Im almost at the point of getting a honda!

Pull the valve covers & watch the rocker arms when running to see if they are fully opening the valves.

Did you check the timing chain marks? This probably isn't the problem though since you said it runs fine when cold.

When you install the intake make sure you put a little silicone around the intake ports.

Also, like others have said check all the engine wiring. I would just replace it if it's original since Evans Wiring has them for around $100 new.

Good Luck