There are 2 types of FI systems for the B20 cars -- d-jet and k-jet

The newest of these systems is almost 36 years old at this point. These things were probably designed to have a service life of about 15 years, and overengineered so the lucky ones are probably only now approaching the end of their service life. It wouldn't be reasonable to expect any of the original components to last another 10 years without replacement/refurbishment. If you want it to be reliable, you'll want to rebuild all the mechanical system (fuel injectors, fuel pump and MAP sensors and metering flaps (k-jet), and you'll want to double-check all the electrical components, wires, and connections. The connections get corroded and the insulation on the wires tends to get brittle.


D-Jet is an all electronic system that works by detecting manifold pressure. It was designed in a day where transistors cost hundreds of dollars each. As such it has all sorts of weird analog and mechanical thingies on it. It's an open loop system that just simply does what it does based on a very few inputs (vacuum and if the throttle was depressed recently and the temperature of the engine, and points in the distributor to decide which 2 injectors to fire) and it doesn't check the resulting exhaust to see if everything is behaving as it should. The good news is that it is very efficient and very reliable when everything is in tune and operating properly. The bad news is that the system was designed for a particular cam and displacement and if you change things too much, it simply won't deliver fuel correctly.


K-Jet was used in 1974 and is basically a big mechanical fuel metering thingy. Air moves past a flap, and the faster the air moves, the further the flap moves, and the more fuel gets delivered. All fuel injectors receive the same amount of fuel at the same time. It's a beautiful, elegant, and simple design that was in service in lots of european cars until the mid 80s at least. It is reliable and works extremely well as long as the fuel metering flap works properly.



If you want to set and forget, carbs are easy. Low fuel pressures are a lot less scary if things go bad, and you can tinker with them.

My money, though, is to get a d-jet car and convert it to megasquirt. The system is already very nearly modern in design and retrofitting MS just requires replacing the old, worn out systems that would need to be replaced anyhow.

chris