Ongoing VSV, or something else?

[Mile_High_Flyer]

I have replaced all the hoses on the VSV (VACUUM SWITCHING VALVE) for EVAP etc, but of course, not the other parts. The VSV appears to be fine, the resistances are within spec, the valve opens and closes properly after cleaning, I can blow through it when open, but not when closed, I tried blowing through the tube off the canister line, unsuccessfully, instead of using smoke. After I left the shop where I bought the above hoses, without having done anything, it came right, all was beautiful! I did the hoses after I got home, and it was still good. However, yesterday, it all started turning to custard again. Today was worse. All the usual, bad idle, smell, reduced fuel economy, not-so-smooth gear changes etc. I'm at a bit of a loss as to what to do next! I haven't refueled, as the tank is about 3/4 full. When I did fill up the other day, I stopped as soon as the nozzle clicked off the first time. Wondering whether another reboot by disconnecting the battery for half an hour, might help make things right again once the computer gets itself sorted, after some mileage, hopefully not just temporarily. Or should I drive it some more first, and see what happens?

After that, it got worse. A lot worse! I then removed the PCV valve. It rattled, as it should, but I still cleaned it with throttle body cleaner. I couldn't blow through it one way, but could the other way, and the rattle was slightly louder, and appeared to be more free. I then reinstalled it. Its hose appeared to be fine. I then looked at the 2 Pressure pulsation dampers. Couldn't see any signs of fuel leakage. I then went for a very short run, but it didn't improve. When I got back, I turned off the engine and looked at the dampers again. The screws had risen up. So presumably they are working, with no diaphragm leakage as there was obviously still pressure there. So, I rebooted by disconnecting the battery for half an hour again. It then came pretty well right and kept improving slowly, as has always happened previously, but then, after a time, it went bad again. I then blew through the line back towards the canister, then sucked it, and the line was free. I assume that's how it is supposed to be. We have also checked the VVT solenoids, and they appear to be working correctly. Another reboot! This time it hasn't had enough time to go wrong yet, but I expect it to probably do so soon! I'm wondering if it could possibly be the ECU computer?

When it's starting to go wrong, the first indication usually seems to be the rougher gear changes, then the fuel consumption starts going up, and after a while, the exhaust pipes start to go black. There are no CEL dash lights, and my tester doesn't show any codes.

A couple of days later:
Here we go again! It's started having slightly less smooth gear changes, and the exhaust pipes are starting to blacken! It never seems to lose power, even when it's pretty bad. it can accelerate hard, right up to gear change revs. I'm in two minds as to whether I should reboot again now, or continue driving and see what happens. One time it got really bad, it was so rich it was smoking and even missing. Another time, it came right by itself, until it went out again! It always comes right, albeit temporarily after a reboot, usually for about 2 or 3 hundred kilometres.  I did reboot again, and it lasted about 300km before starting to go bad again.

As a reminder, it's an '04/'05 LS430.

Any more suggestions? Please!!

[Mile_High_Flyer]

As a reminder, it's an '04/'05 LS430 right hand drive imported from Singapore to New Zealand. Everything in English, not Japanese. Done about 230 Km.

 

I have been trying to post the same message on the US site, BUT keep getting told: 

CleanTalk. Spam protection Forbidden. Private list deny. Message seems to be spam. **

Any thoughts on that?

[Lexus Owners Club]

Try again now....you should be able to post in the US forums

[Mile_High_Flyer]

Yay!  Thank you ever so much 🙂

[Mile_High_Flyer]

Since the above, I had to reboot a number of times. The last few, before reboots, I did the following distances. 400km, 300km, 56km, now I'm 2500km since last reboot and she's behaving beautifully. I didn't do anything else, so I have no idea what changed. Great mileage, clean exhaust pipes, beautifully smooth gear changes.  I was about to have the ECU computer checked over by an expert here in New Zealand, but it was holidays so it couldn't be done at the time, but that's when it came right!

I wait in trepidation to see what happens!