from it at some point.

Angus

[urquattro-island]

same as me

had this problem and changed the pressure relief valve, got good then. may be the same??

[BlackBullet]

what is this pressure relief valve??? I have searched about but nothing founded!
where it is located???

Some pics would help me fine!

[AAH!]

what is this pressure relief valve???

I think he means the wastegate, (the diaphram can split). You can pressure test this.
Or perhaps urquattro-island means the wastegate frequency valve (WGFV - N75).

[BlackBullet]

I think that too.

But someone can tell me what happeds when we have a failure on the WG? or on WGFV???

Someone told me that when the WG is bad, we have less boost... either when the WGFV is bad!
This person is right?

So, if this person is right, than my fail need to be in other part. Because I gess my problem is "overboost protection", than something when fail needs to increese the boost!!!

May this occurs with the WGFV??? ou WG???


P.S. I have done the Output test on ECU! My WGFV clicks!!!