I wound up pulling apart the fuel distributor on the '79 242 I posted about earlier with the no start condition. I know you're not supposed to open them but upon disassembly my suspicion was confirmed that I had nothing to lose. Inside I found quite a pile of rusty sediment and other various crud, though no real damage and it cleaned up fine without too much effort.
Now the question is do I attempt to reassemble it and put it back on the car or should I just grab another one from the wrecker? Has anyone successfully put one of these back together or is it like a hard drive in a computer and just so ridiculously precise that I have no hope?
I've done it before and what do you have to lose? Put it back together and see what happens, OK? It really doesn't take too long to reassemble the unit if you have kept everything in order. If it doesn't work, then I'd get a rebuilt unit because if you get a used component, you just might have the same problem with all of the sediment and buildup.
The first Volvo fuel injection was electronic with an analogue computer. It was called by bosch D-Jetronic, D for Druck, German for pressure. It measured intake manifold pressure, and used that information along with engine speed information to calculate injection time.
Next there was K-Jetronic. This was non-electronic, K for Kontinuerlich, German for continuous. The injectors were always injecting fuel when the engine was running (even when the intake valve was closed), flow through them was varied by the fuel distributor, the signal from a plate moving in a venturi was transferred to the fuel distributor by a lever. There was a variation of this KE-Jetronic that was never used by Volvo, which basically added electronic control of the control pressure, and thus the mixture.
Also not used by Volvo was L-Jetronic. This was electronic, L was for Luft, German for air. Air volume was measured by a spring loaded door in the intake flow. Note K-,KE- and L-Jetronic measure air volume, not mass.
A variation of L was LH-Jetronic, the H for Heiss, German for hot. This used a heated wire in the intake flow to measure air mass, not volume. The computer calculated air flow by its cooling effect on the hot wire.
Then came various forms of Motronic, which combined fuel and ignition systems into one computer box.
MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.