Quick question, on a cold start I have a slight misfire at around 2,500rpm on anything other than extremely light load. Once I get above this RPM there is no misfire.

I've recently changed the coil, ICM and spark plugs but nothing has solved it. It only happens when the engine is very cold and goes away after around 5 mins of running. Once the engine has some heat in it, it doesn't skip a beat and pulls to redline with full power.

I haven't had time to check anything yet, but I'm looking for any ideas on where to start with what it could be, cams jumped a tooth etc? The engine is a JDM B18C from an ITR.

Cheers.

 

Also replace the plug wires, distributor cap, and rotor.

Any CEL codes?

 

I've replaced the cap and rotor, only thing I haven't changed on the ignition side is the plug wires.

No CEL codes and nothing is present in Hondata which would raise suspicion.

I have had someone mention to me that it could be the headgasket starting to go bad, I've not had any experience with a faulty headgasket but is that a possibility?

 

Replace. Also check the ignition timing. Then go from there.

 

I'm having the same exact issue on a b18c1. Changed everything ignition wise and still no change. Someone did mention to me also about a leaky head gasket that seals up when it starts to get warm.