cuda6pak

Yes, always used premium fuel, doesn't matter what station I get it at. Someone on CL had mentioned that it could be my VSV for fuel pressure. Does that sound like the case to anyone?

my car has EXACTLY the same symptom. Did you fix the problem with confirmed root cause? Update: Swapped out ECU's with a known good one. Still did not fix it. Seems like the only things left are the fuel injectors....on top of my continuing A/C problems, I'm getting closer and closer to selling this thing.

When I bought my LS400 about 2 months ago, the car had already been converted to R134a. The compressor was making a very slight grinding noise like the bearing was starting to wear out. The A/C always worked great on the highway at 45+mph, but around town it was just somewhat cool. I figured it was just low on refrigerant. Fast forward to this weekend and I make a trip down to Florida. The A/C worked the entire way down, nice and cold. I even noticed in Florida traffic when I finally got there that the a/c was staying very cold and working really good. Well I park it over the weekend, then pick it up at the valet 2 days later to head home. I drive off for a few minutes and then put the A/C since I was on the highway and it would be nice and cool. No A/C! The compressor wasn't even turning on. Got home last night and ran the A/C diagnostic codes as per lexls.com. Nothing shows up, just a 00 (indicating system should be fine?). The A/C button stays lit up after I press it and does not blink. After reading a few threads on here I decide to test if the compressor will even turn on. I got underneath the fuse box and pulled the MG Clutch relay and bridged the two copper terminals with a wire. The compressor immediately turns on, so it should just be low on refrigerant right? I put a gauge up to the low side of the A/C system and the pressure is at about 15psi. Great, hooked a can of R134a up to it and got the pressure up to a nice 35psi. Checked the A/C......its still blowing warm! I can hear the compressor turn on everytime I turn on the A/C, but no cold air whatsoever, even at highway speeds. Does anyone have any ideas what could be wrong? 95 degrees and no A/C sucks!

Is there a schrader valve hook up somewhere on the fuel rails to hook a gauge up to? I glanced after work today but didn't see anything.

Spark when it wont start? It's hard to say that, because you would think that if it was spark related it would do it all the time. There is a window from about 2 minutes after the car is shutdown that lasts for a few hours that it's hard to start. If it's cold, starts right up. If it has just been shut down, it will start right back. Which makes me think what eatingupblacktop suggested is that there are some leaky injectors. Whatever it is, it doesn't sound like a normal LS problem as I can't seem to find anyone else with this same issue.

Just to update the thread I bought a new coolant temp sensor from Autozone and installed it. Still acts exactly the way it did prior to install, hard to start when warm and still smells a bit rich at idle. Haven't driven it enough on this tank to check on fuel mileage but I assume its the same.

Good tip, hadn't thought of that! The only thing I can say is that there is no SES light on and that the car tends to smell at idle. It runs completely perfect otherwise with no hesitation anywhere at any throttle position. Also I noticed that if I shut it down when warm and start it right back up in about 15 seconds, it starts up fine, but if I let it sit for more than a few minutes it does what I first posted.

I posted about this problem on clublexus with no help so far, wanted to see what you guys thought. When the car is cold, it will start right up first crank no problem. But if it has been driven for anything more than 5 minutes, it ALWAYS takes two cranks to start up. And by that I mean the first time I hold the key over to crank it, I can hold it there as long as I want continually cranking and it will never catch or even act like its starting. But as soon as I quit cranking it, wait a second, then start cranking again, it will start right up! So far the spark plugs, wires, rotor buttons, both ignitioncoils, fuel pump, and timing belt have all been replaced. Not sure what's left?