solenoid vacuum switchover valves

[andy8966]

Does anyone know what solenoid switchover vacuum valves do?
My 2.0 DTI does strange things and I've tracked it down to the near side solenoid vacuum valve which controls the throttle valve vacuum plate on the inlet manifold. The revs go AWOL at times and I've noticed that the throttle valve is being opened and closed such that the revs die due to air starvation. If I pull off the little pipe which is connected to the solenoid it runs nicely. I left it off a couple of days ago but it drove like a stale F*rt!
Stripped the solenoid (watch you don't loose the little springs inside!) cleaned it and lubricated it with WD40 last night - this morning a dream but coming home from work it was all over the place again!
If I have to replace it any ideas how much from the steelers?
Or does anyone have any ideas how to sort the little Bas**rd out?

[rickyroo]

Is it a DC coil solenoid valve if so does it switch correctly if your connect the +ve and -ve from battery?

These are controlled via the ecu Logic via external inputs and basically are switched as the above with +12v supply once the mapping logic is at a certain tolerance level, these only go for really 2/3 reasons. Poor manufactuer of component 50/50 chance, their is a fault with the vehicles turbo / air source, electrical fault.

Test it and change it mate.

[Green Growler]

First thing I would do is check, double check, and then just to be sure triple check all the vacuum pipes for any sign of perishing.
It only takes a tiny little crack (which can be nigh on impossible to spot) to wreak havoc.
The DTI engines in the Vec B are well known for splitting / cracking vacuum pipes, and depending which one goes depends on what sort of chaos it creates, just be thankful it still starts.
I have been under my bonnet today as it happens, and I noticed the rubber ends to several of my vacuum pipes are already cracking / perishing.
So I won’t be waiting around for a failure, I’ll be replacing and upgrading the whole lot ASAP.