lexforlife

iTrader: (7)

imo its programming hole in the ecu software.. the vvti tech is constantly readjusting the valves for optimum driving but somewhere in the programming when it needs to return to idle while in drive it senses no load and drops idle below accept specs,hence driving with a/c or lights on creates a load so computer readjusts to compensate.. throttle bottle cleaning , replacing throttle body air flow sensor cleaning to me is all hopla,, its a software issue and lexus knows it but its to expensive to recall ecu's to reprogram them or outright switch them.. look at it this way as well , when we reset our ecu , does not the idle at least for the first few hours or days seem to improve ?


again just my .02 worth

GSquicksilver

i kinda agree. resetting the ecu does smooth out the idle, but does not bring up the RPM at all. the longest i've seen resetting the ecu help was probably 2 weeks in my own experience. any guys with a 2000 gs4 have this rough idle issue?

ChrisK

iTrader: (1)

Not me. It idles OK and never stalled.

gserep1

Hello
I have never had an idle problem with my car...so far. It is a 99 with 78,000 miles. It runs perfect. The response changes from time to time, depending on the difference in premium fuel at some stations. I Do notice that the idle is a bit rougher when the AC and headlights are off. The idle is less than 500 rpm in drive, and idle is about 750 and VERY smooth with the AC on in drive.

I drove from San Diego To San Francisco and back over the Thanksgiving holiday and saw 26.5 mpg on the open road at less than 80 mph. It was boring, but the traffic was also very busy, with nutty drivers popping in and out. So it wasn't a good time to see what it would do speed wise.

I believe that a rough idle and poor shifting of the transmission will wind up being a TPS. I had that problem on a few of my older cars in the past. I will try and see if resetting the ECU will make things better, but I really can't complain about the way it runs now.

I DO notice that the engine doesn't respond as well when the fuel level is under 1/4 tank, so I fill up then.

Thanks