2k3s2k

I have come across an interesting problem, in which I have no good logic to explain. Hopefully, someone can enlighten me.

2001 Civic EX, auto. Cranks over but won't kick or try to fire up. I can hear the fuel pump, so my first test was to check spark. Obviously it is a coil-on-plug system, so I removed the #1 plug and coil, left it hooked up and set the plug on the exhaust manifold heat shield to ground it. Not only did i get spark, but the car started and ran! Put the plug and coil back in, won't start. Left the plug in, but removed the coil, won't start. Removed #2 spark plug and coil completely, car starts and runs.. repeated for cylinders 3 and 4 with same result. If any one single plug is removed completely so the cylinder is open, it will start and run. plug the hole whether the coil is connected or not, won't run. When it does run, its not stumbling or struggling it runs smooth considering. What the hell is going on?? My only logical explanation is a ground problem, or possibly timing. Power source is not shared among all, as each plug has its own individual coil each coil sees the same amount of voltage regardless if you remove one from the system. The only thing they all share is the ground through the head. There is one ground wire coming off the head above the thermostat that runs from the head across to the radiator support bracket. It is in tact and appears to be fine. I do not see any other ground wires off the block, and can't find any diagram online that points out ground locations. With the number one cylinder at TDC, the single timing mark in the crank pulley is directly between the prong points on the side of the timing cover (there are 3 leading marks, follow by one single mark. The single mark is the one I'm referring to). Other thing to note: when i stop trying to start the car, the engine rolls in reverse before stopping. compression is 160-170 all across. Valve cover vent is not blocked. Anyone come across this issue before? Any ideas?

lazlong

According to the service manual you should have 135psi with a max variance of 28psi (163psi). With you ruling out several reasons, high psi and the engine running the way you describe it leads me to think there's a restriction (exhaust or intake) or excessive carbon buildup.

Are you getting any trouble codes besides mis-fire codes (P0300-P0304)?

2k3s2k

There are no trouble codes, checked that as well. The parameters my scan tool will pull up appear to be correct. I have the header open and the intake system removed to eliminate any possible restrictions. If you cover the throttle body while it is running, chokes and dies. My manual says a minimum of 135 and max of 184. I'm lost.. the scenario makes zero sense to me..

lazlong

Look for carbon buildup.

2k3s2k

Where? Where would carbon build up occur that would cause this?