my 1996 626 has a fuel injection problem, seems to work if I keep at least a half of tank of gas or more - any ideas?

 

Not enough info:
What are symptoms (at start, idle, and cruise)?
How many miles on the clock?
Why do you suspect injection?
Describe how you began to notice the problem.
Is the check engine light on?
Have you had an OBD diagnostic run done? If so, what were the codes (ALL THE CODES) shown?