I've been searching the forums and reading about all sorts of idle problems people have (mostly with 99's), but nothing like the one I've been having with my 2003.

After the car heats up for a lil while and i drive it, if for any reason i idle for more than a min or two, whenever i begin to drive my idle rpm goes up. I will be idling at 1500 if i take my foot off the break after a red light. If i accelerate back up to 40ish for even a couple seconds it will stop and start to idle back at 750rpm

No check engine light,no missing coolant or oil,and its only after i drive it then let it idle


I was thinking of checking out the EGR ports and valve?

What do you guys think?

 

Sounds like it needs the Idle air control valve cleaned out, also check throttle cable adjustment and throttle plate for gunk.

 

^ this.. Exactly I was thinking of replying. Sounds like perhaps the throttle cable or the butterfly sticking

 

Thanks, ill look into that. Im going to check my ergs anyway just because its simple, and why not just clean out the manifold a lil. Would it just be easy to clean the idle air control valve at the same time?

 

every video ive seen with someone with an idle problem that was fixed by cleaning the iav was a different problem than I'm having. I mean while I'm taking it apart ill do a thorough cleaning and do that too, but the rpm bouncing up and down isn't whats going on.

 

Make sure to put the top plate gasket back exactly the way it was, if you flip the gasket when installing it will cause misfires when the egr starts working.

 

I had something similar a little while back. I had surging rpm while in neutral and high idle when stopped. Seemed like I was hitting the gas and brake pedals at the same time. It was the IAC for me. Haven't taken it off to do a full cleaning yet, but spaying some deep creep inside cleared things up for me for now. Just need to find the correct bits to remove the actual valve.

 

I used brake cleaner since I couldn't get one of the 2 screws holding the IAC down and that worked for me, engine was off of course.

 

The best time to do your IACV valve is if when you remove the throttle body. Most like likely you can just clean the valve without replacing it. If the EGR ports are gunked up than most likely the IACV, EGR valve and throttle body need attention.


Throttle body springs should also get cleaned with deep creep or equivalent not WD40. Than use a quality good cable lube to finish the job.

 

Thats exactly what mine feels like. A little bit of a accelleration even when im braking. So perfect ill just do it all at once.

 

Okay so i finally got to changing the idle air valve. ( mine didnt look like it was gunked up so i didn't even bother cleaning it first) No progress at all. I cleaned egr ports, egr valve, upper manifold, and the entire throttle body, but I'm still having issues.
Any more ideas guys?

I know there are so many threads on this out there, but i feel like ive covered everything ive read

 

Is not even possible to drive at 40 at 750RPM thats like if you were in Neutral.... Could you elaborate on ^ this?

 

I meant the problem would go away if i start to drive for a few min up to highway speeds. So when if stop after that drive it would go back to the normal 750

 

if everything has been replaced and double checked as u mentioned i would suspect u have internal engine problem possibly bent valves in either one of the cylinders or somethings wrong internally. i would recommend doing a leakdown and compression test..good luck!

 

im really hoping thats not what it comes down too!!!!!

 

Could you try to make a video of the problem? It will help us out in a big way..

 

Have you checked the pcv valve ?
pinch hoses around the manifold while the idle is high to isolate the issue.

 

I actually think i just figured it out, however ill confirm tomorrow. I hear a whistle that seems like a vacuum leak from near the pcv valve, but i wasn't able to pinch it off in time since i had to take the engine cover off to get to it.

The problem happens so intermittently that its hard to try some of these diagnostics before it'll stop. Tomorrow i will try the spraying carb cleaner on the area method and see how it goes

 

Ill also try to take a video tomorrow

 

One more thing i should probably mention that leans toward vacuum leak is that using a blutooth scanner and toque app, it showed normal fuel trim, then when the idle problem occured, it was running lean

 

What were the fuel trim percentages ?
mine is at 2% to 5% and no issues.

 

1.5ish when its idling funny. 4ish when not for me

 

Ive been reading that the PCV valve can create a vacuum leak if theres a problem with it, and to test it the service manual says to pinch the tube and it should start clicking. Mine clicks all the time. What do you guys think?

 

PCV is only a couple bucks might as well replace it.

 

Okay. I ordered one and well see what happens. Could a bad mount cause a leak tht could cause this?

 

from reading on here, the motor mounts can cause a leak if they are damaged.

i'm still trying to figure out an idle issue on my end, freaking TL is so sensitive, but i've replaced alot of parts and gaskets and am still having the issue. I'm gonna be pissed when its something extremely stupid......

 

Well mine just decided to continually start and stall tonight. Followed by running at about 2000 so i think its safe to say i should bring it to a mechanic.

From what i read on your thread you were pretty thourough with what you replaced. Im afraid the same thing is going to happen to me!

 

With all the starting and stalling.....is the CEL on ?

Recheck any recent work done. Try checking the codes. Make sure that your coolant is up in the rad.
Have the cooling system and fuel pressure checked. If all else fails, have the motor's compression tested.

 

So i brought it to the dealer i work at and the master technician im friends with looked at it for me and within an hour he called me and said it done. Ever since no problems, but because he needs to mess with me alittle he wont tell me what he did. Ill let you guys know when he tells me-_- no parts involved though and it was quick

 

Glad to hear. Waiting on what the problem/fix was.

 

This is going to sound really stupid, probably because it is.

I checked under the hood and the only thing i can tell that was different was that my cruise control line is cut... Yes cut.

I guess maybe the cruise control was acting up and that was causing it?

I dont use it because i live in the city but i would be pretty pissed if i used it all the time

 

Probably the cable was never cleaned and lubed so it got stuck leaving the throttle open.
A scan tool would of shown the throttle position higher than 9.4%

 

I checked at it was at 9.4 which is why this was a shock.

 

so what was the actual fix ?

 

didn't get a chance to go in and talk to him yet. All i can see is a cut cruise control throttle cable, so I'm going to assume that was my issue. Ill post what he says when i talk to him because I'm curious why he could just either disconnect, or remove it all together and not just cut the line.

 

funny that i was on that side of the engine the other day and from looking at all the OEM diagrams i was like oh thats the cruise control box and was able to turn the nut that the cable is attached too but didnt think anything of it. Let me know what he tells you!

 

Cruise control cable causing idle problems? If that guy/friend of yours cut the cruise control cable to fix an idle problem, He could of easily removed the cable from the TB without doing that. I would first get him to repair the cable. Then I would find somewhere else to bring your car.

 

Pulled the cruise cable off the throttle body and nada still did the up and down for me.

 

Nicks2001tl: Im aware of how stupid it sounds to cut it, thus why i emphasized it in the post, also if you read up i mention that i work there, so its easy to get done.

i Still haven't got a chance to head over to the service dept., but I'm still having no problems at all so thats reassuring. Sorry for the delay

 

waiting.....