It's getting fuel, the injectors are injecting, the spark plugs are sparking.
When I run the engine enough to heat up the exhaust manifolds, #6 gets hot enough to burn me, but the manifold is not hot at 2 and 4. My conclusion is that these cylinders are not working, or not working optimally. The engine doesn't run well enough to idle, and the unburned gasoline comes out as black smoke.
I acquired this van from a tow lot after somebody drove it for about
10,000 miles without an oil change. I make this guess because it used to belong to a friend who maintained it well, but it had 10k on the odometer that was put on after he sold it. And it has ugly oil.The engine produces a mild clattering noise like a stuck valve lifter(s). It doesn't sound like a bad crank bearing.
Is it possible that the valves are stuck enough to not operate, rendering these cylinders inoperable? What other factors could be causing this problem? I've analyzed and fixed the fuel and ignition systems, and I'm 99% sure they're working great. All that's left is the possibility that there is something wrong mechanically. If it were a cam timing problem I wouldn't have some good cylinders and some bad, so it must be something local to one or two cylinders. Any ideas?