so for a while now i have been iving with it, but now i gotta fix it. when i turn on the ac or heater, it causes the idles to jump up and then down to like 500 rpm and almost wants to stall then jumps back up to 1000 rpm and so on. any ideas? don't know if this is it, but a while back the climate control settings broke- air ONLY comes out the defrost and not the dash or floor. i think the switch is broke, but the dealer wants to charge like 300 for the new assembly. any idea on both. HELP!

 

Idle...maybe check for vacume leaks. Check your vacume hoses in the engine bay and make sure none are torn/wore out.

For a new climate control your best bet would be to check part outs here from EVO's/Ralliarts/and Lancers to get one cheap.

Also try http://www.car-part.com/ You can check out TONS of used stuff for our cars.

Good luck

 

will do that today. thanks. any chance it could be the coil packs or something funky like that

 

Doubt it would be the coil packs/plugs. If that were the case Idle and driving would always be crazy

 

ya i just changed the plugs and wires. i also have a rrm piggy, header and intake. i know the intake is a little dirty, but not too bad. did not see any vacuum leaks btw

 

if it is not the intake and not any vacuum leaks, i would then look into the EGR valve or the IAC. a sticking valve can cause what you are discribing. and over time it will likely get worse. Generally this problem occurs in the colder months because cold conditions are hard on the valve spring. So it likely stick gradually longer over time. eventually your car will completely stall. Another dead ringer for this is if you notice strange loss of power when you are costing below 60kmph. Mostly happening when the car is still relatively cold. you should never have any problems driving at higher speed, because the valve isnt actively actuating at highway speeds.

If the valve is in the incorrect position, open or closed at the wrong time, your engine will not be stable.

I am jumping a bit into the future with just one possible answer. but if its not your plugs and wires and ignition system. your intake and throttle system may be the next place to look.

hope that helps. pm me if you need more help

 

Iac valve all the way, the computer sends a signal to the iac to up the rpms for the drain on the engine when the steering wheel is turned or when the a/c is on ...

The iac has a predetermined position in which mitsu builds into it , when it senses a drag on the engine the computer sends a signal to the iac to kick up the idle opening the valve slightly ...

its the iac and its common on most mitsus including dsm's and especially 4g63t dsm's

Mitsubishi cant design an iac with a metal tip for some reason, therefore heat and poor sealing effect it over time along with weak motor windings that of which you'd find in a radioshack remote control car motor...

the dsm's have no return circuit for the iac, meaning it wont throw a code for it the computer puts out where it should be given the voltage and coolant temp if it doesnt hit the target rpm the computer doesnt see that

 

sorry but what is an iac?

 

Idle air control=IAC mounted on the bottom of the throttle body

 

I had an Rrm piggy that caused a rough idle but when I took it off the idle returned to normal. The problem was a combo of the timing being three notches retarded and the power wire not having a great connection. Fixed that when I went to Rrm and they even remapped due to the map being somehow off. But it runs perfect now

 

Your car is pretty old and worn. Could be a lot of things. Check relays related to heater stuff too.

ROAD/RACE

 

the 1st part of that was kinda rude tbh, Not pickin a fight but maybe he takes exceptionally good care of it..

 

the car is in good shape especially for just hittin 100k miles. oh and btw rock those damn headers yuo sold me won't pass visual inspection at the smog station (those bastards) n they even said it passed but wouldnn't give me the certificate due to the visual...