Thermador XL burner starts at 7:00 position

The left front burner on my stove sparks at the Hi position (around 9:00), but the gas does not flow until the knob is turned to around 7:00. I thought it was a valve problem, and so replaced the valve. I also replaced the ignitors as they were having problems, and replaced several other parts which were frozen. After putting everything back together, things worked like a charm!

Unfortunately, I smelled gas and realized that I had not put the gasket back on the valve before installing it. Took everything apart, replaced gasket put it all back together.

Now the problem is back. Sparks where it is supposed to, but the gas does not come on until the knob is at 7:00. Is this really a potentiometer problem? Does it sound like a solenoid problem?

I previously replaced the potentiometers with the new kit. Is it possible to not buy the whole kit if this is the problem?

Thanks.

Kevin