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Hi guys and girls.. probs with my TDI sport 100.
I've lived with it for about a month now but I really need to find the cause of this problem.

The Problem

Anywhere between 50-80ish mph in 4th or 5th gear I lose all boost pressure, I can feel it straight away... it's as if I haven't got a turbo anymore!
If I stop the car, turn the engine off and back on again it resets itself and all is fine until it decides to do it again between 5 and 30 miles later.

What I've done

I've had Vag-Com on it twice and it hasn't thrown up any faults relating to the turbo.
I had my suspicions it was the MAF sensor, so after the fault came back I disconnected the MAF and carried on driving. It didn't fix it, so can I rule out the MAF?
People have suggested the dump valve could be sticking, but this sounds mechanical and the fault seems electric-ish.

The car has been re-mapped but drove fine for well over a month before the fault occured.

It seems like it thinks it's over-boosting and the ecu is going into safe mode, why now and not before I don't know!!!

Sorry for the long winded explanation, any help would be much appreciated!!

Cheers, Paul

My friend has the 110 ibiza diesel and he had the exact same problem with his car and it turned out it was the Maf sensor he had exactly the same symptoms as you and this is what it turned out to be.

Good luck in finding the problem but it does sound maf related

Claire

Cheers for that, I'd be more than happy if it is the MAF sensor as its a pretty easy fix.

Well my mate has went thro 2 in the past year

would be a lot easier if u knew someone with the same car as you to swap over the maf and see if it cures the prob

Claire

Sounds like its the MAF. Common problem when it comes to losing boost pressure.

Its not impossible that your ECU re-map has become corrupt too.

I'll go the MAF sensor route first, then if it doesn't solve it i'll chat to the tuning company.

Cheers guys!!

where are you based?

I work at RAF Brize Norton in oxfordshire and live in Gloucester.

Right, I have finally bitten the bullet and bought a new MAF sensor from our friend Mr VW.
£90 - £20 (for my old one when i take it back).

It's changed over, off to take it out for a test drive in a bit.

Fingers crossed

let me know how it works out

Right, I've driven the car for around 50 miles since changing the MAF............
And the problem's still there!!

Not a happy bunny, oh well just have to keep on looking!!
At least I've got a nice new MAF.... great!

chin up, you could probably get a few quid for the old one!

Sorry it didnt work!! You have to be careful with this as my pal changed the maf then it was put on to the vag com system and they couldnt find no faults he then put it into seat and they said it was a faulty maf sensor problem. I''ve read on forums that the Exhasut gas return valve can get clogged and perhaps cause the above symptons to happen im no expert but im sure one of the boys will be able to help you

Claire

ps check the mod for a GT/TDI its about maf connections its the topic below this one (or at least was at the time)

Sorry to drag my own thread up from the depths of the forum, But I'm out in Qatar for a month wiv the RAF and am a bit bored.... sand and more sand!!

Looking 4ward to sorting my car out!

Just letting u all know what I'm gonna b up2 when I get bk..... the problem was still there after an MAF change and and EGR valve clean.

I was gonna get a new/recon turbo but spotted something before I came out.... a company called innotec do a turbo clean package that clears all carbon out of ur turbo/variable nozzle (as fitted to the 1.9tdi) so hopefully it will free it up..... it's only £35 too!! If anyone has the same prob look at www.innotecworld.com

Hope ur all getting pissed up as I can't!!! lol