LC200 Engine Stumble / VSC-4Low warning etc (1 Viewer)

[Tundra61]

Hey fellow LC lovers !

I have a 2008 LC and the engine occasionally stumbles/shudders when running up hill at high way speed and all the dash warning lights come on. If I stop and restart the car the stumbling/shuddering goes away but all the warning lights are on. This has happened before. Last time I took it to the dealer and they said the ignition coil in bank #2 was bad so it was replaced. I also put in new plugs. It did't do it for a while but the problem came back today.

Any ideas on what it could be? It only seems to do it when riding uphill under acceloration. IN all other situations it drives as expected. Hard acceleration on flat ground is no problem. It's only when accelerating at highway speed going uphill. As a preventative measure, I also installed new coils in the remaining 7 banks.

Also, can anybody suggest a good scan tool? I want to be able to check error codes myself when this happens.

Thanks all - mike

 

[TeCKis300]

So the interpretation I'm understanding is that this only occurs under high load, high speed running.

I'd definitely get a scan tool before proceeding further to understand what the ECU thinks is going on. Any generic OBD-II reading on amazon will work. Can be had under $20.

If I'd had to guess:

I'd typically attack the plugs and coil packs too, but looks like you have that covered. If you've had extended prior issues with those, it's very possibly that the cylinders affected have carbon and crud buildup. This would cause knock/detonation/pre-ignition in those cylinders under these conditions. I'd potentially look into some injector and cylinder cleaner/treatment. Like seafoam. Dealers have more sophisticated machines to do more thorough cleaning.

Are you getting flashing lights, like a flashing check engine light, under these conditions? That would indicate knock.

If I had to guess further, O2 sensors, fuel pump, clogged cat. Though can be many things. The codes will help isolate the issue.

 

[Sandroad]

Here's a scan tool with some good features. For sure get a tool, it will save you from things like feeling you have to replace all coil packs when only one is bad!


Amazon.com: Innova 3030g Diagnostic Code Reader / Scan Tool with ABS for OBD2 Vehicles: Automotive

It's odd the problem only happens when going up hill. I wonder if that means it's a fuel supply issue. Anyway, use a scan tool and see what's up.

 

[DeckerT4R]

How many miles are on the truck?

Misfires can be caused by many different things. Since they replaced the coils and plugs I'm assuming that's the codes it was throwing.

 

[Tundra61]

Truck has 78k