I have a 93 civic 1.6 with a dead cylinder. I drove it in the morning and when I started it in the afternoon it had a dead cylinder. I replaced the cap, rotor, wires and fuel injectors. Where do I go from here?

 

Test the compression.

 

30lbs with engine started, injector disconnected.

 

Test the compression with the starter only, don't start it. Take out all the plugs and disconnect the low voltage wires to the distributor to prevent firing the ignition into an open circuit.

It sounds like that cylinder is about zero. The next check is to take the valve cover off and make sure all the rocker arms go slack when they should (valves closed with cylinder at TDC). If it's not the valve adjustment you have an internal mechanical problem and the head will need to come off to check further.

 

Leak down test coming out of exhaust.

 

30 PSI is awful low. Like mk378 said, I'd next pull the valve cover off and make sure all the rocker arms go slack. (valves closed with cylinder at TDC). If that's not it, you'll likely end up pulling the head to look for other mechanical problems.

The leakdown results you're stating seem to point to a possible valve issue though, so hopefully it's an easy fix (compared to pulling the head and whatnot, at least....)

 

Strange how it was fine one moment and when I started it later on the problem was there with no previous warning signs.

 

It could be a stuck valve (which can easily happen 'suddenly' like that, I've seen it a few times on bikes). Or it could just be horrid timing and something worse. :/ Unfortunately until you tear into it, I don't have any other ideas, myself at least.