OK, you asked for it...

K-jet is self explantory.

Since I am the son of an electrical engineer, I used the "L", for loopstick, to remember the series of solenoid type injector systems. It's not quite what Bosch called it.

The first type, called L-Jetronic, was seen mostly on Volkswagen and Japanese cars (Nissan 240/260/280Z, Toyota Cressida/Camry). It uses a flap type air flow sensor (anyone here remember prying the black cover off and readjusting the big clockspring?). The "L" stands for Luftstrommesser, literally translated to Airflow meter. I don't believe Volvo ever used this system - but others will pipe up if I'm wrong. The airflow meter was mechanical, had an analogue output, and there was no detection of barometric pressure (altitude compensation).

Using an old principal that states, by measuring the amount of current it takes to keep an electrically heated wire maintained at a specific temperature, you can measure the amount of heat removed (in calories or BTU) and therefore determine the quantity of air molecules that passed over the wire. The number of oxygen molecules in a cubic foot/metre of air varies by temperature, weather, and altitude, but is the absolute basis for determining the correct amount of fuel required for the correct mixture. The hot-wire system could more accurately measure the air MASS and made for better emissions control. The formal name for this system is Luftmassenmesser Hitzdraht, which dissected in my mediocre German, means Luft (air) massen (mass) Messer (meter) Hitz (hot) draht (knife).

Had enough??