Idle Level Question

[grizzly56]

I'm new to Toyotas and 200 series land cruisers. I bought a 2019 earlier this year and I've noticed now that the AC is on full blast all the time in Texas that my idle (when in park) varies quite a bit to a low of 600 rpm when it appears the AC compressor is resting/off to a high around 750-850 when the AC compressor is on. It will kick up and down fairly regularly when idling and mainly stays at the higher level. Is this normal operation for these things? I'm wondering if something needs to be checked out....it just seems to be wasting my precious $4+/gallon gas kicking higher like that.

In my current/prior GM vehicles they remained around 600 rpm regardless of AC on or off. You'd just hear the engine under a little more strain when AC was on vs. off...same RPM.

Thoughts?

 

[TeCKis300]

I'm new to Toyotas and 200 series land cruisers. I bought a 2019 earlier this year and I've noticed now that the AC is on full blast all the time in Texas that my idle (when in park) varies quite a bit to a low of 600 rpm when it appears the AC compressor is resting/off to a high around 750-850 when the AC compressor is on. It will kick up and down fairly regularly when idling and mainly stays at the higher level. Is this normal operation for these things? I'm wondering if something needs to be checked out....it just seems to be wasting my precious $4+/gallon gas kicking higher like that.

In my current/prior GM vehicles they remained around 600 rpm regardless of AC on or off. You'd just hear the engine under a little more strain when AC was on vs. off...same RPM.

Thoughts?

Idle targets on modern cars are set in the ECU. No real "tuning" or mechanical check out will generally change this behavior.

 

[stonepa]

Sounds normal to me. That being said, how much idling are you doing? Just waiting for the kids at school or long term idling? In my experience, idling uses an insignificant amount of fuel compared to actually driving my 200.

 

[grizzly56]

Not long lengths of idling or anything, just normal stuff. The idle rpm just seemed a bit high to me coming from GM vehicles and I was curious if it was normal or not.

 

[2021 LC200]

Related to this aspect; I have noticed the same and do not like the way this big V8 is managed by the engine ECU. It seems to affect how it handles idle when the cooling fan and/or AC kicks in to how the cruise control handles speed and engine revs to coming to a stop at a traffic light and the brake vaccuum booster change its boost, requiring extra break application. A bit of a basic experience. I have gotten used to it and accepted this "glitch" knowing that this Land Cruiser is sold and kept for many years/high mileage in hot middle east climates so Toyota did something right...Maybe it is all done to prevent any loading on the engine and therefore longevity.... Otherwise the engine management in my 2014 BMW 535d (6 cylinder line turbo diesel) is a dream in comparison. Not advocating BMW's here. Know the short comings. Basically requires much more attention and fixing. I do not mind as it drives great, is a daily local drive and i can fix all myself sofar, having workshop software to access and get guided repair info. Would be nice for Land Cruiser 200 engine ECU programmers to sit down with the Germans though and get it flashed to better place...

 

[TeCKis300]

Related to this aspect; I have noticed the same and do not like the way this big V8 is managed by the engine ECU. It seems to affect how it handles idle when the cooling fan and/or AC kicks in to how the cruise control handles speed and engine revs to coming to a stop at a traffic light and the brake vaccuum booster change its boost, requiring extra break application. A bit of a basic experience. I have gotten used to it and accepted this "glitch" knowing that this Land Cruiser is sold and kept for many years/high mileage in hot middle east climates so Toyota did something right...Maybe it is all done to prevent any loading on the engine and therefore longevity.... Otherwise the engine management in my 2014 BMW 535d (6 cylinder line turbo diesel) is a dream in comparison. Not advocating BMW's here. Know the short comings. Basically requires much more attention and fixing. I do not mind as it drives great, is a daily local drive and i can fix all myself sofar, having workshop software to access and get guided repair info. Would be nice for Land Cruiser 200 engine ECU programmers to sit down with the Germans though and get it flashed to better place...

Not discounting your observations. Just wanted to point out that the brakes are not vacuum driven like cars of yore. The accumulators are electronically driven with booster assist from the integrated ABS system. Highly unlikely any engine RPM related behavior could manifest in varying brake effort. I've not driven the 8-speed and my 6-speed doesn't demonstrate these symptoms, but what's more likely is the transmission/torque converter playing on brake effort.

 

[2021 LC200]

Not discounting your observations. Just wanted to point out that the brakes are not vacuum driven like cars of yore. The accumulators are electronically driven with booster assist from the integrated ABS system. Highly unlikely any engine RPM related behavior could manifest in varying brake effort. I've not driven the 8-speed and my 6-speed doesn't demonstrate these symptoms, but what's more likely is the transmission/torque converter playing on brake effort.

As always TeCKis300, appreciate your insights and knowlegde of our 200 series. Thanks for pointing out, must say have not looked at how the brake system works in any detail and whether this is in fact the 8 speed auto gearbox. I do recall this symptom though of engine rev dropping at the traffic light from around 900 to 600 rpm at which point I sometimes need apply a little more brakes to stay put. Must say, I am going to watch it some more during my next drives to confirm what I am claiming here, then think some further as to the cause.