2.0 diesel idle control

[s40_kid]

is there a specific idle control unit on the 2.0d? I can see ones for petrol model but not sure about the diesel. My idle drops to low and causes severe vibrations.

Have trawled the internet but cant seem to find anything on this and as the throttle is drive by wire i cant adjust the throttle cable like the good old days

[s40_kid]

after trawling the internet i have found the idle is controled by the ecu and can only be altered at the dealers.

Im now wondering what sensors come into play for the idle control. It s seems to have picked up a bit now the weather has warmed up a bit. Im wondering if there is an air sensor that needs a clean / changing. Does anyone kow where the air temp sensor is?

Thanks

[Guru]

Hi,

This engine has two Intake Air Temperature sensors "IAT":

IAT Sensor 1 is integrated with the Mass Air Flow "MAF" sensor which is that Siemens square sensor on the pipe leaving the air filter box.

IAT sensor 2 is in the intake mainfold, made out of green plastic, this one can get really dirty being situated in the intake mainfold "prior to that triangular shaped plastic cover covering the engine "just above the throttle body if you have a >2006 model"

[s40_kid]

Originally Posted by Guru

Hi,

This engine has two Intake Air Temperature sensors "IAT":

IAT Sensor 1 is integrated with the Mass Air Flow "MAF" sensor which is that Siemens square sensor on the pipe leaving the air filter box.

IAT sensor 2 is in the intake mainfold, made out of green plastic, this one can get really dirty being situated in the intake mainfold "prior to that triangular shaped plastic cover covering the engine "just above the throttle body if you have a >2006 model"

The IAT on the manifold was caked in crud so gave a squirt with brake cleaner to clean it up. Revs haven't changed unfortunately. With the MAF unplugged it wont rev so dont think its that... with IAT2 disconnected its no different... thinking the only way this is gonna be sorted is a trip to the dealers. Not sure my indy garage will be able to alter.

Strangely enough when the AC is on the revs increase slightly to around 850 but drop to 800 when off. i didnt think the difference would be so high. Does anyone else's revs change as much with AC on/off?

[Guru]

Originally Posted by s40_kid

The IAT on the manifold was caked in crud

Then everything prior to it will be covered with crud too, check the inside of that aluminum? pipe from the EGR valve to the intake mainfold, if you find the inside of it to be baked too, then it's time to pull out the entire EGR assembly and clean it, you may have the valve stuck half open due to this gunk.
The pipe is fixed in place by two bolts on each end of it + one screw holding a clamp with the transparent fuel line, very easy to dismantle, see pic.


What it may look like on the inside> very scary


Another reason for low/oscillating revs: A faulty generator/volt regulator crossing the limit and producing a higher than normal current. I think it should produce a stable 14.7V output?? or was it 12.7V? you'll have to verify that figure. anything higher than normal and the ECM kicks in to lower the current by lowering revs.

As for the A/C, yes, a 50 rev increase seems to be just right with the A/C engaged.

[pukka]

whats the best way to remove the crud from the pipe? and also the ERG?

Thanks

Paul

[s40_kid]

i had the alu pipe off today and there was a build up of crap arounf the end but nothing major. Im not sure how I would get the egr valve off as its pretty tight back there. Is there any way I could test the operation of the egr valve without having to remove it?

[Clan]

there will be a fault code stored if the egr is playing up ...

[s40_kid]

thanks clan. think im going to have to invest in a DIY OBD2 code reader. Can you recommend one?

[Clan]

Afraid not , there will be others along late rwho have used one with an answer i'm sure ..