Hello everyone...i sold my TF magna altera to a mate of mine and now bought a TJ executive of another mate lol....but it has a slight problem....doesnt happen all the time but sometimes when i come to a stop the car stalls....it starts right back up and goes....but i notice if i put it in "N" before i come to a complete stop it doesnt stall.....anyone got any suggestions????

The ISC (idle speed controller) is a small motor that sits on the side of the throttle body. It's job is to maintain idle speed at about 750 rpm no matter what the engine load.

Your ISC is stuffed.

Remember, no engine = no power steering and no brake boost. So it can be dangerous. Fix it ASAP!

where abouts is the ISC located???

ISC is on the throttle body. I would suggest just cleaning out the throttle body and plenum first. Carbon buildup can play with idle a bit. There is also an idle adjustment on the throttle body.

Is it hunting at all?

na doesnt hunt, but when i come to a stop it starts to hunt and die....after i start it...its ok but does it every time i come to a stop drop revs to 500 then stalls....i can put it in Nuetral and it wont stall but gets annoying that at every set of lights or if i have to stop i have to put it in N then back to D to drive...

Your ISC is stuffed.

The ISC (idle speed controller) is a small motor that sits on the side of the throttle body. It's job is to maintain idle speed at about 750 rpm no matter what the engine load.

Replace it.

Your ISC is stuffed.

The ISC (idle speed controller) is a small motor that sits on the side of the throttle body. It's job is to maintain idle speed at about 750 rpm no matter what the engine load.

Don't assume it's stuffed, there are other things that come into play. Your information is also wrong, the idle is variable based on coolant temp and ranges from 1500-600rpm.

Don't assume it's stuffed, there are other things that come into play. Your information is also wrong, the idle is variable based on coolant temp and ranges from 1500-600rpm.

ISC is an obvious place to start with this sort of problem. If the idle drops as low as 500 rpm its usually the ISC. Slap in a new one and see what happens. Hot idle should be very reliable at about 650-750 rpm. I don't know what the discussion is about, just a lot of guesswork - go fix it.

Oh I get it, you're one of those people who replaces $500 worth of parts before finding a split bit of 50c vacuum hose... Start with basics (ie. idle bleed screw, check for vac leaks, and clean the TB).

He has already indicated the ISC is working (stable idle, no hunting).

Just appears to be too low.

i will give it a clean this weekend and if it doesnt fix it then i will replace the ISC and see how that goes

has the battery been disconnected recently?
I noticed in my TJ I left the battery off for a night (was installing a new stereo system) and it ran like crap for a few days afterwards. It would stall at the lights so whenever I pulled up I would put my hand on the key and hope it wouldn't stall. I took it for a long drive on the highway and came back and it was fine after that.
i read up about it and apparently it had something to do with the ECU resetting or something.

Mine idles at about 1000-1100 rpm but it goes fine. I don't want to steer off topic, but can the ISC be adjusted? Perhaps that would help the OP?

The ISC is controlled by the ECU, but there is also a "Bleed" screw on the throttle body, plus adjustment of the throttle cable on the plenum. It should idle at 700rpm when warm.

Oh I get it, you're one of those people who replaces $500 worth of parts before finding a split bit of 50c vacuum hose... Start with basics (ie. idle bleed screw, check for vac leaks, and clean the TB).

He has already indicated the ISC is working (stable idle, no hunting).

Just appears to be too low.

Nope, it's just I've been through the process a number of times and I'm just trying to save the OP some time and effort.

I'm assuming he's done the obvious things like check for vacuum leaks.

Mitsu has designed the idle speed control mechanisms to be very reliable and consistent, after all they don't want bulk litigant claims with stalled engines causing crashes through loss of brake boost and steering control.

The last statement is a dead giveaway, " Just appears to be too low." A burnt out coil in the ISC stops the ECU from bumping up the idle speed.

Once its off the car you can confirm one of the 3 coils is burnt out with a multimeter.

what do you check with the multi meter to see if it is burnt and how do you check it...i got a multimeter...what do i need to do...

OMG someone is having the same problem as me at the same time as me! we can be friends :). I have TH manual and the battery went dead over night at a friends house needed to roll start it would do that after a day of not driving and since the alternator was new when i bought it guy gave me a reciept i decided to buy a new battery. with the new battery as i come up to a stop the and put in neutral, idle will drop to just below the first line about 300 rpm and then 9 times out of 10 itll slowly climb up and down to 750 800 which is normal but the other one time itll stall.
So i took the battery out and charged overnight see how it goes. My battery was out for a long time bfore being changed so ill try what jedixo said and let you know ;)

i notice it dies more often when the A/C is on....

this is what my idle is at when the car is in "D"...is this right....seems a bit low.....

http://i673.photobucket.com/albums/vv94/sleek3/IMG_0064.jpg

Sounds more like the stepper motor, when you put hte aircon on, do the revs drop or do they steady back at base idle

Throttle cable adj is just a funny comment, I would totally ignore that one. You may need to disc the battery again, leave a while, reconnect and then start the car and let it sit and idle, dont rev it, give it about 20 mins. THis may steady the idle pattern in the ECU and assuming your ISC is fine then you may have a cheap fix.

Sounds more like the stepper motor, when you put hte aircon on, do the revs drop or do they steady back at base idle

Throttle cable adj is just a funny comment, I would totally ignore that one. You may need to disc the battery again, leave a while, reconnect and then start the car and let it sit and idle, dont rev it, give it about 20 mins. THis may steady the idle pattern in the ECU and assuming your ISC is fine then you may have a cheap fix.

I mentioned throttle cable after I seen an idiot apply from tension on the throttle cable and proceed to adjust the idle screw to counteract the raised revs...

well happens both when the a/c is on and off...just happens more when the a/c is on.....is the stepper motor same as the ISC?????

and is that the right idle that i have put in my pic???

Idle settings for 3.5lt:

In neutral, full temp - 703rpm
In drive, full temp - 625rpm
In neutral, cold - 1398rpm
In drive, cold - 1000rpm

Source: TJ 3.5L ECU Code

Idle settings for 3lt:

In neutral, full temp - 703rpm
In drive, full temp - 625rpm
In neutral, cold - 1398rpm
In drive, cold - 1000rpm

Source: TJ 3.5L ECU Code

thanks for that....mine is the 3.5lt...shouldnt make that much difference...what about when the a/c is on...i know when my clutch kicks in for the a/c my idle drops really low.....could this be the stepper motor???

also is the stepper motor and ISC the same thing???

Edited above post, those were 3.5L idle settings :P It is normal for AC to alter idle behaviour.

In my experience, when the A/C compressor cuts in, the revs jump UP a bit, then slowly settle back down.

The ISC is a stepper motor. Pulses from the ECU rotate a spindle a certain number of degrees, a plunger moves one way, which covers or uncovers an air passage.

Later Mitsus like the Lancer have sensors in the power steering and aircon circuit which sense extra load and elevate the RPM.

My simple test for a defective ISC is to get to a hot idle, and in neutral, turn on the lights, air con, and move the steering wheel to full lock (one at a time). If the revs don't go up or stay stable each time, I replace the ISC. Hasn't failed me yet. lol

but mine jumps down and not up......is this because of maybe a bad ISC???

but mine jumps down and not up......is this because of maybe a bad ISC???

Yes. Correct. Affirmative. Indeed! Truly.

There are 3 coils in the ISC, if one goes open circuit, it doesn't work.

Ooops! 2 coils. I've got one in bits and had another look.

It is not normal for your idle to go funny with the aircon on, agian this is wrong information

What should happen, when the clutch kicks in, the ecu should bump up the idle a little, then it will drop down to approx where it was before, it should happen fairly quickly so there is no other effect on the car etc. You will notice it but not by much.

The ISC is most likely the issue here

Here's a thread on cleaning the ISM: http://www.aussiemagna.com/forums/showthread.php?t=87966&highlight=rough+idle

If cleaning doesn't work, search YouTube - there is a video on checking an ISM - basically, connect voltage to the correct terminals and the ISM motor should move the plunger in and out. If it doesn't, the motor is stuffed.

Here's a thread on cleaning the ISM: http://www.aussiemagna.com/forums/showthread.php?t=87966&highlight=rough+idle

If cleaning doesn't work, search YouTube - there is a video on checking an ISM - basically, connect voltage to the correct terminals and the ISM motor should move the plunger in and out. If it doesn't, the motor is stuffed.

What is an ISM?

The plunger on the ISC used in the Magna is worked by a STEPPER MOTOR - it works only on pulses generated by the ECU. Connecting DC voltage to the terminals will do NOTHING to a working ISC, except maybe burn it out. (6 volt maximum, by the way)

The ISC connector has 2 rows of 3 pins. Each row represents the connections to one of the coils. The centre pin is a centre tap. Measure resistance from the centre pin to each of the outer pins. You should get 4 readings. They should all read the same resistance, 28-33 Ohms. No, I didn't make that up, I looked it up in the manual. (reference = section 13A)

Hey, how are you doing with this problem?
My car (which Ive only just) got is doing this too, Ive only done about 30 km in it so far.... but it is getting worse id say. Terible on petrol at idle but ok on LPG, Ive been turning the aircon off as I approach low speed intersections or have to stop just incase it stalls, it hasnt yet tho. I was expeimenting in the shed with it on idle, activate lights and power steering etc the revs drop is minimal from 800ish put the ac on and down she goes and bounces around abit leveling at like 400 ish! so I think my ISC is struggling not yet dead.... I did experiment with the SAS on the throtle cable putting idle up a bit which does help tho Im not going to entertain leaving it like that. Ill take it to Kmart auto I reckon (??!!) and explain id like the diagnotics to sus it out along with a major 180,000 km service. I spose I could get the ISC on ebay or online cheaper than they will get it and fit it but at least they should get it right - I hope and then i can call back on them if it still gives trouble? Im into doing things my self etc but sometimes you know! so let us know how you go, funny my car is great to drive apart from the idle problem so im keen to fix it . Any one know what sort of km these ISC do before they die?

ISC can last 10 years or more. Older Magnas seem to have it fail as a common problem.

When mine failed in my auto 2.6 TS I used to keep the revs up with the right foot while braking with the left foot. Takes a bit of practise though.

I don't think a failed ISC shows up on any diagnostics machine. Unless the K-mart boys have years of experience with Magnas they won't be able to identify this problem. They will probably change a few unrelated things in order to get a steady idle. You will be paying for their learning experience. See a recognised Magna mechanic instead.

ah Mitsubishi windsor gdns is looking better abd better atm, did a parts search on the number on my ISC and the number E9T15296 on it comes up on a search for a Galant e54a or e64a a 2ltr V6, the TS magna V6 lists number 9T15271! soooo do I have the wrong ISC on this car and could that be related to the idle probs? thanks for your help MadMax

Let me keep it simple:-
Step 1: Go to wreckers.
Step 2: Find a car that looks like yours.
Step 3: Take its ISC.
Step 4: Pay for it. Ask if you can return it if broken.
Step 5: Put it on your car.
Step 6: Test out.
Step 7: Smile.

Um... It happens in drive, after coming to a stop. It's worse with the air con' on... when was the last time the transmission was serviced? Is the fluid over full. If you start the car hot or cold, and it idles relatively okay (be it at higher or lower than normal revs) but only does its stalling thing when you come to a stop I'm thinking the trans' is loading things up. Either its not downshifting quite fast enough, the torque converter isnt emptying or the TCU/ECU communication is not keeping up. As in the car still thinks it needs to be in 2nd gear when you've already stopped.

I'm usually wrong, but its worth a look. I can make the four speed in my Exec get confused with hard braking (100kmp to dead stop)

Those ISC things are ridiculously reliable, heck I've even resurrected one - they just don't die so easily. I'd be checking it according to the manual first to avoid wasting time. Hell, I'd be checking everything I could before chasing the moths out of my wallet.

A wrong ISC motor would make a dramatic difference depending on the shape of it's plunger and the stroke of the motor. It would either need a whole lot of adjustment to the bleed screw to compensate - IF it would work in the wrong engine. Simple check is to count how many turns there are on the bleed screw - if its wound out more than three or four turns it could be the wroing motor. I think it only takes a three quarter turn to get the idle right (with a good ISC).

Simple check for ISC is the screw driver stethoscope trick - listen to the ISC motor directly, if you can hear it clattering away with the screw driver its good = dont change it.

If you can hear the ISC working, and you bleed screw seems right, I'd be looking elsewhere for a solution.

WAIT!! Have you cleaned the TB lately? If not, try that - give it a good clean. If you have cleaned the TB - did you get that STUPID o-ring back in between the ISC and the TB? I say STUPID because, one handed, it's b!tch to put back in.

lol The ISC will chatter even if one coil has gone open circuit, it just won't wind the spindle in or out.

Have you tried the multimeter yet? It's the only way to be sure. I went to some length to locate the information in the manual, at least you can do is use that information.

I appear to be talking, but no one seems to be listening. I'm out of here - this thread anyway. Then again I can start to suggest things it's not likely to be, like a seized up torque converter, failing gearbox, burnt exhaust valves, etc. lol

Hey all, im listening ! I just had to go to sleep last night after that post as I get up early.... I lent my multimeter to my mate last week and looking to get it back wednesday when I will test it with the figures you posted MadMax, thanks... I was thinking just buying another multi meter so I could do it this arvo but Ill pull The ISC out this arvo and clean it and TB havent even had it a week yet!. Skapper, Im pretty sure the trans isnt to blame as the idle is good in park then put the a/c on and the revs drop to like to 400 and wants to stall but fights it. Its fine when the a/c isnt on! Im fortunate I dont really need it for a fornight so Im getting on top of it this week as I have another vehicle to use.
I kinda thread jacked this from another member I appologise, but may be useful info for them here too, but maybe Ill leave it at this post, as far as my probs go, and start a new one in the relevant section in a few days when I sort it out, thanks again everyone.

I've got an eBay multimeter in the post to replace the one that self destructed with a leaking battery. I have one busted ISC and 2 from the wreckers I haven't looked at yet. I will check all 3 for resistance and post up to confirm the manual numbers - when the slow boat from China gets here.

Hello everyone...i sold my TF magna altera to a mate of mine and now bought a TJ executive of another mate ....but it has a slight problem....doesnt happen all the time but sometimes when i come to a stop the car stalls....it starts right back up and goes....but i notice if i put it in "N" before i come to a complete stop it doesnt stall.....anyone got any suggestions????

This was what I was referring to when I suggested the transmission as a possibility.

I'll quote the text and not bypass the other comments to avoid the confusion next time.

As i just discovered after Cleaning my TB and ISC Check your Battery and its voltage and to see if the Alternator is charging 13.x Volts (Mines not and is at 12.4 and i have the increasing stall problem)

I've got an eBay multimeter in the post to replace the one that self destructed with a leaking battery. I have one busted ISC and 2 from the wreckers I haven't looked at yet. I will check all 3 for resistance and post up to confirm the manual numbers - when the slow boat from China gets here.

Right! Multimeter arrived, so here goes:

Non working ISC, from TS:
One coil: 29 ohm, 29 ohm. (Reading from centre contact to each of the two outer ones)
Second coil: 29 ohm, open circuit.

Wrecker ISC, alloy body.
All 4 read 29 ohms. So it's good to go in a TS.

Wrecker ISC, black plastic body.
All 4 read 39 ohms. Might work on a TS, or is it off a third gen or something else? Can't remember car it came off. lol

Anyway, this shows the multimeter method of checking an ISC works - tells a good one from a bad one.

By the way: Same multimeter gives me 14.4 volts across a hot running engine TS battery, 14.6 volts across Lancer battery just after cold start. Why people quote different voltages baffles me. If you get 12.4 volts with the engine running the car is probably stalling because the alternator is not working and the battery is close to flat!
I tested a spare battery that has been sitting around for weeks since charging, it's at 12.5 volts.
(Yes. I like playing with my new multimeter!)

Has the OP problem been solved?
For what its worth had EXACTLY same problem with my 2.6 TR. Swapped out the ISC with one from Repco and fixed the prob straight away... of course the Repco part failed again some time later but that's another story...