Zen of...

A guy on FB thought he had reset his VW bus engine valves, but then it wouldn't start. This is a fine lesson in the Zen of VW bus maintenance: 

You have at least one and perhaps two valves that are not closing. If all you touched was the LH valve train, then the distributor is still able to show you when the engine is firing on cylinder numbers three and four (The LH ones. Three is top left or forward left, as seen from the back of the engine. Four is bottom or rear left.) Pop the cap, rotate the engine on the crank bolt until the rotor arm is pointing at the place where number four HT lead used to be, check against the timing marks on the fan to be sure you're at TDC, then reset the valve lash (clearance) to 10 thousandths of an inch. Remember: Firing order is 1342 and the crank rotates two full turns for each full four cycles for a four cylinder engine: The timing marks, therefore, show TDC for one and four cylinders, but don't tell you which cylinder. It could be one or four. The rotor cap is what tells you which cylinder is at TDC, assuming the distributor hasn't been messed with. Rinse and repeat for number four. (Ten thousandths is the "old" setting for before we allegedly got better precision in engine parts and so on. The new is 6 thou, but in your situation you need more lash to be on the safe side.)Make sure to re-read the procedure for setting valve lash carefully, since you likely did something wrong before. Most likely you set the valve lash for number four when number one was at TDC and for number three when number two actually was. This is the usual mistake. There's an easy last-minute check. Both (inlet and exhaust) rocker arms should be loose and clatter a bit when you wiggle them at TDC with the rotor pointing towards that cylinder's HT lead on the cap. Once you get a start, reset the other side too, just to check. If you really did only change one thing at once, and it was actually the valves, you will get a start. There is only a slight chance that something else went wrong coincidentally. But a lot of guys can make themselves think they only changed one thing when they actually did other stuff too. So if it doesn't start, ask those kinds of questions. Did you tinker with the dizzy when you set the lash, for instance? All you should ever do is take the cap off and put it back on carefully. Then look for proximity. Did you accidentally knock the hot wire to the coil off? That's in the same region. Is the brake booster hose loose? The EGR hose? It's going to be something you did whether you like it or not. Denial is not a river in Egypt and not your friendly friend. Even removing and replacing the dizzy cap can be done wrong if you really try. The old science lab rule that you should never ever change more than one thing at once unless you can't help it applies to auto mechanics too.