my friends car has a bad idle when you turn on the car the rpm go up to 2000 and then start to go up and down on its own what could cause this?

 

IACV. Idle Air Control Valve may need to be cleaned. You could also try to bleed the air out of his radiator or it could be a air leak somewhere. I would start with cleaning the IACV.

I almost forgot... we need to know which car your friend has.

 

iacv or dirty butteryfly on the tb

 

I actually have the same problem, but i have no idea where the iacv is. any pics?

 

I have had this problem for a long time..and have done a lot of research about it. This link here has a lot of really good info. http://www.askmehelpdesk.com/cars-tr...le-177846.html

My guess would be your IACV, take it off, clean it..or just buy a new one. You can get them off ebay for like $45-50. Also check the fast thermo idle valve, its attached by a hose to the IACV. It also could be your throttle position sensor. Check for vacuum leaks! Good luck.

 

Google it.

 

Its on the front of the intake manifold, its not hard to find, just follow the 12m water hoses that warm it , it should have a Denso label on it as well.

 

IACV is located on the intake plenum, to the right and just below the throttle body, i attached a pic of the iacv. Once you see the pic you can easily identify it.

 

There is a fast idle control valve to the right of the IACV in the picture, that can do with a clean using some carb cleaner.

Quick question guys, Should the engine stall once you cover the main throttle body with you palm? mines does not stall at all and I can't figure out how its turning over?

 

I second cleaning the Fast idle valve..

Good question, i was just working on my car today and i closed the throttle all the way and it cut out. I also was working on my dad's log splitter which uses a carb. It would only run with the choke on. Whenever we opened the throttle, it would die; pretty much the opposite effect. We then took the entire thing apart, cleaned it, and it worked again. Seems like your car is running rich..

 

you gotta get a new one. they're expensive as ****.

 

I have a DA with a B16A swap and the idle started jumping from 1000 to 2500+ rpm and I cleaned the IACV and its still doing it, what should I try next?

 

**** is expensive? You must be a youngin talking like that

 

Fast Thermo Idle Valve(FITV)!! Located under the Throttle Body.

Both my F & H does it right after the swap, so I went ahead and screw back down the wax ball inside. Problem fixed!

 

I have the same problem. I have changed the iac valve actually there is two of them the one on the pic above and to the right of that one there is a cylinder looking one too. they are your iac valves also known as your idle air control valves, but that might not be he problem your problem might be your throttle position sensor because that right now is my best guess for mine. if you un plug the sensor on the back of your throttle body it should stay accelerated to about 4000 rpms and should not fluctuate up and down if it does that we have found our problem

 

i use to have this problem, its the IACV. take it out and clean it using carb cleaner, i did this and my idle went away, only that my idle was low not bouncing, do this and u should have cleared the problem..its a big change! good luck!!

 

to complete the cleaning steps, n since u already have the carb cleaner, clean the throttle body.

 

wut car does this IACV belong to?, i noticed the difference in the positioning of the hosing.

 

clean the other FIV!! if it continues its the throttle body sensor, or u may need to renew the IACV and FIV!