Not to imply that you don't know how to start it, but, the owners manual does say you need to apply partial throttle ( more when cold). My '89 Jetta sometimes requires pulling the cold start handle when starting hot. This will advance the injection timing when pulled out fully. I'm assuming that this is being accomplished by applying half or more throttle per the owners manual.

That's my two cents worth. Tell me if I'm full of it.

Rich