4.5L D-4D idle issues (or normal?)

[JimXms]

I've only had my LC200 for a couple of weeks so I have no idea if this is abnormal for the LC200 Diesel or not..

Basically when my truck is idling (either in Park, or Drive - but stopped with my foot on the brake), the revs move back and forth between 500 and 750RPM.

Its not like a rough idle, its more like some sort of decision the ECU is making as when I come to a stop the idle will be bang on 750RPM. It will sit there for about 30 seconds, and then it decides to drop to exactly 500RPM. After another 10 seconds or so it will bump back up to 750RPM.

It doesn't really have any adverse effects other than being annoying. Also sometimes when I have the car stopped with just enough brake pressure to hold the car at 500RM, it will sometimes overcome the brakes and edge forward when the idle rises to 750RPM.

I've also noticed that if i press the "Power Heater" button it will more often than not resolve the erratic idle.

Has anyone heard of this before?

 

[Markuson]

rev variations are normal in just about every auto I,vec ever owned. AC compressors turn on and off constantly, asking for more power when they do. Other pumps turn on and off, or faster and slower. Heck, if I'm running my inverter for house current power, idle fluctuates a bit.

I would imagine its not terribly different for your diesel...but I'll leave any definitive advice to mechanical minds greater than my own (which would be just about ANY mind...

 

[JimXms]

I understand what you mean, and I've seen fluctuations in idle before when AC kicks in, but it's normally a very minor change (maybe 50rpm) in all my petrol based automatics.

I've also tried switching the AC off and it hasn't made any difference in this case.

My cruiser is still under warranty so I'd like to know for certain if it is normal or not so I can take it in to Toyota armed with some evidence

 

[Markuson]

Ah.

I guess if it were me...I would simply let them witness it...or...take out my phone at home and video it happening to show them later.

Never hurts to ask.

Toyota has an unbelievably good track record with their Land Cruisers, and if something is truly wrong, they'll help you.

 

[mark71]

Or you will get a "technician unable to duplicate customer's concern" when they don't want to be bothered.






Sorry, still pissed over my last attempt to get my local Toyota dealership to actually diagnose and fix a problem. When will I ever learn?

 

[gaijin]

I've also tried switching the AC off and it hasn't made any difference in this case.

Do you have the cool box in your center console? If so, you must turn that OFF also or the AC will not truly be OFF - even if you turn it OFF on the console.

HTH

 

[Locked79]

Yep its the AC. All the 1vds do it.

 

[Tapage]

Yep its the AC. All the 1vds do it.

that much .. I mean I've seen 100 rpm difference .. but 250rpm seems to me a lot, and much more in a V8 turbo diesel .. ( with all the low end envolved )

 

[Locked79]

that much .. I mean I've seen 100 rpm difference .. but 250rpm seems to me a lot, and much more in a V8 turbo diesel .. ( with all the low end envolved )

Yes it is a lot. I personally think there is no need for it