Any Vw/Audi experts on here, got a 1.9tdi with boost problems
 

If disconnecting the MAF makes no odds, its could well be that thats causing the issue, its possibly knackered, or dirty, try cleaning it (IIRC brake cleaner works). Failing that have you checked all the hoses and the EGR, that can get gummed up. Might need to do a VW forum to find out where it is and how to get into it.......

Thanks for that, i gave the MAF a spray with carb cleaner last night, but it also made no difference. Also the EGR is approx 1 year old and still looks like new.

I always thought that if you disconnected the MAF and it made no difference that it was ok, but if it made the car better then clearly it was at fault, not sure if im correct tho.

Will also be checking all the vacumn hoses later on as ive read on a few forums that is common.

I use http://www.vwaudiforum.co.uk/

That's also mys understanding (on pugs anyway) as it defaults to a 'limp mode' that ignores the missing sensor and uses a basic map which will drive OK but not be optimised.

Yes, will depend on what the strategy is for a missing/incorrect MAF signal. But it sounds like you've covered all/most of the intake issues.
I have no idea beyond that :confused:

Silly question but did you clear the codes after you read them and replaced the sensor?

Hi, the issue is still on-going. I tried another sensor which made no difference, then the turbo was removed and reconditioned (by myself) but the fault is now being traced back to the wiring loom connected to the MAP sensor, one wire has been repaired previously, so a good indication a fault maybe the cause of the trouble.

Will be spending the day on it tomorrow so will update with result.

Depending on age car there is a plastic tube that comes off manifold and go's to the ecu. You will find this is blocked with oil.

It is an inherent problem with older Audi/vw that later got changed to a sensor.

If your car is the tube version you need to replace the tubing with silicone tubing all way from the manifold to ecu.

Over time carbon gets stuck inside tube then oil thus giving false manifold pressure to ecu and causing car to go into safety mode.

That's my thoughts on problem anyway

No disrespect intended Jason but what kind of car would ever have a gas pipe to an an electonic control unit which gets oil in it? LMFAO:wtf:

Could this be an ecu fault or wiring to the ecu. Check and clean the plug. It could be intermittently putting the car into limp home mode

Erm, one with a remote sensor in the ECU? We have quite a few remote sensors around and about the auto industry. Mainly as the sensors we need to use aren't robust enough to be put next to what they need to sense. (Too hot, too much vibration, too much contamination, too much moisture, and so on.)

Not familiar with this one in particular, but have dealt with a few others.

And FWIW they are getting much much less common.

Well my Audi A4 1.9TDI 110bhp estate car has

And it was also showing the same problem as what was described

I did also state that the newer ones went over to a sensor

And it is common problem on older Audi VW and ford that run same engine

But what do I know
:p

Ring awesome GTI in Manchester they should know!

I had a similar problem with my Mk4 gttdi golf.
It would go into limp mod once every morning.

I found i could turn the car off whilst moving which sounds very danderious, turn it back on and it would be fine for the rest of my journey.

I to went to vw and had the computer plugged in.
It came up with a high pressure warning but no fault.

I eventually found it was the boost charge sensor that plugs into the top of the intercooler, at least on mine anyway.
The sensor is directly under the windscream waster bottle and i think my problem was when i filled up the bottle, the spillage was going directly onto the switch/sensor.

I changed the sensor which was abt £45 and always take care filling the washer bottle up know and since then i have had no problems.

The position of the sensor can vary on different age cars but it will the either on the intercooler or in the pipework to the turbo.
Much the same as the air mass sensor is on the air inlet.

I hope this helps.

Jamie.

Sounds like a MAF problem ideally you need to run some logging against it which will confirm it.

Im 99% sure it a wiring fault to the MAP sensor, i tried a new sensor last night and the code still kept coming up, despite the engine not running and just sitting there with ignition on.

Sometimes on the road it goes great, but other times i cant get it to boost at all but there certainly seems to be no consistency to it, im almost certain now its a wiring fault or corrosion on the plug in the loom.

Will hopefully strip and clean when i get a chance and report back.