Kangoo 1.5DCI 2007 EM light, stop light around 2-3000 revs

Hi All, My Kango is doing my head in. Initially found No3 injector off, bought a new one, started first time but needed coding. Got it coded, it broke down! Got it home, managed to start it, leak off test showed No4 injector down. Got it recon'd. Put it in, started 1st time. But I knew it still wasnt right as you could hear that deisel inj "tick". Ran the van and found the EM light and STOP light flashing at around 2500,3000 revs and it would momentarily cut out, take your foot off the accelerator and it would run again. This is just under load. If you manually pump deisel and start the van it ticks over perfectly. Hold the revs at 3000, perfect. Let it tick over again and its lumpy and the occasional misfire (deisel tick) is heard. Checked all threads and it looks like the same problem is repeated on here but no one has fixed the problem.

Any ideas guys? Can I check the fuel pressure regulator in any way? Oh, and on tick over, a bunch of tiny air bubbles come through the pipes very few seconds, is that normal? Its not just 1 or 2 bubbles, its like foam bubbles.

Help!:crazy:

Any advice would really be appreciated.