Hi, I'm new to the forums and need some help. - I posted this before but got no answers.

I have a 97 TF Magna Executive Sedan (1st Mitsubishi I've owned)
Brought it off a lady who sat it in the shed 4 years ago because she had 3 other cars.

It has always been serviced and well looked after, was service just prior to being put in the shed.
She took the battery out to put the new one in when she sold it to me, and for some reason its idle sits around 2000.

I had a look on this forum and found out that the computer has to teach itself again, I did the all the procedures I could find but the car still revs around 2000.

It's automatic and when it is in a gear it drops the revs back to normal, as soon as it is in park or neutral it jumps back up.

If I could get any help at all, It would be very appreciated.

Hi, I'm new to the forums and need some help. - I posted this before but got no answers.

I have a 97 TF Magna Executive Sedan (1st Mitsubishi I've owned)
Brought it off a lady who sat it in the shed 4 years ago because she had 3 other cars.

It has always been serviced and well looked after, was service just prior to being put in the shed.
She took the battery out to put the new one in when she sold it to me, and for some reason its idle sits around 2000.

I had a look on this forum and found out that the computer has to teach itself again, I did the all the procedures I could find but the car still revs around 2000.

It's automatic and when it is in a gear it drops the revs back to normal, as soon as it is in park or neutral it jumps back up.

If I could get any help at all, It would be very appreciated.

Not entirely true, you received 1 reply , 1 question and you stated to have found the solution in post #4 and all was fixed.

http://www.aussiemagna.com/forums/showthread.php?t=103375&p=1604641&highlight=#post1604641

So from when it was fixed, what has happened? What things have you checked?

The intake air volume during idle is too great. For the engine speed to increase additional air needs to be allowed into the inlet mainfold.

You have the butterfly in the throttlebody( cable operated) , SPEED ADJUSTING SCREW (air bypass) at the top, air bypass via the ISC motor on the throttle body(electrically contolled by the ECU and a fast idle air valve (air bypass controlled by the coolant temp)., fixed speed adjusting screw (mechanical) on the throttle crank which should not be adjusted but could have been messed with.

I'd start with proving what is correct first like the closed throttle position, check correct operation and that it 's not sticking, check all vacuum lines are on and sealed, air could be entering external to the system.

ISC could be faulty and sticking open, check continuity of idle switch on the TPS, maybe try disconnect the ISC harness although I don't have a full understanding of it's operation if it returns home when the off? When you first turn the key on can you here the ISC chatter for a second or two?
Sensors that influence it's operation

Engine coolant temp sensor, could be telling the ECU the engine is cold
gear selection
A/C operation
Power Steering pump load


fast idle air valve (air bypass controlled by the coolant temp)., could be stuck open,?? never seen in one of these either but assume a bit like a thermostat and opens and closes a valve so maybe it's stuck?

Yes, I did receive a reply.
In the form of a question, about Air Conditioning. - In which I stated that the model I have does not have A/C.

The solution I discovered on another site did work. Then i swapped out the battery for a brand new one and the issue came back, and for some reason the procedure did not work the second time.
Had a mechanic look over it and everything seems to be working properly, no leaks in any hoses, all sensors working right, and when plugged into a code reader no errors appear.

It drove home fine when I purchased it from the lady, only had the issue since battery changeover.

I turn the ignition to on, (the ISC chatters)
Start car, sits at 800 for a second. Then starts rising slowly to between 2000 and 2500.
Put it in any gear (apart from 'N' or 'P') and it drops back down to 800 again.

I wonder if it's an ECU issue and the ISC is slowly being driven open? maybe you could start the car and disconnect the ISC and see if it still continues to rise in RPM. certainly an unusual fault.. I know after a battery change you need to let it idle so the ECU recalibrates the ISC.

No doubt you've tried disconnecting the battery again to tryand reset it?

Maybe you might be better off getting a dealer to hook up the MUT to it and checking it out. Might take all the guesswork out of it.