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Over the past month my 98 honda civic ex has been throwing a CEL with a misfire cylinder 1 code. Things that have been replaced to date is a new fuel filter, NGK plugs and wires, a new dizzy and radiator. When you start the car it has very rough idle and it seems like it wants to cut out, but then the rpm's jump up and idles normal. This morning I checked compression on all 4 cylinders and the readings are as follows:

Cylinder 1 compression: 195psi/ Injector 1 12.3ohms
Cylinder 2 compression: 180psi/ Injector 2 12.3ohms
Cylinder 3 compression: 172psi/ Injector 3 12.3ohms
Cylinder 4 compression: 184psi/ Injector 4 12.3ohms

According to manual maximum variation between cylinders is 28psi

Standard psi is 184
Minimum psi is 135

I also checked the resistance on all injectors and they seem to be functioning properly. So i do not believe the head gasket is blown. Also there have been a few times where idling at a light the temperature will start going up but then as soon as you start driving temp will go back to normal. Any help would be greatly appreciated!!!! Lost and not sure where to go from here..

 
Rep Power: 518

Got freeze frame data you can post? That might help.

Clue.


Losing antifreeze?

Wildass guess: Sounds like maybe the cylinder(s) that misfires is getting taking in antifreeze after the engine is shut off, then gets its sparkplug wet with antifreeze at startup and it doesn't fire until it gets dried off.

 
Rep Power: 0

Will post tomorrow with freeze frame data. Also checked plugs and they are dry from any antifreeze.

 
Rep Power: 0

Losing very little antifreeze, and I mean a little..

 
Rep Power: 518

You would have to catch it in the act (so to speak) of misfiring.

Start it up, notice it misfiring, shut it off before it clears itself out. Inspect the plugs right then for fresh wetness at that time. Is it gas? Coolant?


Just thoughts.....

 
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I repair these heads for gasket leaks daily.
A quick check for your symptom is to pull the spark plug on the problem cylinder and move the piston to the top of its travel. Shine a flashlight into the combustion chamber an look for clean spots on the top of the piston where coolant pools and is burned off. You'll see an erosion of the carbon build up that looks lighter than the rest of the top of the piston.
The only real way for you to confirm this leak is to pressurize the cylinder at its top dead center (preferably with a leak down tester) and attach a coolant funnel to the radiator. Pressurize the cylinder and look for bubbles (in the coolant funnel) after a small period of time. This will conclude you have combustion gases leaking into the cooling system and have a head gasket leak.
You must perform this test while the engine is hot. This test is for small pesky leaks such as yours.
I'm guessing you're lacking these particular test tools. Which is why I suggest the piston washout check. Not exactly the best way to tell however.