Hi guys, just purchased a 1996 Lexus LS400. Mostly so i could review it and flip it. But driving the car was a pleasure, ive never been in so much comfort.

Just finished putting together a video reviewing it. Im a little worried about the gas mileage. Just idling the needle went down. Im worried.

 

If your idle is down when in gear, at operating temp and stopped, turn on your headlights one click and the idle will lift to the correct rpm (6-650 or so), if it's anything like my 96. Great bandaid, try it.

*EDIT* Watched your video. Solid video, good clean work.

 

low idle is common, which can be fixed by cleaning the IACV among other simple things. my simple fix is to run the AC which automatically kicks up the idle! my 97 gets about 20-22 mpg depending on my foot.

 

Alternately, turn the lights on a single click. Less wear, same idle increase. It's working perfectly on my 96 till I can dedicate some time to it.

 

I think he's talking about the gas gauge going down, not the idle.

 

haha right! I just re read it. I do notice the needle move when in traffic, more so when the tank is half filled. I still get 20-22mpg so if the OP is getting something close to that, then I wouldn't worry as it is normal.

 

Still, I'd clean out the throttle body intake to make sure the car is easily getting the air it needs.
I wouldn't worry so much about the needle. I don't think any one is buying these for the gas mileage.
You found the reason for the purchase already with your opening remarks. Add reliability and strong performance and what else matters?
Welcome to the club.

 

Yeah, I read his post too quickly I guess. Mine too, as far as the fuel gauge. Seems to go from the halfway to quarter full mark very quickly.

 

it wouldn't hurt to check the ecu to see if has been replaced.
mystery problems, cause by bad capacitors on the ecu board.
can cause you to spend money on parts you might not have needed.

 

My idle with no accessories on is at 500 and I don't even feel it after replacing the engine mounts with Lexus ones.

I get about 18 city and 27 hwy. One things that every new LS owner should do first thing is replace the coolant temp sensor. Hands down it'll bump your fuel economy up if it's never been replaced. I got about a 2mpg bump hwy when I did mine at 253k. You can just go with an Oriellys one for 17 bucks, or go dealer for around 45. Either way, it'll make a big difference in the way the car drives since the ECU basically relies on that sensor to know if the engine is at operating temp and adjusts parameters accordingly

 

On average I get around 18.19 MPG according to the road trip app I got on my phone. The last fill up I had was 16 MPG which has been the lowest fill up I have had since I started recording with the app.