Good ol' idle issues (3.5 pajero)

[DRides]

this adjustment is only the first step in idle issues,
r u adjusting this with the engine running? - "Backed the speed adjust screw out until the butterfly was completely closed."???
backing the screw out will increase the idle.

it still may b an air leak or something else..
spray some sort of solvent / brake cleaner around your intake (not a lot / small amount at a time) and c if it changes the idle in any way, if it does then there is your air leak.
you can bypass your cold start 2 if you think it could b the issue.

[pjb]

Sorry, let me reword:

Backed the stopper screw on the throttle valve out, so that the butterfly sits closed against the bore.
Loosened off the cable. The throttle is definitely 100% closed.
With the brown connector grounded, and the engine running, turned the idle screw all the way in (closed?) idles at 900. Wind it all the way out, idles at about 1100.
I'm pretty sure the idle controller is still regulating the idle even with the brown connector grounded. If I wind the idle screw in really quickly, the engine almost stalls, then comes back up to 900 rpm after a moment. If I wind it out really quickly, the engine revs up to about 2000 before coming back down to about 1100.

Do I need to manually wind the idle controller closed and leave it unplugged?

[DRides]

does the idle change with the brown connector grounded?
if the engine is running @ idle and u ground the brown connector pin does the idle change? (it should)
THIS MAY NOT BE THE ISSUE!! JUST THE FIRST STEP!!

[date]

I know this is a silly question, but they are easier to answer than real ones... Is there something on thee butterfly which has fallen off, leaving a hole in the blade? The reason I ask this is that my old Range Rover had twin carbies on it with little discs mounted on springs, designed to open the discs and admit air under high vacuum eg on the overrun. This was to limit the vacuum generated and minimise oil getting past the rings when backing off on downhills. One of the discs fell off and went into the engine - never seen again, but I could see where it had gone when I took the head off. With a big hole in the butterfly, the engine idled very fast. I soldered a bit of shim over it to seal up the hole. I then checked the disc valve on the other carbie and found that someone had already done it on that side, only with a one cent coin.

So, if there is something similar on the Pajero, this may be the cause for the high idle. Another cause could be misalignment of the disc, with it jamming slightly open at times. The trunnions could be worn.

[pjb]

Hey date - not a bad though, but no such thing on the mitsi throttle...
DRides: Thanks for your advice mate - been really helpful.

Grounded the brown connector while the engine's running. The idle drops a note, then after a few seconds rises back up again. When I disconnect it, the idle rises for a bit then drops back to normal.

As after a couple of weeks of tweaking and driving around, it seems like sometime it idles perfectly: about 800-900, then more if the AC or power steering is loading, and higher when the engine is cold. This might last for a whole drive (1 hour) and still be fine when I park.
Other times, it idles really low, sometime stalling. This might happen after driving for a bit, or even when starting cold. Sometimes it'll be idling low, then go back to normal.

I can't detect any leaks into the plenum.
Something loading the engine excessively?
Could I be dropping a cylinder at idle?

[DRides]

as it sounds like it an intermittent issue, I would b looking at the electrical side of things first.
check your ISC (Idle Speed Control) is working properly - (@ idle the value should be around 15 with a scan tool- engina @ NOT),
also look at the temp sender for the ECU.
there are other things it might be but look at these things first.

if it was something loading the engine excessively you should feal it while driving (down on power).
and dropping a cylinder would be a very odvious miss / rough idle.

I know i went on and on about setting the base idle, but you would be suprised how often this is the issue.
unfortunately for you it doesn't sound like ist the case this time