JZS161 V300 Severe Misfire/Bucking - Possible TPS?

[jdmvip]

Hey guys

I thought my Aristo issues were solved but they're just getting started.
I initially noticed the car would stop accelerating as if I took my foot off the gas but it never seemed to misfire and it didn't happen too often.

Things I've done to the car to fix it:
-Replaced fuel pump with Walbro 255
-Fix coil pack connector issue on one coil
-Clean VVTi/OCV Filter
-Clean VVTi/OCV Valve
-Clean MAF

But in the last 5 days the car has become horrible and has gotten worse each day so I've taken Aristo off the road again. It will violently misfire at idle sometimes, especially just before coming to stop. The car will hesitate and misfire violently on take off. The worst part is when trying to accelerate between 1500-2200 RPMs, going up a hill if I'm in that range the car constantly misfires like crazy unless I floor it to get to a higher rev range (even then it's starting to misfire and break up at higher RPMs).

I checked for codes and believe I got a code 39 but I'll post a video to make sure I'm right (I believe code 39 is ABS?).

I noticed that when I get on the throttle I hear a clicking right away from my TPS, this is not normal right? It also rattles sometimes.

I also notice when starting and stopping the car I hear a loud whining/metallic screeching of some sort (almost like squeaky brakes) from the front right of the engine bay (while sitting in the car).

I believe the TPS could be causing some of the issues and hope that's all it is.
The reason I think it could be the TPS is because the ECU depends on correct readings to determine the timing and fueling IIRC.

What do you guys think?

Thanks anyone/everyone for your help.

Cheers

[RyanV]

You've had so many small annoying problems with the car. Can you give us a summary of items that you have replaced or maintenance that has been done?

If you still haven't tackled the valve cover gasket, you could be getting oil leaking into the spark plugs. All the issues may be tied to one thing that has not been changed, so for a better idea on suggestions a complete list of what's been done will help us to offer suggestions

[jdmvip]

Thanks so much RyanV

I honestly can't remember 100% but quickly added a few things to the original post. That's an interesting thought about the valve cover gaskets, I've ordered them along with a new TPS an hour ago. I'm planning to do the gaskets and new spark plugs at the same time.

[RyanV]

Go back to basics if it hasn't been done already....Air and fuel filters and spark plugs. While you are changing the spark plugs check the resistance across the coil packs. I think they should be something like 0.8 or 0.9 ohms.

If that doesn't work then start looking at more complex/expensive items.

[jdmvip]

Thanks Ryan.
The air filter is good, it's almost a new TRD air filter from Japan (there is a small hole in the airbox at the bottom but it was there since I've had the car before the horrible misfiring).

[jdmvip]

My friend noticed there was corrosion on the front cylinder spark plug boot. We sprayed off the plug and boot with carbon cleaner and it got a little better but a day later it still misfires the same.

I'm not sure how but it seems just from sitting that water is getting into the boots, is this from condensation?

He recommends that I change the cover gasket, coil pack connectors and plugs-with dielectric grease (but no point in doing plugs until the gasket is done).

[Megatol]

I checked for codes and believe I got a code 39 but I'll post a video to make sure I'm right (I believe code 39 is ABS?).

Actually error code 39 is VVT-i system issue. If cleaning VVT-i valve didn't help, I would recommend to change it, it is not expensive - about $95 in US (part# 15330-46010)

[jdmvip]

Thanks so much Megatol, so it looks like (hopefully) my issue is now just the VVTi as you suspected even though I only recently got the code.
I have all the parts I need including new VVTi and will try to install it all this weekend.

I'm hoping I can get the Aristo running again.
I owe you a really big thanks Megatol if the VVTi solves it!
Speaking of that where is the info about code 39? Everything I read said code 39 is ABS, we need better info here about the JDM VVTi codes.

[Megatol]

I'm getting info from the Russian forums about 39 code.
Error codes in English http://alflash.com.ua/Diagn/MILcode.pdf

[jdmvip]

Very helpful, Russian websites often come up when I search for parts of JDM information actually.