I just redid my head gasket on the 1.6 NA hydraulic lifter engine. Took the head totally apart and cleaned all the valves, checked the hydro lifters, and inspected seats. Everything checks out and put it back together. I put the 1 notch fiber gasket on there and torqued the head down according to Bentley manual procedure using new German 12mm head bolts. The pistons were at half way so there wouldn't be any valve-piston interference. Then I did the mechanical timing of the valves, pistons, and (Performance Diesel) injector pump. Got the pump set on 0.95mm (about 0.038 in). Turned everything by hand to make sure there was not any interference. I also took apart the injectors, cleaned them, and torqued them back together to spec (70 N m)
When I started the motor up, it was running like it was on 2 cylinders. Actually, the #1 piston intake port was huffing and popping out exhaust, but the engine did run extremely rough. I did a leak-down test on cylinder 1 with a tool that I made from an old injector body. The piston was at TDC and the cam was in the closed position, but I had 100% leak out of the intake manifold...
So I took the head back off to see what had happened. I was expecting to see a broken valve, broken lifter, or something. But there was nothing apparently wrong! Interestingly enough, #2 and #4 cylinder were black from the brief combustion, but #1 and #3 were totally wet with diesel fuel and evidently NEVER GOT ANY FIRE! So #1 and #3 looked exactly the same, however only the intake on #1 was back-firing through the intake port. I'm absolutely stumped.
Is it ok to re-torque down the head with that same head gasket, bolts, and torque procedure or do I really have to buy 10 new bolts and a new head gasket and just hope for the best?