I was just given a 1990 560 SEL with a misfire. I narrowed the problem down the fuel distributor, I think. The outlet on the fuel distributor that leads to the passenger side third cylinder from the front, is not pumping out fuel, like the rest of the ports. Any ideas? Thanks
Does this have the Bosch CIS? If so note that the "C" stands for continous. This means that fuel is going through the fuel injector all the time not just during the intake stroke.
Assuming that you determined the problem by disconnecting the pipe at the injector and saw no fuel flow, I'd disconnect the pipe at the fuel distrutor and check for flow. If so, there is blockage in the pipe. If still no flow the blockage is in the distrubtor. I have seen rust blocking passages in these systems.
If you pulled the injector to check for flow, the injector may be bad. Check for flow through the pipe before replacing the injector
I think I wasn't clear enough before. I disconnected the pipe from the fuel distributor and no fuel is coming out of the fuel distributor. (Only that one port. The other 7 are find)
Is is a big deal to take the fuel distributor apart to clean it? It looks simple from the outside.
Thanks!
Alford
Even I didn't try to take apart the CIS distributor... it is supposedly complicated but the real thing that fail in these distributors is the neoprene seals.
If you could find an authorized Bosch fuel repair center... see how much it is to rebuild them. Forget about buying used units now... as it is so old.
They are really not that complicated. Like anything else you have to pay attention to things when it is disassembled. Make sure that you do not tear the seals when opening it up. I would think that that there would be seal kits available but I have not been able to find any.
The rebuild kits are available, but only to authorized bosch remanufactures.
These fuel distributors new are worth more than the car is these days, hence why when one is known to be faulty the car gets scrapped most of the time. There is no reason why one couldn't find a good used distributor, I've had much success doing so and they appear on eBay regularly (just make sure its the correct version) - They seem to last well if the donor vehicle was well maintained with regular fuel filter changes. It seems that rust scale and crud from the tank getting into them destroys them.
late w126's have KE-jet, early, pre update w126's use K-jet. the distributors are not interchangeable.
That is unfortunate that the kits are not available to regular people. The fuel distrubitors are not very complicated. The carburetor in my 1982 Cutlass was much more complicated. There are precision surfaces that must be protected.
The only place that there could be problems is if the adjustment screws (they look like set screws) go out of adjustment during cleaning. Next time I'll apply peneratrating grade Loctite to the screw with a fine grade hypodermic needle to hold it in place. A spring of the correct size between the adjustment screw and the sealing-cap screw should hold it in place too.
You are corret in saying that rust and crud causes problems. Really this is the only thing that can go wrong. unless the seal that acts as a diaphragm fails. If the diaphragm is ok, there is no reason that the rebuild cannot be sucessfull.. There are several screens in the distributor. The disk shaped ones can be pried out with out damage. The cylinder shaped ones can be removed with a properly sized sheet metal screw but there is some risk of damage.
The first one that I worked on I just used brake cleaner and compressed air to clean the passages. The problem with it is there was rust blocking the fuel-return-to-tank circuit. This prevented the pressure regulator of the K-Jetronic from working right.
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