I have a rough Idle how can I fix it?
Asked by Anthony Jul 10, 2018 at 12:58 PM about the 2003 Toyota Corolla LE
Question type: Maintenance & Repair
Ok, I have a rough idle on my Toyota Corolla 2003
but, only when is in operating temperature or warm,
when is cold it idles fine. It looks like the rough idle
is worst when is in reverse or drive and I'm still
when in park or neutral the rough idle is not that
bad. I have done several things to the car change
the O2 Sensors, change the gas cap, clean the idle
air control valve, cleaned throttle body, cleaned
mass air flow sensor, change intake manifold
gasket, change motor mounts, change the
transmission mount, and a few other things that I
can't remember and I still have the rough idle. I was
reading online that it can also be a dirty fuel injector
but really not sure what should I do and how can I
diagnose if it's the fuel injectors or something else?.
one more thing there is no codes on the car so
really driving me crazy. One thing I forgot to
mention when I am stoped and the I accelerate I
feel like the car struggles a little like it does not have
a lot of power.
10 Answers
firebird338 answered 6 years ago
Add some fuel injector cleaner to gas tank
Have You maybe found the problem? I have the same issue in my 2003 corolla 1.6 vvti.
Not yet some one told me it could be the motor mounts. I mention I had put new ones but he mention that it will still shake if it’s not OEM but there so expensive.
try this one: https://www.cargurus.com/Cars/Discussion-t25172_ds685517 I will try do it tommorow. Only problem is to remove old resin. The screw set up initial throttle position. Generally throttle position was adjusted about 15 years ago, engine parameters has changed during this time. That why sometimes it has bo be readjusted. I read at other websides (toyota ones) that that works.
In my case problem is solved. Before, when warm I had about 500rpm. Now it is something like 620- 650. I adopted throttle body. This is how i did it: - disconnect battery for about 30 minutes - connect battery - turn on ignition and turn it off - turn on ignitiom one more time and start engine - turn off lights, a/c and other receivers - don`t touch gas - wait something like 30 minutes untill engine is warm enought - after all turn on a/c and light wait 2 or 3 minutes - turn off engine. It should be done.
OwnerofClunker answered 5 years ago
Grzegorz is the genius of this topic. I've searched hours and hours and replaced parts and still had the rough idle. The adjustment screw was the problem. My Carolla is 16 years old so it's not surprising that the idle adjustment screw would eventually start backing out. Just a slight turn and it runs like new. Mine has the throttle cable. There is a tiny Allen head screw that you can adjust. I replaced just about everything around that throttle body and all it needed was a 1/4 turn. Oh well, it doesn't hurt to replace that stuff anyway. Thank you sir! You are a genius
Opening the throttle isn't fixing the problem, just hiding the symptom. The throttle body should be closed at idle, and the IAC ( Idle Air Control) valve should provide the air needed for a smooth idle.
Same issue 2004 corolla.. Idles fine until i put it in gear then wants to almost die. I cleaned throttle and idle control valve but didn't help. I got a scanner tool and Bam a p0505 code. So i will be replacing my Idle control valve and see if that the issue. thanks for your help.
Maybe try taking a look at the Catalytic Converter it could be that?
i have change timing kits on my Toyota corolla 2012 model but the car is falling to idle
