Bosch Design III fuel injectors

I’ve been researching some updated injectors for the venerable M30 in my E24. Time has marched on since the early style injectors were designed; Bosch and Denso have both produced improved multi-nozzle designs to provide better fuel atomization. These newer “Design III” or “disk-type” injectors can easily be retrofitted to earlier cars.

Given that I’d upgraded the system to Motronic 1.3, high-impedance injectors are required. We also need the older-style “EV1” wiring plug and the older-style retaining clip grooves on the top of the injector to suit our fuel rail. The most common upgrade is the Ford V8 injectors as fitted to umpteen million F-series pickups and E-series vans. However, these are all the older-style metal case design AFAIK. Since I’m a special snowflake, I wanted the plastic cased ones. Just due to my aesthetics viewpoint, no other reason. Happily, there is a very common donor car for these injectors. Most Volvo I5 non-turbos built around 2000 used a 200cc injector that is a perfect candidate.  Happily, the I5 fuel rail is a cinch to remove. Look for the yellow-bodied injectors, Bosch part number 0 280 155 746.

On to some pics! Here’s a direct side-by-side comparison of the two injector styles:

Note that the newer injector is slightly shorter overall, but it’s still a direct fit. The plug is in the same location, the rail clip grooves are there, and the o-rings are the same distance apart. The o-rings are even the same size! The only difference I’ve seen is that the filter looked a bit different (although the same size) and the retaining ring on the front is a disk instead of a cup.

And, here they are installed on the motor: