First off, I searched for the past 2 hours and have not been satisfied with any of the posts.

Today, was the first time I started noticing the rough idle thing that seems to be the problem with the GS400's. I am getting the exact same symptom. AC on, no rough idle. In the morning before it completely warmed up everything was fine. When I got off the highway and stopped at the light, i noticed the roughness kick in.

So right away, i drop by the strauss and pick up some TB cleaner and a toothbrush. At work there are a bunch of tools so I took them and removed the TB pipe sprayed the cleaner, and toothbrushed it. Damn that was a hard job especially since you cannot open the TB externally, and that thing was hot from the drive. Reasembled everything, and the problem is still there.

My question: wasn't this supposed to be a problem for the gs400 people? Or can this be related to my car having 84k miles and nearing the 90k service?

None of the other posts have ever found a legitimate solution to this. So can someone suggest something. Thanks in advance.

 

umm i don't recall hearing this for the gs430 indeed. that's funny. i especially tried it on my sc430 with ac off and it's silky smooth.

maybe other gs430 members can chime in

 

Yea this is just pissing me off. I hope I am not the only one.

 

I had this problem, but installing a grounding kit and SRT intake has made it go away. I'd definitely do a grounding kit if you haven't already.

 

****, you know i was thinking about doing this. I have a whole bunch of Rockford Fosgate 2 and 4 guage wire, and 2 Stinger 5 way splitters. Does anyone know of hand the major locations that the wires should be connected to?

 

Even though you have the wire, I would not do this yourself. The connections should be soldered (4Ga wire to end terminals), it is difficult to solder 4 ga, it wicks heat away too quickly.
Check out www.teckkits.com - Paul Kwan.
His kits are excellent for about 75-80 bucks. Wasn't worth the time and effort for me to cut and solder etc.

 

Wow, those look pretty good. Ok i guess i have a first mod comming. Ground kit.
Thanks.

Anyone else have any more suggestions on improving this roughness.

 

Try these:
https://www.clublexus.com/forums/performance/96028-pleasantly-surprised-plp-sfi-and-grounding-kit.html

https://www.clublexus.com/forums/sho...t=ground+point

https://www.clublexus.com/forums/sho...ounding+points

 

Thanks, I actually read all of those posts already. If you search for rough idle, or low idle you will get these as well. Thanks, again, and keep it comming.

 

ok update. So i just ordered the grounding kit. I got the black one with siver terminals. Will see what it does for the car.

Soo, nobody thinks this is a nearly 90k issue that I am having?

Oh, and I am doing Engine Oil, Trans Oil, Oil Filter, Denso spark plugs, and hopefully the grounding kit this weekend. I already did the K&N drop in two weeks ago.

 

When you talk about idel does it mean your RPM jumps around a bit? Because my car the rpm stays solid but you can feel the car bump like the engine is moving at idel? Do I have the same issue I thought it may be because of my Intake & Exhust?

 

No, i mean that the idle goes too low, and I get a vibration. It is a very common problem with the GS400. You can search for "low idle" and get a ton of info about the gs4s, and how most of them just tighten the throttle cable. I cannot even do that, since the 430 don't have a cable at all.

 

when there is idling problem, the rpm is usually very low like 600 or even 500rpm

 

Ok, today i found out that my car has the same exact problem like the 400s. It turns out the AC on, and light on fixes the problem. But that is only because it raises the RPM. So still taking suggestions.

 

you have to turn BOTH the ac AND the light on? if so then it's weird. as long as my ac is on that's good, i don't need to turn on the lights?