Very poor performance on Fabia vRS

[saksager]

Hi

I am experiencing very low power output from my engine and hope that you guys here can help me sort things out and find the problem.

The symptoms are the following:

- When starting the engine, I can hear the turbo spooling up, but there is no torque until I reach around 3000 rpm. Then the turbo kicks in with around 1.2-1.3 bars - read out via vagcom. My car is remapped and should be running 1.6-1.7 bars. The power after 3000rpm is "decent" and comparable to a non-remapped vRS.

- When accelerating to 130 km/h (Danish motorway speed) I reach 120 km/h in 4th gear, and the turbo pressure is gone because the engine runs in fault mode (if it is called so in english) - the yellow warning light turns on.

- Stopping the engine and starting it again will repeat the two steps above every time with no exception.

- When stopping the engine BEFORE it enters fault mode, the engine shakes/vibrates more than usual.

- When stopping the engine AFTER it has entered fault mode, the engine comes to a smooth stop as it has done until a few days ago.

I called my mechanic to have him read out the fault codes with vagcom, and there were two errors. I don't remember them exactly, but something like:

- EGR valve error

- Boost Pressure Valve Error - manifold pressure too low.

I tried to change the air mass meter (since it is easy) but it didn't help at all.

Can anyone point me in the right direction about where to look? The obvious would be to change the boost pressure valve, but are there any other opinions about what might be wrong?

I am a bit worried there might be something wring with my turbo, but should I be afraid of that?

Thanks a lot

[djswivel]

Is it producing extra soot? If so, then it's possibly the turbo.

Could be the EGR.

Could be that your map has to harsh a spike in it forcing limp home mode to come on.

[Conshine]

Could be the N75 valve, I remember a thread on here about this when you have boost problems as I recall that it works on pressure which in turn moves the vanes in the turbo.

Mine is good on boost up to about 2500rpm then it really seems to hold back, i.e. no boost as it really creeps up on the revs.

Looking into it now :confused:

[saksager]

Hi

I have been using the map for 50000km, so it would be odd if it would begin to make strange things now - wouldn't it?

Black smoke - not too exessively in my opinion and mostly right before the turbo kicks in. Excatly as when you floor it from idle - it produces black smoke until the turbo kicks in.

How can I test the EGR?

[devonutopia]

"Boost Pressure Valve Error - manifold pressure too low"

This to me points toward the boost pressure sensor, but I could be wrong

[jasc1988]

Could be the N75 valve, I remember a thread on here about this when you have boost problems as I recall that it works on pressure which in turn moves the vanes in the turbo.

Mine is good on boost up to about 2500rpm then it really seems to hold back, i.e. no boost as it really creeps up on the revs.

Looking into it now :confused:

Mines has started doing this :thumbdwn:

Only seems to happen when your giving it the beans right through the gears, 2nd,3rd,4th etc. But then as soon as you change to 5th it brightens up again

4th is the worst :(

[Conshine]

Mines has started doing this :thumbdwn:

Only seems to happen when your giving it the beans right through the gears, 2nd,3rd,4th etc. But then as soon as you change to 5th it brightens up again

4th is the worst :(

yes, 3rd and 4th are sh**e, may look at the MAF first as there is a mod for it using dielectric grease in the terminals - do a search on how to do it, it may help.

try taking off the connector and drive it and see if it's any better?

[jasc1988]

yes, 3rd and 4th are sh**e, may look at the MAF first as there is a mod for it using dielectric grease in the terminals - do a search on how to do it, it may help.

try taking off the connector and drive it and see if it's any better?

Ive done the MAF mod, its only recently ive noticed this, 3rd is okay sometimes but othertimes its not soo good, then 4th is just a no go but when i change to 5th it really really brightens up... Just cleaned my green cotton panel filter tonight so we will see if that helps, havent cleaned it for 10k lol

[markyvrs]

losing top end power sounds like MAF failure to me.

then again it will probably turn out to be something completely different

[jasc1988]

losing top end power sounds like MAF failure to me.

then again it will probably turn out to be something completely different

Ahh right bud, how do you fix it??

[saksager]

Sorry for my lack in english - what is MAF?

[Conshine]

Ahh right bud, how do you fix it??

You just have to change the MAF, not too difficult and costs about £50 - £60 IIRC.

Therer are threads on here showing how to do it with pictures.

[Conshine]

Sorry for my lack in english - what is MAF?

Mass Air Flow (I think)

It basically sits in the intake pipe from the air filter and measures the mass of the air flowing through and I think the air temperature so the engine management can work out the fueling correctly....or something alon those lines??

[ric04vrs]

Sorry for my lack in english - what is MAF?

the same as an "air mass meter"

[saksager]

Ok I get it. Have tried that already and it has no effect :(

[RSI]

Hi,

you have checked all the hose connections from turbon to EGR? the hose closest EGR valve is usually pop out ..

check for crack in EGR tube, From the exhaust.

also check the EGR valve for dirt.

It's my tips

Good luck

[saksager]

I'll check the tubing for sure - everything that is not as costly as a new turbo is where I try first

[Tech1e]

A couple of possible causes.

The turbo cannot make the boost pressure (knackered turbo (running 1.7 bar I wouldn't be suprised) or a leak somewhere.

The turbo is making the boost by the ECU is reading it wrong (faulty pressure sensor)

The EGR is stuck open, this then would be diverting exhaust gas away from the turbo back into the inlet. (quite likely given the other code).

[saksager]

I am hoping for the cheapest ways to solve this, so hoping it is a sensor or valve.

If it is the turbo, what should I then look for? There is no oil leak or similar, so there are no cracks in the housing I suppose.

[clidgevrs]

mine too seems a little rough etc and does not seem to be pulling as much however I have a leeking egr valve so getting this sorted on saturday so fingers crossed this will improve will put back a response after saturday.

[saksager]

mine too seems a little rough etc and does not seem to be pulling as much however I have a leeking egr valve so getting this sorted on saturday so fingers crossed this will improve will put back a response after saturday.

A little rough? Do you mean shaking/vibrating more than usual whan stopping the engine?

[viewer]

Quickest and cheapest investigation would be to pull pipe off EGR and have a look inside. Bet it looks black and oily. If in doubt take it off and give it a clean (lots of guides here and in TDI club website). It is easy, but wear thin gloves or you'll have black finger-nails for weeks!

Best of luck

[saksager]

Quickest and cheapest investigation would be to pull pipe off EGR and have a look inside. Bet it looks black and oily. If in doubt take it off and give it a clean (lots of guides here and in TDI club website). It is easy, but wear thin gloves or you'll have black finger-nails for weeks!

Best of luck

Just any pipe or which one preferably?

[RSI]

I think he means the EGR valve:)

[Conshine]

I think he means the EGR valve:)

Oh that's what it looks like, may take the pipe off and have a look.

Do I need anything special to clean it with?