16v HDI drives good but dosnt get any boost till about 3500 revs

after getting good advise on my cambelt question
i now have a turbo actuator question or two
as i understand my car has a variable turbo and i am getting confused as to what position the actuator rod shouls be at with engine at tick over
the car drives good but doesn't feel like it gets any boost till about 3500 revs
at tick over the actuator rod is fully extended , if i pull of the vacuum feed off and put my tongue on end of pipe going towards rear of engine there is barely no suck ,
and if i suck the pipe on actuator side it pulls up fine
thanks in advance Tim

1968unclefester wrote: if i pull of the vacume feed off and put my tounge on end of pipe going towards rear of engine there is bearly no suck ,
and if i suck the pipe on actuator side it pulls up fine

There is a vacuum pump on the right side of the engine as you stand facing the windscreen. This provides vacuum to the variable vane actuator (via the turbo boost solenoid valve), the EGR solenoid (via the EGR solenoid valve) and the brake servo.

The vacuum pump is arrowed in red and the white arrow points to the thermostat housing.



Left arrow shows the position of the turbo boost solenoid valve, down the back of the engine



This is the turbo boost solenoid valve tucked away behind the engine


The turbo boost solenoid valve controls the amount of vacuum provided to the variable van actuator - the bit you disconnected by pulling off the pipe.

The variable vane actuator arrowed and controlled by vacuum.


At idle you won't want any boost, but I would expect more vacuum delivered to the variable vane and more boost as the revs rise. Its driven from an engine map to match boost, to rpm, torque and smoke generation etc.

At any RPM, I would expect the output of the vacuum pump to be pretty constant.

thanks for info
think ive just made things worse , just adjusted the free play in actuator rod and within 5mls the eng managment light has come on
de adjusted rod , can i reset the light ?

1968unclefester wrote:thanks for info
think ive just made things worse , just adjusted the free play in actuator rod and within 5mls the eng managment light has come on
de adjusted rod , can i reset the light ?

If its an over boost error, it should clear after a few starts and no over boosting.

If it doesn't clear, you may be lucky enough being a 2004 to have an OBD2 reader (here) read and clear. A read would be useful to know what you are clearing.

thanks what one will i need as ive seen them from £9.99 and up do they have the same plug or is citroen a special size

is this the correct one
https://www.ebay.co.uk/itm/MaxiScan-MS30 ... 2910460693

1968unclefester wrote:is this the correct one

Its like this for a 2004

Arfur Dent wrote:you may be lucky enough being a 2004 to have an OBD2 reader (here) read and clear.

2002 HDi 16v doesn't , but 2005 does work with any of the OBD readers. Yours being 2004 makes it difficult to know either way. Easier to just get one and try. If it doesn't work, you will need lexia - cross that bridge only when you come to it because it can get quite tricky.

1968unclefester wrote:thanks what one will i need as ive seen them from £9.99 and up do they have the same plug or is citroen a special size

Its the same plug size for 'lexia only' and the generic OBD readers - just the pins layout are different.

ok chears

well looks like its the electronic boost valve thingy plus i snaped the poxy Variable vane actuator
anybody have the part numbers / e,bay numbers so i can order the bits