Diesel air intake sensor clean

[Steve Cox]

After owning this Pajero for about 6 years we are now finally heading off on a trip for a month into the outback. I'm towing a camper trailer and will be doing some sand driving so want all the power/economy I can get.
While talking to a mate he suggested that cleaning the air intake sensor with a special pressure pack can from Supacheap would perhaps give it a boost as it does get some really fine dust in there over time.
Had a look on the forum looking for this and could only find stuff for the gen 4 diesel motor. Was wondering if it is possible with the Gen 3 and if so has it been covered before on here. Cheers Steve

[Steve Cox]

PS did block my EGR off when I first got the car, don't know if this makes any difference or not, cheers Steve

[Kingbrown]

Steve,

Look for CRC MAF cleaner (spray can).

As mentioned here before, the delicate sensor elements are deep within the black tube. On no account should anything be poked in there, except for the cleaning spray.

The amber coloured bulb that's outside of the black tube is the inlet air temperature sensor and that should be cleaned with the same spray.

Edit: Just read that Gen 3 doesn't have a MAF, so I retract the above.

[Steve Cox]

Thanks for the prompt reply Kingbrown. When you say that the Gen 3 doesn't have a MAF sensor does that mean that there is no sensor at all to be cleaned? If so that could be why I'm not able to find anything on them. Hopefully someone can fill me in, cheers Steve

[fikse]

Please don't destroy your MAF by cleaning it! Mitsubishi, amongst some others use the heated tread, Karman-Vortex sensor. They should never need a cleaning.

http://knowhow.napaonline.com/know-how-notes-how-to-clean-your-maf-sensor/

[Kingbrown]

Thanks for the alert Fiske.

I do wonder though, whether a Karman Vortex sensor is used on the DiD motor.
References I've seen all relate to petrol motors where the Air Flow Metering device incorporates a homecomb structure to streamline the airflow upstream of the measuring elements. Sensing in that case uses optical or acoustic principles to measure the vortices in the airstream.

A picture of the OP's MAF sensor would help to establish what type he has.

[fikse]

Thanks for the alert Fiske.

I do wonder though, whether a Karman Vortex sensor is used on the DiD motor.
References I've seen all relate to petrol motors where the Air Flow Metering device incorporates a homecomb structure to streamline the airflow upstream of the measuring elements. Sensing in that case uses optical or acoustic principles to measure the vortices in the airstream.

A picture of the OP's MAF sensor would help to establish what type he has.

AFAIK, but I can be wrong of course, Mitsubishi use Karman on all their engines. On my '06 4M41 / 3.2 DiD it is Karman for sure :-)

[erad]

The honeycomb structure in the petrol models is there to give some turbulence to the incoming air, particularly at low air flows. This is to allow the airflow meter to give a more accurate reading. I had a LPG powered NL Pajero, and some crappy HT leads caused severe backfires, which
(a) Caused the honeycomb to collapse, particularly when the air cleaner cover was lifted off the base and then came down on the honeycomb material; and
(b) Caused the loss of a piece of the honeycomb material when it fell out on the road somewhere.

I managed to panelbeat the honeycomb material back roughly to dimensions and shape, but the missing piece I could not replace, so I made up a perforated plate to try to simulate the losses caused by the missing honeycomb. This seemed to work OK, because it ran very well on both LPG and petrol. I did this mod because a supplier in Melbourne told me that there were lots of Pajeros running around with no honeycomb at all. I wanted to get the system back as close as possible to the original design.

I don't know what the arrangement of the diesel airflow meter is, but I will check it soon with my NW diesel. Whatever if it has a hot wire sensor, I will be very careful not to touch it. I will try to clean it with some spray, but certainly will not physically touch it.

[psproule]

Per before, the gen 3 DID does not have a MAF. It runs a MAP, mounted on the firewall behind the intake and fed via a short thin hose. This sensor should be left alone. On high mileage examples with EGR enabled, the port into the manifold might get restricted, but this was more of a problem in the NS pre manifold recall.

Pat

[Steve Cox]

Thanks for that Pat, looked on youtube as well and can't find anything for my model/motor so was starting to draw to that conclusion. All running fine, so the old saying "If it ain't broke, don't fix it" comes to mind. Thanks to one and all again, cheers Steve