Ahhhh, I think I understand now... the only thing throwing me off the intermittent part. Basically, the VE30DE actually has hydraulic lash adjusters instead of lifters. The cams are above the rocker, which pivots on the lash adjuster to push down on the valve. Unlike the lifters, the lash adjusters aren't able to bleed out air while the engine is running. If there is air in the adjusters you actually need to pull them out and manually bleed the air out.
Check out EM-75 for that procedure: http://www.nicoclub.com/FSM/maxima/1994/em.pdf
Its pretty straight forward, I've actually had to do this with the VH45 adjusters (they actually appear to be almost the same design). Anyway, you simply submerge the HLA in oil then take a small rod (I used a very small allen wrench) and you push down on the ball bearing inside it to bleed the air out. As you're doing this you should see bubbles come out. Once its fully bled you can push on the HLA and it shouldn't compress at all.
If your HLA's are mushy when you press on them that procedure should definitely fix it. Good luck!