Fix for Low idling on my LX470... (1 Viewer)

[wrav001]

I had low idling (400-500rpm) on my LX470 with 160,000kms on it. Had it for 15 years and very well looked after by the agents and myself. Haven't been driving it due COVID restrictions didn't let us go far.

So here are the things I did, Please correct my Last step if I have done anything wrong.

1. New fuel filter
2. LiquiMoly injector cleaning additive
3. MAF and Throttle body cleaning
4. Ignition ON/OFF ON/OFF EM brake on calibration

Above things improved the RPM by about 100RPMs. So I was stuck at 600RPM.

Last resort I played with the Throttle Body Adjustment Screw. (half a turn and we are at 800RPM). Few experts have told me don't touch this screw. Is it OK to do so?

Now it is running at 700-800RPM and everything is smooth.

Any advice much appreciated...

 

[Chibu]

The thing with messing with the throttle body setting is that the engine will take in more (or less) air for the same amount of throttle (or lack thereof), depending on how you set it. The ECU will then try to compensate with more (or less) fuel. Which can negatively (or positively) affect fuel mileage. That's said, it's ok to touch the screw, as long as you're more experienced than my newbie self (and seeing as you went for that screw you are lol). If you're getting low RPMs at idle, the first thing to go to is air filter. Clean it; change it to be sure. Then go for spark plugs, throw all of them out and change them with OEMs. A new fuel filter is great but I would think the oil filter and existing oil should go (and be replaced) first. Throttle body cleaning was a really good call, but messing with that screw is another story. Messing with that screw should be like a last resort/I need more power faster kind of thing. Back in 2015, my (dad's) '06 Range Rover was running 400 RPMs at idle. We changed out the spark plugs and air filters and now it's a steady 900-1100 RPM idle. I would suggest valve cleaning, but you have 160k kms on your LX, and valve blockages due to carbon or other buildup problems are SUPER rare so unless you're 1000% confident, then I don't think cleaning the valves is necessary.

 

[badlander]

You may be a little high. Idle speed should be 700 +-50 while in neutral and at normal operating temperature and AC off.

 

[Chibu]

I was talking Range Rover not Lexus. And don't quote me on it, I was like 12 back then lol

 

[wrav001]

You may be a little high. Idle speed should be 700 +-50 while in neutral and at normal operating temperature and AC off.

I have adjusted it to 700rpm. Feels and drives great.. Cheers..

 

[wrav001]

The thing with messing with the throttle body setting is that the engine will take in more (or less) air for the same amount of throttle (or lack thereof), depending on how you set it. The ECU will then try to compensate with more (or less) fuel. Which can negatively (or positively) affect fuel mileage. That's said, it's ok to touch the screw, as long as you're more experienced than my newbie self (and seeing as you went for that screw you are lol). If you're getting low RPMs at idle, the first thing to go to is air filter. Clean it; change it to be sure. Then go for spark plugs, throw all of them out and change them with OEMs. A new fuel filter is great but I would think the oil filter and existing oil should go (and be replaced) first. Throttle body cleaning was a really good call, but messing with that screw is another story. Messing with that screw should be like a last resort/I need more power faster kind of thing. Back in 2015, my (dad's) '06 Range Rover was running 400 RPMs at idle. We changed out the spark plugs and air filters and now it's a steady 900-1100 RPM idle. I would suggest valve cleaning, but you have 160k kms on your LX, and valve blockages due to carbon or other buildup problems are SUPER rare so unless you're 1000% confident, then I don't think cleaning the valves is necessary.

I had oil, fuel filter changed by local Toyota Dealer about 2 weeks ago. Car has always had Toyota Original Engine Oil and had 100% original parts. US$80 for fuel Filter and US$80 for Air Filter in my country. I have changed spark plugs about 8 years ago and have only done 60,000 Kms since. I hope to change them in the near future. Engine runs very smooth so didn't want to change anything unnecessarily.
I am a big fan of LiquiMolly Valve Cleaner additive and Injection cleaner additive. They keep these old beasts running like new.. Spark Plugs still looks new after 60000kms after LiquiMolly injection cleaner. I normally pour a bottle(500ml, on 50L) every 10,000kms..

 

[Chibu]

Ah, ok. You should have nothing to worry about then. Don't mind me