I discovered a problem with my door locks (both sides). Last year, I transferred the lock cores to the new repro handles. That required a bit of machining of the holes for the cylinders in the new handles, but in the end, the keys worked fine in both L and R handles.

But when I got done with my build, I found that the keys barely worked. I could lock the doors with the key with some effort. But I could only barely use the key to unlock the doors, with lots of effort and jiggling.

Here's some excess details. View of the right door inside, lock open.

Turn the key to lock the door.

Door is locked.

But the locking lever inside has barely moved.

And the key will not rotate to unlock the door.

Until I pushed the interior lever to "lock".

Then the key rotates to "unlock".

The interior lever also moves to "unlock".

And the door opens.

On the other side, I have the door card and plastic sheet off. I hit the lock mechanism and linkage with a healthy dose of spray grease.

That seemed to help. When I lock the door with the key, the interior lever moves to "lock". And then I can unlock the door with the key.

Anyone ever see this before? Any reason the door card would interfere with the lock linkage rod? (It does not seem to make contact.)

My 914 door locks work very smooth and easy. Couple things I did to ensure they functioned like this:

Ensure your key pulls the wafers in 100%, even a tiny bit of wafer sticking up can make the key not want to rotate.
Really clean and lube the inner door mechanism. I removed mine, really cleaned until everything moved freely, nice solid clicks and snaps into place.
Pay attention to inner door handle adjustment. There isn't much, you can scoot the inner handle a little forward and back to get the lock position correct.

It takes fiddling, but will say my current 914 has the smoothest locks I've ever known on any 914 I've owned. Totally worth the time.

When I turn my key outside, the inner lock will sit flush with the handle.

Thanks.

Any other suggestions out there?

Second the inner door mechanism. The pieces need to slide past each other. Dirt and old grease can gum it up. Your car looks really clean though!

I think your linkage is dragging. Is it in a bind with the door card? I ask because in the first pic that black plastic escutcheon appears to protrude away from the card. I've never needed to lube that linkage either. If it drags in the rubber holders I'd check the linkage to be sure it isn't rough on the exterior.

Are you using a longer screw to retain the inner release surround? If the pass side works, the screw on that side is the correct length.

If you have cleaned the latching mechanisms in the door THOROUGHLY and lubricated them so the "C" piece slides up and down easily, it is the repro door latch that is not working properly. They are really really bad

Check this, see how it works without the trim piece installed. If you have the wrong screw in there it will bind.

Turning into a good resource thread!

Remembering now one of my inner handles was pretty worn out. The holes the rod went into were oval, not round. Just enough the throw from the key wouldn't seat the inner lock all the way.

There isn't much tolerance for worn out parts if you want the whole system to work smoothly.

You put the wrong screw in the interior latch cup. It's only about 4mm long. It's easy to get the cup screw and the window crank screw mixed up when reinstalling them. The longer screw interferes with the lock

The longer handle retaining screw switch happens only once.