yesterday whilst driving home the idle shot up to bout 1800. i dont know why i had this problem about 2 months ago and i installed a new isc. then the problem fixed itself. i also had tested the tps. the tps is not giving me what it should. it starts at 3.4V no throttle and then goes to 0V at full throtle.:nuts: i moved the tps and the idle droped a little bit but even with the idle screw set to minimum revs it still is at 1200 when warm.

can anyone help? i was going to take it to mitsubishi but i doubt they will help me for free as i am a struggling tafe student.

Was the ISC you replaced with brand new or 2nd hand?

You're in a second gen right? I think Magnas are great cars but these damn idle problems are really getting me down. I get the impression that this sort of issue is reasonably common in cars these days (I think falcons get them too) now that fuel injection has taken over and fuel injected cars are starting to get to the end of their lives.

Makes me want a carby. My old Sigma never idled funny.

You're in a second gen right? I think Magnas are great cars but these damn idle problems are really getting me down. I get the impression that this sort of issue is reasonably common in cars these days (I think falcons get them too) now that fuel injection has taken over and fuel injected cars are starting to get to the end of their lives.

Makes me want a carby. My old Sigma never idled funny.
It's a $90 part that's lasted 15 years, i don't think it's THAT bad.

Makes me want a carby. My old Sigma never idled funny.

Mate.. you're one of the lucky ones. Years ago I had a GC Galant and LC Lancer. (These cars have a very similar carby setup to the Sigmas) Anyway, BOTH of them developed idle problems related to those stupid automatic chokes. I hate Carbys!

new isc. just did some testing it idles fine untill i hit the accelerator. it then stays at what i rev it to to a max of 1800. could this be the tps because mine gives wierd measurements. on the multimeter,.

Take the tps out and clean it up with some carb/tb cleaner. Give that a go, and report back. :)

done that already the cleaning. i even took it off and cleaned it then realined it. still the prob. its got a new connector on it too.although if you push the connector from the bottom the engine stalls. so i think the tps is stuffed internally. it wont allow the voltage to go above 3.45V so bout half throttle. it just then decreases when it shouldnt. ill go talk to mitsubishi tomoz

done that already the cleaning. i even took it off and cleaned it then realined it. still the prob. its got a new connector on it too.although if you push the connector from the bottom the engine stalls. so i think the tps is stuffed internally. it wont allow the voltage to go above 3.45V so bout half throttle. it just then decreases when it shouldnt. ill go talk to mitsubishi tomoz

Go wreckers man and get one there
Im going tomorrow so yeah if you close i can get one for ya

all the wreakers ive gone too have had them already been taken. plus want new so doesnt happen again. like when the turbo goes in:badgrin:

Hi guys
factory service manual says TPS resistance between pins 1 & 4 should vary smoothly between
3.5 - 6.5Kohms, and continuity between pins 3 & 4 throttle released, open when throttle depressed.
I've got some ISC related experience with TR, I'll bring it forward if you need it.

Good luck

just been to mitsu they said they could check everything. but if something breaks it will cost a fortune. arrrgh. me not happy

have you found out how much an new TPS is? I replaced an ISC a little while ago it only cost 100 dollars. It might be worth it to avoid paying Mitsi mechanics and parts prices.

I'd suggest looking at the ISC motor a bit more...like is it actually moving.
Should be able to hear it setting to startup position after turning off engine, and before the fuel relay clicks off, 5 secs or so later.Idle speed can be anywhere if it's failed or intermittent.

I removed the throttle body to replace the ISC motor and adjust the TPS,
refitted everything, fired it up, and the idle was far too high.

Had me scratching my head and cursing, but then I noticed that the throttle
cable was tight.....it should have a few mm of play.

Adjusting the cable (two bolts on top of the motor to the right of the throttle body
on my KR) fixed it.

Probably not what's causing your problem, but it only takes a few seconds to check.

Regards,

Hey, that's a good point.
Check the straightforward things first....and you might not have to meet the complicated stuff lurking round the corner:)

just been at mitsu paid 50 bucks to get everything aligned and the prob is the isc they say. it was bought new from bursons about 5 weeks ago. so my advice get mitsubishis ones. they cost more but are new. bursons ones are reconditioned ones.

tread carefully stereo man
I've been down this path already....early failure of the ISC indicates possible faulty drivers in the ECU.
Needs checking and fixing before putting in another ISC otherwise you'll have another dead one.I believe the majority of failures are caused by ECU defects, some fixable.
Can give you some checking info if you want it.
Check this site

http://www.dsmtuners.com/forums/showthread.php?t=116585

mitsubishi tested the car with the mut thingo and it said that the ecu was controlling the isc fine. im just gonna get them mitsubishi to do it then i get a warrenty and if it M********s up it will be replaced for free. except the cost for the ecu repair. i need the car for tafe so dont have time to say could be this check that. i need it now.

Fair point.
if you do need to do something with the ECU down the track check out repair/exchange units
I'd bet the current price for a new OEM unit would be something horrible
Good luck

it was the isc got it back from mitsu idle was fine. man am i happy. we will see if it lasts.