I have 3 of these forklifts (identical).

One had problems with the crankshaft sensor and showed an error code but started and run fine,
I changed the crankshaft and the camshaft sensors and also changed the spark plugs, and made a tune up. When I try to start it, error 23
shows up and won't start. it fires up and shuts down. I got it started with carburator fluid and started up fine and without error codes, the
next morning, same thing, it fires up but doesn't start.
I start looking for problems, check harness wires and connections... everything is fine.
Until I switch the throttle body, the fuel pump and the oxygen sensor, etc.. with the other forklift's (the one that worked perfectly fine)
and now none of them work now - and both show error code 23 -. The first forklift still won't start and the second one starts but idle wont go up.
I switch the parts back, and the forklift that was working before, works fine but now shows error code 23 too and the First forklift still won't
start up.

Is it possible that both throttle bodies are damage but behave differently on each forklift?

The LPG converters are both new.

I don't understand why is not starting up.

This is my first post here but i always get useful information from this forum and that's why I decided to post my question here.

Thanks.