KE-Jetronic – adjusting and assembling on Audi 80

I have really spent a lot of time trying to adjust that German injection system. I tried to clean it, to set it up somehow, to reset the settings – yet had to warm the engine up for hours and the fuel consumption frustrated me from filling to filling. Finally I collected altogether the information about the KE settings and adjustments and went to my garage for the whole Saturday to deal with it once and for all.

Items you are going to need: a tester, a carburetor cleaner (or a cut-off plate cleaner – the main idea is that the container should be under great pressure), a hexagon screwdriver set and a beam caliper. In case something else is needed I will mention it in the following text directly.

The process:

1. Let’s remove the electro-hydraulic regulator terminal screws as well as the potentiometer terminal screws and detach all the junction pipes from the discharge manifold (caution – the petrol is under great pressure there so beware). When you are done, remove the discharge manifold itself (there are two screws) and you will see something like a separator there (my one was damaged so I ordered a new “049 133 485 A” one and it fitted well).

2. Remove the electro-hydraulic regulator itself (don’t loose the two spacer rings located under it). Apply the carburetor cleaner to each of the two holes. After that you will need to find a screw from the inner side – there is only one screw so you won’t make a mistake. Unscrew it. Under it you will find a deepened hex screw. Use your beam caliper to measure it – should be 6.6 mm. Adjust it and screw it back. Now put it aside – you won’t need it until assembling the whole unit back together.

3. Take the metering unit; unscrew the plunger screw nut (don’t loose the hollow disk). You will see something like a screw hat either on the screw nut or on the plunger itself. It has a screw thread and a hole in the middle (a screw bushing) – unscrew it as well. Remove everything, use the carburetor cleaner to clean all the holes one by one until you are totally satisfied and get a feeling of cleanliness and freshness.

4. Don’t forget that you can also clean the system pressure regulator at the same time. It’s as simple as this: unscrew all the spare parts and apply the carburetor cleaner. Be careful because the rest of the petrol is still under some pressure.

5. There is a roller under the discharge manifold – it should be set to 18.5 mm towards the metering unit level. You can use the 3-mm hex key through the corresponding opening. Afterwards set the default position of the potentiometer pressure disk to 1.9-1.1 mm.

6. On the bottom of the discharge manifold there are four screw caps (in case you have a four-cylinder engine). Under them the fuel delivery adjustment screws are located. A specialist told me that the distance between the metering unit and the screw should be equal to 10.5 mm, my engine won’t start with those settings however. After setting it to 8 mm everything appeared to operate well.

Now that we have managed to clean and wash all the parts, let us assemble them back together.

1. Insert the plunger back (observe the correct side), the hollow disk (the side also matters) and then the screw bushing. Screw it in until it reaches the level of the inner screw and then slightly sink it in until it reaches -0.6 mm in relation to the inner screw itself.

2. Check the screw caps (I didn’t screw them tight enough and got a fuel leak), place the spacer ring under the metering unit, screw the metering unit itself to the corresponding spot as well as the system pressure regulator.

3. Attach the metering unit (don’t forget the separator), the pipes and the system pressure regulator.

4. After you are done you may check the equability of the cut-off plates loading (although that is not obligatory). Take the four cut-off plates out of the inlet manifold (already connected to the discharge manifold) and connect the №30 and №87 contacts together instead of the fuel pump relay itself (as long as I’m not mistaken with the numbers). After that immediately check whether the system is leakproof. This may be followed by a hissing sound because of the fuel going through the pipes in the reverse direction. If everything is fine, then lifting (slightly) the pressure disk will result in the fuel being sprayed.

Insert the cut-off plates into the bottles and check the equability of the dosages during partial opening and during the full one (10-20 seconds would be enough for each check). If you observe a great difference (more than 10%), disassemble the measuring unit and adjust the screws under it. Take it easy, as they are pretty sensitive.

That’s it, to make the long story short.

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