This is a generic video but should point ya in the right direction, I'm sure there is one applicable to your car out there.
Also look for vacuum leaks. Pass a propane source over the engine and see if the rpms change in any given area.

 

You can try to unhook the battery to force the ecu into relearn. See if that helps with the fast idle issue.

 

sdspeed
I've checked utube video's and couldn't find anything specific to our generation corolla. I visually checked for vacuum leaks and couldn't find any.

75 aces.
I can try disconnecting the battery and wait till it goes through the learn cycle

 

I disconnected the battery for 15 minutes, reconnected it and drove it for over a week to allow the computer to complete it's learn cycle and I still have the fast idle issues.

Conclusion: I'll just live with it.

 

According to this High RPMs at cold start your fast idle is normal. In this thread 03 Corolla Fast Idle When Cold - Gaskets Replaced &amp... it's normal too.

Edit : if you have a 5 speed manual, in the first thread, post 2 or 3 has a link to recalibration to fix fast idle for 2003-04 models.

 

Thanks for the reply 75 aces:
My problem isn't with the rpm's in fast idle per say, although it's higher then it was when new (new fast idle 1700 for 30 seconds during summer). My issue is with it going from 30 seconds for about the first 14 years and now it's 4 1/2 minutes before going to regular idle.

As stated earlier, I can't find the issue, therefore I'll live with it.

Thanks

 

if it has the original intake gasket, that needs to be replaced. the idle issues should go away once it's been replaced. i've had similiar issues with two cars and both were solved with replacing the old gasket. its a really simple easy swap. i just read that you replaced that already.. i guess see if there is still a vaccume leak there. its possible the intake may have a small crack in it.

 

Pass propane over the engine and listen for an rpm change, that indicates a vacuum leak.

 

Thanks for the reply rich_d.
In the original post under diagnostics, I stated "At 70,000 miles I replaced the intake manifold gasket with OEM material. " That procedure/repair, brought down my fast idle from 2800 rpm to 2100 rpm, but it still takes over 4 minutes during the middle of summer and still now.

Thanks for the suggestion sdspeed.
I don't have any propane around, but I did try brake cleaner when I was diagnosing another issue in the corolla, and checking for vacuum leaks and found none.

 

It's the temp sensor that detects the engine coolant temp, which brings the idle down I believe. Does your temp gauge read ok? The fact that it comes down to normal idle after 5 minutes should rule out a vacuum leak.
Is your coolant low? I wonder if that can affect the engines ability to sense the coolant temp?
You should give your local dealership 1 hour to diagnose the problem, or at least go ask them what they think.....
What did you find with the IAC?.....good luck.

 

That's for the input kevcules46.
Temperature gauge has always read in the middle once warmed up since new.
Coolant was checked 2 weeks ago and it was at the proper level.
Dealership wants $130.00 per hour (in Canada) and I'm unwilling to pay that amount, based on no guarantee of proper diagnostics in that period of time.
Dealer will not give suggestions unless you pay for diagnostics. They won't even scan for free, that's $95.00.
TPS is new denso, I've never checked the IAC. I thought IAC issues, would throw a code?

 

Yeah I hear you. I'm in NB and they want $120/hr around here at the dealership. I just thought they might be able to figure it out quickly if they saw it a hundred times before.
I would remove the IAC just to have a look and make sure the mechanism is not corroded/moving hard. I've never pulled one apart so not sure how it works. I have an 06 Corolla and haven't seen that problem before. Good luck

 

They maybe able to figure it out quickly, but car dealerships go by "Flat Rate" which means the mechanics get paid for what the Factory Service Manual/book rate stated the diagnostic should take. In other words, it the rate to diagnose the problem is one hour, if they figure it out in 10 minutes based on experience, they still get paid 1 hour. If they take longer, they still get paid one hour. That's the way most Ontario Dealerships charge.

I never thought of the IAC being an issue until you mentioned, it. I should Utube it and become better educated on how they work and or effect the fast idle.

Thank for the thoughts.