96 buick regal 3800 type 2

i have a 96 buick regal 3800 type 2 motor with 150,000miles has been a great car i am getting a p0300 error message replaced coils,control module, spark plugs,wires and have checked for vaccuum leaks repaired anything that looked bad still idles like crap am going to check crank and cam sensors compression any help would greatly appreciated i am pulling out what little hair i have left SEASONS GREETINGS THANKS CHRIS p.s. snap on computer said it was missing on 2,4,6 thank you....p.s. whent through a water puddle before all this happened checked all connections for water none MERRY CHRISTMAS TO ALL:banghead::banghead::banghead:

(http://forum.doityourself.com/newreply.php?do=newreply&p=1275794)

try unplugging one injector at a time on that bank. If the miss lessens, then the unplugged injector is the issue. These injectors are run in series, and one dead shorted one can cause the whole bank to act irratic.

did a compression test one cyl showed 0 compression rocker arms look good going to retest then check valves not enough time in a day ...found the problem it was a broken spring hope this is all going to replace spring tue. THANKS FOR THE IDEAS MERRY CHRISTMAS will post if it is