the vct system dosnt start to function until 4000 rpm or the second start up.i found that a prior shop had installed 2 left hand hyd. tensioners and both seals on them where cut.and i also had 1 that had collapsed completely.i ended up pulling all followers off and installed new tensioners.i spun the engine over to prime the system and they have heald in place and havnt jumped time.im in the proses of working on a few other vehicles and havnt had time to reinstll the fallowers and valve covers to see if it lives.ill let you know.