Low idle speed

[pradogam Lurker Find all posts View Profile Close pradogam]

Hi guys, I am new to this amazing forum. I have problem and would like some feedback.

I own a 2007, 120 series with a 1KD FTV engine. The problem with my vehicle is a low 550-650 idle speed without the AC on. At this speed there is an obvious rough idle which disappears when the AC is switched on.
I have done everything possible, changed all four injectors, replaced the engine mounts, changed the fuel filter and cleaned the MAS sensor but to no avail.
Is there anything else that would cure this???

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

650 is about normal, does the motor speed up when the aircon compressor starts, if not did it
used to?

By rough idle, do you mean it mis fires or does it feel harsh. If automatic, if you move it to Neutral
does it feel better?

If you put it in reverse does it feel harsh?

[pradogam Lurker Find all posts View Profile Close pradogam]

650 is about normal, does the motor speed up when the aircon compressor starts, if not did it
used to?

By rough idle, do you mean it mis fires or does it feel harsh. If automatic, if you move it to Neutral
does it feel better?

If you put it in reverse does it feel harsh?

Thanks for the response.
It is around 600 most of the time. Yes the motor speeds up when the aircon compressor starts.
It does not misfire, it just feels harsh and vibrates a bit. There is an obvious visible shake of the fender mirror. When the transmission is moved to neutral it reduces in intensity but still noticeable

The whole issue disappears completely when I press the throttle to a speed of 700 and above or when the aircon is switched on

Otherwise the engine is smooth and acceleration is normal.

tq

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

would hazard a guess and say you have the old engine mount issue, one or
both of the hydraulic engine mounts is kaput.

[pradogam Lurker Find all posts View Profile Close pradogam]

would hazard a guess and say you have the old engine mount issue, one or
both of the hydraulic engine mounts is kaput.

Rotten luck 'cos I replaced them about 6 months ago -originals from toyota. Could the rear one cause this problem? I replaced only the front two

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

No rear is passive, could be something else but does sound like the mounts.

[Steve M Addicted PP Member Find all posts View Profile Close Steve M]

Or injectors !! Friend had both mounts replaced turned out to be injectors. His was the exact same symptoms..... Cheers Steve

[pradogam Lurker Find all posts View Profile Close pradogam]

Or injectors !! Friend had both mounts replaced turned out to be injectors. His was the exact same symptoms..... Cheers Steve

Thanks Steve.

I replaced all four injectors just a month ago and all are within specs. Could it be a EGR valve issue?

[SWR Banned Find all posts View Profile Close SWR]

Gday pradogam

Could it be a EGR valve issue?

Very good chance it could be the EGR valve not closing properly and if so, this would cause poor idle & also poor fuel consumption.

There is a micro switch on top of the EGR valve which is supposed trigger an error code if this valve is sticking or not performing properly.

An easy way to check the EGR's condition is to remove the turbo inter-cooler and open the butterfly flap on the intake housing and shine a torch/light into it and see if badly fouled with a sticky/sooty sludge.

If is badly fouled i personally would remove and clean it properly. (You could spray it but then the sludge will collect in the lower part of the intake manifold and could possibly cause the swirl-flaps to foul! (Not able to close properly for low down engine torque).

ALSO! most cleaning sprays are designed to attack/break-down/dissolve oils etc which in not a good thing for your engine oil.

Cheers

[pradogam Lurker Find all posts View Profile Close pradogam]

Thanks for the info. I'll try that first thing tomorrow morning.
Cheers

[pradogam Lurker Find all posts View Profile Close pradogam]

Got an appointment to get the mounts checked as well

[Baileys Diesel Group Member Find all posts View Profile Close Baileys Diesel Group]

I'd back Skywalkerrun on this one. IF the intake hasn't been cleaned out, this is a good place to start as unfortunately the build up is not normally uniform across all cylinders... So if we clean this out (and the EGR at the same time) should have all these issues solved.

[pradogam Lurker Find all posts View Profile Close pradogam]

Thanks for the info. Much appreciated.
Will update when sorted out.
Cheers

[pradogam Lurker Find all posts View Profile Close pradogam]

The butterfly and EGR valves were OK.
Inspection of engine mounts too were OK according to the mechanic.

The idling speed is hovering around 550-600. Is there anyway I can increase it to around 700 ? Would a reset of the ECU help? If so how do I set about doing this?