wadamsiv

2003 LS 430: I changed all the coils and spark plugs. Tried different coils and new spark plug on one cylinder still not firing, but no spark. Wondering if it might be the wiring harness to that coil? Wondering if it might be the computer (hope not)? Any suggestions appreciated.

2KHarrier

Try to refrain from starting multiple threads with the same question. This clutters up an already cluttered forum.

Be patient and you will get responses on your first posted thread.

A quick search yielded many results regarding coils and the VSC light.

Here's one thread which may help;

https://www.clublexus.com/forums/ls-...e-shaking.html

Oh, and welcome to the forum!

Stu

Do what I did when I had the same code. Take the car to a mechanic and have him plug it into an OBD reader and read the code(s) This will give you an idea of where to start. Randomly replacing parts will be quite expensive and relies on luck to fix the problem.

Arcturus

Instead of replacing parts, try swapping parts and see if the problem moves to another cylinder. When it does you know that is the problem. Hopefully you know which cylinder this is. If not get a scan tool to find out which one it is.

It could indeed be the wiring - you could start by inspecting the wires for cuts or tears. Then using a multimeter / ohmeter to measure the resistance across each wire and see if you see one that is different from the others.

I had a problem a long time ago where one of the spark plugs wires was burned by an aftermarket header and grounding out on it creating a miss. There is high voltage in the wires and any gaps in insulation will allow the spark to leak out.

LS430inDE.

2KHarrier pointed you to the spark plug thread that I was the OP. He's giving you some good advice IMO. Read my thread and you'll see where I accidentally pulled the white conductor out of the Coil On Plug (COP) connector. The picture can be seen on POST #21 of the thread. I'd also suggest you get a OBD2 scanner. It would give you the diagnostic/trouble code and could literally tell you WHICH CYLINDER has the fault/misfire/no spark condition, etc!

Let us know what you find!

Gronemus

Guys,

He already solved his problem according to the other thread he started on the same topic...