03 V40 1.9D 115bhp power loss

[V40DSchariot]

Well, I took car to another garage this morning. An authorised Volvo garage, but not a dealer. Originally I was booked in for an hour for diagnostics. When I got back, they had spent an hour on it, no faults, but they had found a problem with the turbo vacuum circuit. They could'nt spend anymore time on it but mechanic pointed out the area's to look, at a reasonable price aswell.
He had a gadget to pressurise and create a vacuum and got her running, reving all way round.
When I got home I started looking through pipes again and had a test pipe to systematicaly swap until I found the problem area. It turned out to be the valve underneath the cylindrical valve bolted to manifold. I'll try a photo.
Hmm, uploaded photo but don't know if it's attached to this thread. Anyway, car's pulling like a train, switched off several times and upto yet been good.
I took the pipe off that goes to the little valve and sealed the end until I get a new valve.
Huge thanks to Baffler for all the pointers.

[Derek UK]

Is everything now all good? If so, what is the exact name of this valve and what does it do or control?

[Baffler]

Originally Posted by Derek UK

what is the exact name of this valve and what does it do or control?

That solenoid actuates the air inlet shut off valve once the ignition is switched off and reopens the valve a few moments after the engine has stopped in preparation for a restart.

[molemot]

I've had a very good look at an enlargement of the photograph in V40DSchariot's last post. I don't think it's a valve of any sort; certainly nothing to do with the air inlet shut off butterfly valve. It seems far more likely to be a differential pressure sensor...having two input pipes ( one of which has been detached by V40DS) which seem to feed to either side of an internal diaphragm....thus sensing the difference in pressure between the two input pipes. The electrical connection can clearly be seen behind the sensor, with the corrugated trunking apparent. I would love to know where the two pipes from it went to...especially the one that's been taken off!!

I'm rather hoping this sensor will have something to do with my weird surging problem...which is still apparent, and occurs only from 2800 to about 3300 rpm.

[molemot]

I'm a twozzer!! Yes , the thingy is a solenoid operated valve....switches the vacuum through to the idle cut-off butterfly valve. I've been tracing the pipeworks and now have a much better idea of what they all do....see my thread on the weird surging of the V40!!

[V40DSE]

Can anyone tell me what the valve is called underneath the cannister on the back of the inlet manifold, as I am trying to find a replacement one for mine and don't know what to look for on eBay.
Regards
Glen