Straight to it, about 4 or so weeks ago I pulled the upper plenum to fix a fuel weeping issue with the return line or so I thought. The smell was faint, wasn't there all the time, the car ran fine, but any fuel smell under the hood to me is no good. Plenum is off, ive checked the a/n fittings on the return and there good, then I notice that the fuel rails have a ring of light dust on them around every injector, I had a bit of a smell round the rails and I could smell fuel faint but there. Since I put the injectors in the rails, I figured id possibly pinched the orings. injectors are out of the rails, 6 pinched top orings. Later I had efi hardware (a local specialist) take a look at the rails and fit new orings. There comment was that the chamfer for the top oring was shallow and the fitting difficult, but all good now. The engine is back together a few days later, the car hasn't been started for a couple of months, I turn the key and it fires up,but runs at 2000 rpm, I replaced the iacv with new, but I also hearing a loud knocking from the engine. I've heard the same sound a couple of times before, but years ago, so I let the engine warm up and plugin data scan, timing is solid @15d, iacv is doing its job, oil pressure is about 10psi at 800rpm and increases with revs, everything looked good. I’ll say when it happened the first time the sound went away quite quickly, I’d put it down to lifters and cold outside temepture, and hopped I was right. This time it’s not going away though, I give the engine a small rev and the noise increases in sound and is in rhythm with engine revolution, what! The sound I thought, was coming from the top of the engine drivers side exhaust camshaft, that area anyway, which made me think a lifter-lifters hadn’t pumped up at all, and were now being hammered by the cams. The engine is apart now the driver’s side exhaust cam cover is of, I’m pushing on the tops of the lifters one at a time, every lifter is spongy, they all depress down about 10mm, seems the only thing holding them up is the internal spring. But I’m not convinced the lifters are the source of the knocking hammering shit that’s going on. To my untrained ear it sounds more like rod knock, the last thing you’d want. I ‘ve looked at a couple of ways to check for rod nock, and used the piston at tdc rotate a little until the piston being tested starts is downward movement, this they say will gap the offending rod bearing at the top, if a gap exists, and by pushing down with a blunt rod through the spark hole you’ll feel movement downward. So, I did it and no movement exists downward at all. The oil was dumped, there is no metals in the oil or oil filter..F/a. Atm I’m thinking of pulling the camshafts and rebuilding the lifters again, joe imbesi who built the motor rebuilt them at the time, he said they were good. Short of pulling the engine and checking the bottom end bearings, I’m stumped. Anyone here have anything similar happen? Ideas please.