You got it in one go Drover, No need for pictures, that butterfly is solely for the EGR, has nothing to do with how far you've got the go pedal pressed, Diesel's suck full air

Thanks mate this is as detailed as it can get and no need for pictures. Cannot be more easier described than this.

Do fully understand the operation of this part too now and the difference of throttle bodies between petrol and diesel is clear too.

I think with all our discussions here we have really got to the bottom of this issue hopefully. It really cannot be something else - if it is I will have a spare throttle body for sale one day lol!

One question though how does one detach the temp sensor? Is it just a matter of unplugging it from outside the unit leaving the sensor bit inside and replugging back to new or the whole sensor needs to be reused? Does it have a screw or just squeeze out type of the thing?

Just unplugging the lead, I haven't had a fiddle with mine as yet, prefer to " If it ain't broke leave the bastard alone ", anyway most of these connectors have a locking tab to move before you can pull the plug apart, of course they are not all the same so require a close inspection of each one before giving a tug..........

Yup for sure I wouldn’t touch it if it ain’t broke too!

Cool I will have a look at disconnecting the sensor first as that is the only electrical thing to be done on the process.

So I finally got the courage to give the throttle body another look at home. Took the hose off like a pro and then setup my phone camera to record the butterfly flap movement while I cycled the ignition from off to on and off without starting the engine. Uploading the video here so you guys can have a look and hear it working.

First off I can say the very little spraying the other mechanic did in a rush really didn't clean jack shit. The flap is full of oil and you can see bits of soot or whatever is all around the thing. Somehow the flap does its closed and 180 degree open position without fail. So, the default position is open. When you shut the ignition to off, it closes and opens about 4 times and remains open. You can hear the actuator/motor buzzing the whole time working to close and open the flap. It sounds like the brushless RC truck motors I had on my hobby trucks years ago. I touched the flap and checked to see if there is any play and absolutely nothing. Its rock solid so hard to say a tooth failure. Only thing I notice is when switched off an after it does its 4 times open close movements and when the motor finally stops buzzing, there is a small jerk on the butterfly and wiggles a bit. You can see it on the video. Wonder if this slight position is enough to through the code. But overall, it opens and closes quite well.

On the other hand, I have Jscan monitoring the flap movement and in my tests didn't go into error positions and worked correctly. But few days back when I did monitor it, it did say position error and the actuator motor voltage was at a high value, almost like it is trying but the flap didn't move right. But great I could monitor this live now. So whenever at ignition (without starting engine) you keep the Jscan reading live, you can tell if the throttle position is correctly reported or not before starting the engine. If the position was sensed bad, CEL on dash.

Definitely going to buy a throttle intake cleaner and give it a good clean again myself this time. Difficult to clean the flap's body because it doesn't stay closed at all..except for when shutting down it does the open close movements.

Wonder if any of you have seen this work just to compare and see if mine is doing it same or something is not right.

https://1drv.ms/v/s!Ap_EJv8kfE9c1CdR...nRaTZ?e=Txci0r

https://www.ausjeepoffroad.com/forum...0be49061a3.png

https://www.ausjeepoffroad.com/forum...0be6dddf30.png

That actually looks pretty clean considering, movement looks good to me ........ so now seems to point to a possible electrical contact sort of thing ............. Your learning as you find your way to clear a problem.... You won't get rid of the oil it will always be there, even with a catch can fitted but a clean will clean out any accumulated crud..........

If your going to use a Intake cleaner use something like Liqui-Moly Diesel Engine Intake Decarb inject it somewhere like the intake from the PCV then it will do the job but follow the instructions it isn't like giving things a squirt with WD40, needs to be done properly to do the job.... CRC, Penrite, LquiMoly all have a version.

Yea I agree it’s looking more like an electrical thing or the plate could be a mm out somewhere. Again electrical. My last resort would be trying the clean you mentioned and if that doesn’t help - throttle body it is.

This liqui-moly one is a two person job though someone needs to be holding the revs at 2K yeah..wonder if there is a less intense version that could help too since mine isn’t clogged up to much. I don’t think there is a point of taking the whole throttle assembly out to check the plastic gears as it feels and works nicely. It’s a small misalignment somewhere bugger!

Feels good to be able to see it properly myself and learning how this thing works though.