Faster Idle w/AC

[mrslate63]

Anyone else notice the 4runner seems to idle quicker and at higher rpm when the a/c is running? Without the a/c the transmission seems to have an almost "built in" ret@rder, requiring less braking.

When my a/c is running it takes much more brake power to slow it down and the transmission ret@rder does not seem to kick in.

I know the engine has to run at a higher rpm to turn the a/c compressor, but it just seems kind of odd compared to when it runs without it.

 

[adoihcj]

Anyone else notice the 4runner seems to idle quicker and at higher rpm when the a/c is running? Without the a/c the transmission seems to have an almost "built in" ret@rder, requiring less braking.

When my a/c is running it takes much more brake power to slow it down and the transmission ret@rder does not seem to kick in.

I know the engine has to run at a higher rpm to turn the a/c compressor, but it just seems kind of odd compared to when it runs without it.

I hear what you are saying. All vehicle RPMs increase when A/C is on, but the 4R seems to accelerate higher. One thing I've noticed is if you are at a stop and have the brakes lightly applied, when the A/C kicks on, you will move forward because of the extra RPMs. Caught me off guard one day while at a red light and almost bumped the person in front of me.

 

[Uneek]

I hear what you are saying. All vehicle RPMs increase when A/C is on, but the 4R seems to accelerate higher. One thing I've noticed is if you are at a stop and have the brakes lightly applied, when the A/C kicks on, you will move forward because of the extra RPMs. Caught me off guard one day while at a red light and almost bumped the person in front of me.

Maybe that explains some of the SUA in other Toyota models. Speculation aside...

It's a characteristic of Toyota trucks and SUVs. My 4Runner does this and my '05 Tacoma does too. Definately keep a firm hold on the brakes when the climate control is in 'Auto' or the A/C is on, when the compressor cycles the vehicle will lurch forward.

Quite a few Tacoma owners over on ToyotaNation have experienced this too and in similar situations to adoihcj.

 

[M1911]

My '03 V8 does that as well, which is why I typically shift into neutral at a stoplight.

 

[angrydog]

Just to add, my 1991 Corolla did this. Exactly what adoihcj said; if you have your brakes applied lightly, the car would jerk forward a little. I havn't had the chance to use the A/C in the runner yet so I'll see.