Could also be water in the fuel.
Check the sump portion of the fuel filters for evidence of free water
..... then be sure to wet the filter cartridge O-rings/seals with fuel
when you reseal them - a possible source of bubbles in Larry's posting.

Flat seals on filter cartridge housings are notorious 'leakers' and
must be installed 'wetted' with fuel oil so that you insure that they
seal.


In article .com,
" wrote:

Thanks Larry. I've looked really hard for air leaks and fuel leaks...
The fuel tank is higher than the engine and I have bled the thing very
well. I'll look some more, but don't understand why it would get
better when it gets warm... Also, if the engine has been wamed up
sometimes it doesn't have the problem the next day... If it was the
injection pump would it ever run well?

-- Tom.