i cant figure out why im idlling at 2000 rpms. any help?

mrpyrex · Post by **mrpyrex** » July 31st, 2007, 10:33 pm

my engine is idlling at 1500-2000 rpms. i had a wreck a while ago and a lot of stuff is outta wack but i had it running fine, great evan and then this started and i cant fix it. i would try adjusting the idle control screw thingy but every once in a while it will idle normally from the time i start it, till i shut it off. i would think if i adjusted it while its high, if it trys to go back to normal it would just kill the engine. but man if anyone knows what might cause a fast idle or has had this happen before i could use any help at all. thanks

Bochek · Post by **Bochek** » July 31st, 2007, 11:01 pm

stuck idle air controll valve?

or a bad temp sensor.

ModMX3 - (Carmaster2005) · July 31st, 2007, 11:39 pm

Kinda hard to figure out being as you where in a wreak it could be alot of things, disconnected vacuum hoses cracked intake mainfold 'not likley' or as Bockek said IACV Temp sensor. go through and listen for sounds of leaks like a hissing noise.

mrpyrex · Post by **mrpyrex** » August 1st, 2007, 12:11 am

huh, yea i was reading about usin a piece of hose or a stethascope to hear leaks. i guess ill give that a shot. do you know if running a diagnostic thing on it would tell the problem? i may have to it this starts getting way more complicated.where is the IACV sensor roughly? or where in the manual cause i cant find it. thanx

umcamara · Post by **umcamara** » August 1st, 2007, 12:31 am

You have to jump the TEN and GROUND pins of the diagnostic box under the hood. Then start the car and allow it to reach normal operating temp. Now adjust the idle air adjustment screw until your idle is about 750-800. Once that's set, remove the jumper at the diagnostic box, and THEN shut off the engine. If you don't jump the pins at the box, the computer will try to adjust the idle on it's own.

Hope this helps.

Yoda · Post by **Yoda** » August 1st, 2007, 12:37 pm

Sound like the connector or wiring is broken to the IAC. When this is un plugged the idle should jump up to between 1500-2000rpm. the other thing to look for is something preventing the throttle plate from fully closing.

mrpyrex · Post by **mrpyrex** » August 1st, 2007, 8:57 pm

this connector you are talking about, it isnt right next to the battery by chance. cause i noticed there is a conector stuck to something that is all cracked. i think the wires are comming off of the top of the air filter housing where the big hose runs to the engine. or from where the hose meets the engine. where is the IAC sensor? and damn you guys are awsome. thanks everyone for some fast help. thanks

Yoda · Post by **Yoda** » August 2nd, 2007, 11:01 am

The connector should be at the bottom or side of the T/B (not exactly sure for memory on the DOHC) Not the one for the TPS but one attached to the ISC solenoid bolted to the bottom of the T/B

umcamara · Post by **umcamara** » August 2nd, 2007, 5:31 pm

The connector you're looking for is on the opposite side of the throttle body from the TPS. It's towards the front of the car, whereas the TPS is towards the rear.

novafreak66 · Post by **novafreak66** » August 6th, 2007, 1:26 pm

I have a mx-3 idleing at 1500 rpm and the engine dies when the a/c comp comes on. I think its the idle air control valve, but I am not sure exactly where it is. This car has a 1.6L SOHC engine. Does coolant run through this valve. Any info will be very helpful.