This sounds exactly like a pinched lower injector o-ring. Do a fuel pressure test. Test the fuel pressure eat idle and note the pressure reading. Shut the engine off and watch the gauge. If pressure bleeds off then you have an injector o ring leaking. If this is the case, you will have to test each injector. Dont do this by unplugging an injector connector with the engine running, as you can fry the ECU. Use the search and FAQ sections on this site. there are some write-ups that detail ways to track down the leak and fix it without a ton of rework. Hope this helps. Keep us posted.
