No power on kick down after extensive turbo work

[Mike_T]

Hello guys - my garage is at its wits end and I'm feeling guilty to keep going back.
I have a 2005 Automatic S Type Diesel
This problem started with consistent restricted performance and so the turbo actuator was changed. [Are there 2 Actuators? I believe one was previously changed not that long back]. When the car returned within a couple of miles it again showed a restricted performance and limped home but started to make an awful noise like a tractor, loads of black smoke and eventually cut out and stopped.
The breakdown/repair guy came, (about 2-1/2hrs later) - he asked me to drive it into position to his pick up truck - and I was really fearful to do this but he cleared the fault and the car started and actually drove fine. he said it was a false electric signal and to drive it back into the garage to be checked. The car drove fine for a couple of miles and the same fault came and I limped the rest of the way to the garage.
The garage said that the other EGR valve had now gone. We previously replaced the alternate EGR valve. Work done, car returned. Drove perfectly for a couple of miles but then exactly the same problem. Really low power, tried to limp back to the garage but the car came to a complete stop.
Now it transpired that there was a problem with the vacuum - and that the rocker box cover had been damaged and the seal blown. This was also fixed, again the car went a few miles and the same problem came back.
When the tractor noise was there and progressive less and less power - bucket loads of black smoke always flooded out the rear of the car. The black smoke was a problem from the start.
Again the car went back. From this point the garage have not charged me for any work or time. They realised that the vanes which they were testing manually were moving fine when the car was cold but as soon as the car heated up the vanes became stuck - hence the reason it drove a few miles and then failed. When the problem looked to be solved - it was still there.
Then they found out the actuator originally replaced at the start of this work was faulty. That was replaced again.
The Turbo was found to be really dirty and carboned up. The guy took the turbo apart, totally cleaned it put everything back.
The car drives again like a dream. The engine pulls and is strong. There's only one problem though - when you kick down and need some power - to try and dart out into traffic or onto a roundabout, or on a motorway to fire past someone, the revs go right up and the car mimics a restricted performance mode. it doesn't accelerate the speed stays consistent - either at 20 mph, 30 mph or at 70mph.

Is there anything obvious which is being missed - anything anyone can suggest?
Thanking you in anticipation.

[jeff1954]

It could be the MAP manifold absolute pressure sensor that fits into the top of the throttle body. they get clogged up over time, they can be cleaned out but in my case I needed a new one which has been modified. I would recommend buying a genuine Jaguar one.

Jeff

[andypryce]

Hi Mike,

I am assuming fault codes have been logged and investigated? Sounds like it needs some specialist engine management investigation to me, not sure where you are located, somebody may be able to point you to a good independent with the right knowledge? Agree MAF sensor worth cleaning, though if engine runs sweetly generally then unlikely to be this I think.

[andypryce]

Ignore last bit, misread previous post.....

[Mike_T]

Andy/Jeff - thanks for your comments I am going to pass these on. I apologise for the delay in acknowledging what you've said. I was waiting on a notification that my post had been approved. I was expecting an e-mail and didn't realise I needed to come looking.
Again - thank you for your input.