No Boost! No fault codes! Running out of ideas, please help..

[S3 finatic]

Thanks first of all for making the effort of reading my thread!

I've not had any luck with my A4 B7 2.0 TDI 140bhp since I've had it, and i have spent hours on here looking through various posts getting ideas but not finding the answers i am looking for.

I have hardly any boost if any at all, i am driving the car on pure engine power. I've had the car scanned from 2 different resources and both came back with no errors.
I have no access to VCDS unless i visit my local garage.

I have removed the EGR and cleaned it.
Replaced the MAF with a Bosch part.
All boost pipes have been removed and checked for leaks.
The inter-cooler has been replaced with an OEM part due to a leak.
Removed and checked the turbo and is in perfect working order.
The actuator moves in and out when the car is rev'd. If i rev it slowly and hold at 2000rpm no movement, if i slowly rev it to 3000rpm no movement. It only extends when it is rev'd
The DPF has been removed and mapped out prior to me purchasing the car.

Other than the ECU what controls the boost?
A number of threads state there are 2 units to look for that controls the boost, but i can only find one on my car which is pictured below, what else should i be looking for?

Is there any way of testing these parts?

 

[tony mc]

hello mate, someone else said this to another member the other day and i thought it made a lot of sense, could you get audi or someone to reflash the ecu and take the map off and back to standard and see if you still get the problems, it could be that its a bad map causing the problem if your not getting any codes and you've already checked almost everything you can, i know that's what i would do, start over from the beginning back to square one

 

[S3 finatic]

I thought of that!
Audi was a bit long winded about it, and basically said no because the DPF has been removed.
I took it to get it re-mapped by a company i am at present not going to name, and despite taking a deposit and yet to return they could not remap it because it had been locked by the person that did the original map.

 

[tony mc]

you could try asking some of the known tuner's on here like rick at unicorn or unit 9 remaps, see if they can get past the locked ecu or is one of them 2 the name you dont want to mention lol

 

[S3 finatic]

you could try asking some of the known tuner's on here like rick at unicorn or unit 9 remaps, see if they can get past the locked ecu or is one of them 2 the name you dont want to mention lol

No its not them!
My issue is more about being promised a refund if they couldn't do it, and i'm still waiting for it.
I have no idea who originally mapped the car as it was not declared by the garage i bought it from.
I have had several people look at my car and all say the ECU needs flashing and starting again to remove the lock, but i cant afford to get that done until i get the refund from the last time!!

I should have said the problem did not start until i had a new engine fitted after the last one died after only 3 days of owning it.

 

[carlcall]

Could you not try getting in touch with the previous owner to see who mapped it?

I know this may sound really stupid but when you say "Removed and checked the turbo and is in perfect working order." are you sure as I thought mine was ok as it would still turn freely'ish but compared to my new cartridge I fitted it may as well have been welded tight.

My car didn't throw any error codes up either and it chucked so much soot out the back it was ridiculous.....but if I held it to around the 3k rpm it would all of a sudden come back to life and fly again.

I checked my turbo for spooling up from cold by videoing it and you may have the same fault.

 

[S3 finatic]

I did the same check on my turbo, and also took it to a specialist who gave it a thumbs up.

I bought it from a garage, the owners wife was using it for about 12 months until he put it on his fore court.
He accused me of remapping it which caused the first engine to go after just 3 days. Its a long long story but in short trading standards had to step in to get him to replace the engine so he's not exactly helpful.

 

[carlcall]

You can test the N75 valve you have above with VCDS.

I would look for a user near to where you live and hopefully they charge the same as me.....a few beer tokens and plenty of banter!

 

[tony mc]

So has the car been like this from the minute the new engine went in mate or was it running ok at first

 

[tony mc]

any joy with this yet buddy

 

[S3 finatic]

With the original engine it ran fine but i did feel it was not as rapid/responsive as my previous car an A3 2.0TDI.
The replacement engine had done 30,000 less miles, but sounds louder (rattly), and heavily carboned.

Not sorted as yet! However i did notice a small increase in power after i removed the inlet & outlet manifold and gave them a good clean. The exhaust manifold was OK, but the inlet had 3mm of carbon that was a right bitch to remove and clean.
I received a message from someone saying the company i have paid to map my car will contact me on Tuesday, so i will not be getting it mapped elsewhere until then.

My next plan of action is replace the boost controller on Friday just for piece of mind.
Getting the car carbon cleaned on Friday, if the inlet manifold was that bad, then i have no doubt there is more to be cleaned.
Going to double check the timing next weekend.

Then finally if that does not resolve the problem i will be booking it in to get it remapped.

 

[S3 finatic]

Carlcall I've been having trouble finding a local member with VCDS, so having to rely on a local garage.