engine idle is way too high?

Hello,

Its sounds like you have a piece of carbon stuck in the idle air control valve. Here is a guide to show you how to clean it and get back on the road. This is a common problem with Toyota.

https://www.2carpros.com/articles/throttle-actuator-service

and

https://www.2carpros.com/articles/engine-idles-too-high

Please let us know what happens.

Cheers, Ken

Hello:

1996 Corolla DX 1.8L 7A-FE, 5 speed, 197,466 miles

Idles correctly during warm up, but after warm up drops only to 1100-1200 RPMs. Oddly, less than .5% of the time, it idles correctly after warm up for short periods of time, almost always in warmer weather.

1. Cleaned the throttle body
2. IAC working (applied 12v - opens and closes freely)
3. Cleaned IAC thoroughly
4. Throttle cable tension correct
5. Operating temperature correct
6. Runs perfectly

Any suggestions?
Thank you.

Here is a diagnostic walkthrough for high idle. Just follow the link below;

https://www.2carpros.com/articles/engine-idles-too-high

I have a 1996 Toyota Corolla. I have a problem with it idling too high. When the engine is warm, it still idles around 1400 rpm. I read that this can usually be solved by cleaning the IACV, but I found that after I cleaned it, the problem still persisted.

I tried unplugging the MAP sensor as well, and the idle dropped while running. I just wasn't sure if this meant the MAP sensor was bad or if it was a normal occurrence. What else can i do to further troubleshoot this problem?

I love this site!

when did this start? i would clean/check IAC valve as that is the air supply for idle. any vacuum leaks can cause high idle also.

The car has idled high as long as I have owned it. I bought it used back in the summer and it has done it ever since. I cleaned the IAC valve and it didnt seem to change at all. What is the best way to check for vacuum leaks?

you can do a visual for broke/split cracked/loose hoses. you can spray a flammable substance like spray start around gaskets and parts to see if engine speed increases. you can do a smoke test and watch for smoke to be sucked in to leak. also IAC valve may be bad so cleaning it dont help.

As suggested, I replaced the IAC valve and the idle improved dramatically. Now it idles high for 5 min or so when cold and around 1100 when warm, much better than the 1600-1800 it had began to idle at.

This car has had a high idle since I bought it. I bought it at an auction, and it has had that and a check engine light since I bought it. The vacuum lines are good and I have installed a new IAC valve. Both of the diagnostic ports on my car do not connect with the engine scanner when I had it checked, so I can’t see what is causing the check engine light, and if it has anything to do with the high idle. I got a MAP sensor at a junkyard, which lowered the idle significantly, but caused the car to feel as if it was bogging or holding back, if that makes sense. At this point I’m thinking it may be a wire shortage. Any thoughts?

Hello,

Is the Malfunction Indicator Lamp (MIL) or "check engine" lamp illuminated? If so, could you please pull the Direct Trouble Code (DTC)(s)? You will need a code for that and I have included this link below for you if you are unfamiliar with how to do this.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Please go through this guide, if necessary, and get back to us with what you were able to find out.

Thanks,
Alex
2CarPros

The check engine light is on, but it doesn’t scan. I’ve been to O'reillys and a few other local places that have scanners, and they don’t connect with the car.

Hello again,

Here is what I was able to pull up on your vehicle's Data Link Connector (DLC). The DLC pins are standardized as per OBD2 regulations on every vehicle, so use the wiring diagram that I have included in the diagrams to see where the pins go to on the DLC. You will be looking for an open or for high resistance on one of the circuits. You will need to use a multi-meter to do this and I have included this link for you if you are unfamiliar with how to use one.

https://www.2carpros.com/articles/how-to-use-a-voltmeter

Please go through these guides and get back to us with what you are able to find out.

Thanks,
Alex
2CarPros

i have a 1995 toyota corolla and it has a very high idle when starting i have replace the idle valve and the tps sensor i even had my "service engine" light check but it doesnt say anything about it what else am i missing?

It is equipped with a cold start to increase the idling speed when engine is cold. How high is the starting idle speed and after warming up, what is the idling speed?

its pretty high even after its warms up but it clams down after im in gear

Either there is a vacuum leak after the throttle body or the IAC is not working correctly. It could be stuck open more than it should and how high is pretty high?

really high ive had it measured; it reads ova 2000 hpm but when its in gear it read inbetween 900 to 1000 hpm

You need to have the IAC inspected if there are no vacuum leakages. Did you check the PCV ?

pcv valve has been replace

Have you checked the IAC?

no havent had it check

Do so. That is the main component for controlling idling speed.

Engine Performance problem
1993 Toyota Corolla 4 cyl Front Wheel Drive

I repaired a blown head gasket & replaced my batt. in my 1993 Toyota Corolla & now when I start eng. it revs up & down continuously.Why?

Check and test the idle air control valve,EGR valve, throttle position sensor and airflow meter and also look for vacuum leaks

I would do as Raz said, but I think you most likely have a vacuum leak.

I would also recheck the camshaft timing, rotate to TDC #1 and check alignment marks on camshafts.

Hi 2carpros team,

I have a 93 corolla with 4afe engine, the idling speed is too high at 1400 rpm with aircon off. But when I turn on the a/c the rpm drops to 1000 rpm.

I tried removing and cleaning the whole throttle body together with the IAC valve, reset the ECU and still I got a high Idling.

I hope you could help me on this as your team usually do.

Thank you and more power!

If IAC is working properly, it could be a timing issue, but more likely you have a vacuum leak in the system.

You will have to check all the vacuum lines, they nay appear OK, but have small cracks, and generally on a car this old they are brittle.

Hi mmprince4000,

I checked and replace all the hoses that is connected to the vacuum lines and when I test drive the vehicle, the idling went to normal again and twas great! and I observed that when the engine is cold and I start the engine the RPM level is normal, but when I push the gas pedal and the engine revs up and the rpm level goes down, the rpm level stops at 1400-1500 rpm, and when I drive, the RPM is normal again...it only happens when the car is in stationary.

Do you think there are still leaks in the vacuum? Or when I cleaned the throttle body I should have replaced the gaskets?

Please help me again.

Thank you so much.

Hi,
I have recently taken my corolla to an auto expert as it was runnning rough. They discovered that the points were not set properly, and the auto choke had a problem and they also changed the belts (timing and drive). But when I picked it up it bunny hopped badly so I took it back to them and they discovered the vacuum advance hose was off. This done the bunny hopping stopped and it ran ok but now it idles at 2000 rpm on start up and a little high in general too. My questions are will this harm the car? Should I just leave it? The fuel consumption has risen greatly. Can an average person adjust the idle and where is the screw situated if so?

Hi violette2,

During cold start, the auto choke would increase the idling speed and it can reach up to 2000 rpm depending on the weather. That is normal but itr should come down after a short while and if it does not, either the autochoke is bad or the idle speed is not adjusted correctly.

Does the idling speed lowers once the engine has reached operating temperature?

You should not attempt to adjust the idle without understand what is causing it first.