2001 Ford Focus missing in cylinder #4

Thanks for your quick reply. Yeah, spark and compression look good. I'm wondering now if I damaged the injector when installing. It was tough to get in. Will be pulling it this weekend.

Very odd results today. In reply to your suggestion, ALL of the injectors have 12V with the key in run position (pulled off the connectors and tested voltage at the sockets), what could this mean?

Removed and replaced the injectors, they all look good (not damaged, I know they could still be bad but as I mentioned I changed the one in #4).

I misspoke when I said compression is good, I thought it had been tested but not so. On this engine, the plugs are recessed, with the cams on either side. My friend's compression tester has a hose with a swivel connection so we can't get it tight into the threads when we pass it down the hole. Is there an adapter or a different style gauge to buy?

I don't know, but I'm guessing that the pulsed ground is too fast for a multimeter and I don't have a scope. However, I'm a happy guy because after fitting it all back together it is running properly. When I had the injectors out I renewed the o-rings, which I (stupidly) did not do originally. Must have had a sealing problem. Thanks for all your suggestions.