Back in 1969, Alfa Romeo started putting a diesel mechanical fuel injection system in their US spec cars. The system is called SPICA and has four small pistons which pump fuel into each cylinder (in front of the intake valve). The control end of the SPICA system is an analog computer that takes inputs from a number of sensors along with throttle position, then determines the amount of fuel that should be pumped into each cylinder. The SPICA pump is driven by a cogged belt that runs off the crankshaft. The SPICA system had four individual throttle plates (one per cylinder), until 1980 when they went to a single throttle body system.

Alfa Romeo used SPICA mechanical fuel injection until 1982, when it went to a Bosch L Jetronic EFI system with a computer for the fuel injection system and one for the ignition (spark). It cleaned up the emissions of the mechanical system, but the car lost a lot of the mechanical feel.

In 1990, Alfa Romeo went to the Bosch Motronic EFI system. The Motronic cars feel more like a Toyota. They're easy to start, need less maintenance, idle smoother and have more power and less emissions. However, they feel less special and the motor feels much more Toyotaish. The feel of the early Alfa Romeos was greatly diminished.

Interesting for owner of a Skoda diesel that worked fine until a recall to reverse the emissions fiddle. Since then half the injectors rapidly burned out, and cannot be refurbed.

Could be the amount of fuel is too high for the original injectors, so they burn out. The electronic control (I believe it's a coil) may be held open too long and thus overheat.

I once drove a VW Toureg diesel (notorious for the VW diesel cheat) from Lompoc to Castaic (around 130 miles) on an 1/8 tank of diesel. A Toureg is a heavy SUV (nearly 2 1/2 tons). The EPA figures are 28 mpg. The fuel tank is 26.4 gallons, so that puts the fuel economy at close to 40 mpg. The fuel injectors were working about 40% less at highway speed, so they would last a lot longer and stay a lot cooler.