Reposted an updated thread as my original post was incorrect.

http://www.aussiemagna.com/forums/showthread.php?t=102031

Oxygen sensor doesn't function when cold.
How did you check the ISC? Cold idle should be 1,500 rpm or higher. What rpm does it do when cold and you put it in drive?

PS. Daughter's don't know how to look after cars, do they? Mine has my TL wagon, I pity the poor thing. lol

lol yeah daughters :( Grrr don't get me started :(

Ok, I went through the manual and checked the fixed SAS (throttle stop screw) hadn't been played around with.
Then adjusted the idle speed screw to set the idle at 850rpm in neutral.

I've only got a multimeter, not the multi use tester (never seen one lol)

I checked the APS (Automatic pressure sensor) as per the hairdryer method in the manual.

TPS was set with .55mm clearance on the SAS screw until continuity between terminals 3 and 4, then turned the TPS until it was an open circuit

For the ISC servo (stepper motor) I checked compression first (175psi on 5 cyls and 180psi on 1 cyl), new sparkplugs and leads, and after the injectors were tested then engine was ran to normal temp, and the self diagnosis port was bridged on terminals 10 and 12, and the spark cut terminal was earthed, started and let to idle to 850rpm, switched off, and set back to normal and then ran at idle for 15 mins with no change in idle speed :)

Then adjusted the idle speed screw to set the idle at 850rpm in neutral.


Ermm, yeah, nah. That is NOT an idle speed screw! lol It's the air bypass screw.

Idle speed is controlled by the ECU via the ISC, not adjustable in any way at all. If the ISC is working, the ECU would adjust the idle speed to compensate for twiddling with the bypass screw. If you can actually adjust the idle speed with this screw, it indicates the ISC is NOT working.

To test the ISC, start the engine from cold. Revs should be 1,500 or higher, then come down slowly to normal speed.
(This does not test the ISC, idle speed is controlled when cold by the air bypass passage and wax pellet.)

ISC is working if, on a hot engine:
The idle goes up by about 200 rpm if you switch headlights or air con on.
Going from neutral to drive should keep the rpm the same.
Cranking the steering wheel while stationary should up the rpm also.

If the rpm sag when doing any of this you have a dud ISC.

What rpm does it do when hot in neutral and when you put it in drive?

As for the distributor "O" ring, I have no idea, I owned a TS V6 for 5 years but never pulled the distributor cap off. A wrecker perhaps, have a look ?

Thanks, will look at that tomorrow (y)

Ok, I think I need to alter things a bit now.

This morning I started again, disconnected the battery for half hour then reconnected it and started (only with the key) and then let it idle for 12 minutes and shut it off.

Now during the idle (and afterward) it sounds like there is an exhaust valve gone, you know the constant pftt pffttt sound, but compression test was 175 on 5cyls and 180 on 1 cyl.
Idle is still slightly rough but after the 12 min idle, shut off for about half hour as I had some other stuff to do, then restarted it.

The idle (tranny in Park) only went to approx 1300-1400rpm (on the tacho), and slowly came back down to rest at 800rpm.

If I switch the AC on the idle drops slightly to around 600rpm then comes back up to 800ish, same when i move the power steering.

So it must be down to the ISC then?

Oh and all electrical contacts were checked when I first started with this, there was only one terminal out of all the engine bay connectors had a bit of green on it but that was cleaned off with GP thinners :)

In the procedure outlined in the Mitsu manual on page 13-2-38 under "Idle speed" at the bottom left of the page what I need to do now?? (below)

Idle Speed
Idle speed adjustment is controlled automatically by the ISC motor system.
The standard idle speed has been adjusted by the speed adjusting screw (SAS), by the manufacturer and there should normally be no need for readjustment.
NOTE: If adjustment is required proceed as follows:-
(1) Confirm that the spark plugs, injectors, idle speed control servo and compression pressures are all normal.
(2) Ensure that the engine is at normal operating temperature, all vehicle lighting and accessories are turned OFF and the transaxle is in Neutral or Park and .,the ignition timing is adjusted correctly.
(3) If the MUT is used, connect it to the diagnosis plug.
NOTE: When the MUT is used, the diagnosis control terminals are earthed.

(4) If the MUT is not used, use a suitable test lead to bridge terminals 10 and 12 in the self diagnosis connector, refer Fig. 54.
NOTE: Ensure you are bridging the correct terminals, incorrect terminal connections will result in computer failure.

(5) Connect a suitable jumper lead to electronic spark advance cut terminal, refer Fig. 55.

(6) Start the engine and let it idle.
(7) Check the idle speed is to specification.
NOTE: To connect tachometer. pull back boot on the power transistor connector and inert a suitable probe into the white wire terminal.
NOTE: If the MUT is used, select item No. 22 and read the idle speed.
NOTE: The engine speed may be 20 to 100 rpm lower than specified for a new vehicle (driven 500 km or less), but no adjustment is necessary.

(8) If the idle speed is not to specification, remove the speed adjusting screw sealing cap and turn the SAS to achieve the correct idle speed, refer Fig. 56.
NOTE: If the idle speed is higher than specified, even when the SAS is fully closed, check the fixed SAS (Throttle stop screw) to see if it has been moved. If so, adjust the throttle stop screw as outlined in this section. If not, it is possible that there is a leakage as a result of deterioration of the fast idle air valve (FIAV), and if so, the throttle body should be replaced.

(9) Switch OFF the ignition, remove the jumper wires from the self diagnosis plug, disconnect the jumper lead from the spark advance cut terminal.
(10) Restart the engine and let it idle for about ten minutes and check the idle speed is to specifications.

The idle (tranny in Park) only went to approx 1300-1400rpm (on the tacho), and slowly came back down to rest at 800rpm.
If I switch the AC on the idle drops slightly to around 600rpm then comes back up to 800ish, same when i move the power steering.
So it must be down to the ISC then?


Nope, those numbers tell me the ISC is working correctly. The ECU is a bit slow in compensating for any extra load on the engine, but as long as it picks up again after the initial slump of 200 rpm it is ok.

If the car is still threatening to stall when you put it in gear and try to drive off (post #1) look elsewhere. Ignition timing spot on? Any air leaks in the ducting after the MAF? No cracks or splits in the EGR rubber hoses?

Nope, those numbers tell me the ISC is working correctly. The ECU is a bit slow in compensating for any extra load on the engine, but as long as it picks up again after the initial slump of 200 rpm it is ok.

If the car is still threatening to stall when you put it in gear and try to drive off (post #1) look elsewhere. Ignition timing spot on? Any air leaks in the ducting after the MAF? No cracks or splits in the EGR rubber hoses?

It isn't really threatening to stall, it's more like a dead spot for a bit. I've found that if I press the pedal hard it sorts it out, but it's kind of scary because it feels like it will stall, then when I hit the GO pedal it takes off.

Yep, checked for air leaks with soapy water in the spray bottle. really gave each and every hose a good dousing too.

timing is dead on 5 degrees with teh timing cut thing connected to earth, when I remove it the timing shoots up for a few seconds. It shot to 15 degrees but fluctuated to approximately 17 degrees before it dropped.

I also noticed this afternoon that the exhaust has a really fuelly smell to it. (I noticed this when the daughter returned the car too though)

Led me to thinking, if the o2 sensor is faulty wouldn't that cause the ECU to inject more fuel over the whole RPM range???

Before she took the car from us 5 years ago it ran like a dream and I consistently got 600-650km from a tank full but I'm not sure what it is like now, though a short trip about 10km out the highway and back sitting on 100kmh saw it use 2-3 needle widths of fuel, which seemed very excessive to me as it hardly moved when I had it 5 years back!

Ok so last night I finally found a post about the little LED light tool thing to check the light codes, made one up and plugged it in and it just constantly flashed, the manual says "Normal state"

Not sure if the car needs to be at normal operating temps so I will check it again tomorrow after I have been out in the car :)