73 914 1.7. Went to change from 2nd to 3rd, and throttle stuck. Checked and spring in back is ok. When I move the throttle arm, nothing happens. Same in all positions...about 5000 rpm. Suggestions?

If it was a Lexus you could sue!

Check all your vacuum lines and be sure they're attached, check the throttle cable behavior at the throttle body to see if it's moving freely and most importantly returning to the idle/closed position--mine was 'sticky' for a while but some cleanup with WD40 and some lubing got it working smoothly again.

I'm pretty sure there's a manifold pressure sensor as well as a throttle sensor on the stock FI that can go bad and manifest like this too...

The MPS going bad won't give you those kind of symptoms.

The problem is almost certainly the throttle plate itself sticking open. On a 2.0, sometimes the bellcrank can actually get stuck on the top of the manifold in rare cases. I don't think a 1.7 has the same sort of problem, though.

You can eliminate the decel valve and AAR by capping off the ports that they plug into. But if it's sticking at 5K, that is probably not a large enough vacuum leak to cause that.

Have a friend mash the pedal while you look at the throttle body, the throttle valve, and the throttle bellcrank. Also unhook the cable from both ends to see if it sticks on its own. And check the action of the pedal when you have the cable unhooked.

--DD