Thanks Matt for the explanation, this is vert. Helpfull.
And Dave I am looking forward to your article.

Greetz...

Hi Matt, Thanks for your reply, I understand the part your talking about. When the earth is removed (by the ignition module) it induces a certain voltage trough the primary coil. What I don't get is the burnline wich is caused by the spark jumping over the sparkplug gap, BUT there aren't any sparkpl...

Hello technicians,

There's a thing I never understood when I comes to the primary ignition waveform. Where does the burnline come from? In secondary it makes sence to me, but in primary the current is just being grounded by the ignition module isn't it?
Or am I thinking in the wrong direction?

Hello Matt, I did the trottle test WOT until the rpm limiter. I have cleaned the Air-Mass meter and the engine runs much better, but I'm still not happy with the second throttle test. As you can see the voltage is a little bit higher, although the lambda signal still shows lean. Shouldn't the lambda...

Hello Nige,

Thanks for your reply, as far as I can tell there are no vacuum leaks. I've checked it all. Tonight I will try to clean the air mass meter and see if there is any difference. You wil find the results in this topic tomorrow.

Willem.

Hello all, I have a problem with my BMW 318 '98. The engine runs very lean and has no performance at all. When I do the snap throttle test the air-mass meter doesn't go above 3,5 Volt. Can I asume the air-mass meter is defective? Here's the waveform with lambda signal in red: acceleratietest.gif (Ex...