My H23A1 engine runs great at idle but when it warms up Cylinder number 1 & 2 misfire. Compression is ok 180 psi in 3 cylinders and 175 in the other.
ANy ideas?

 

Pretty generic things to check are your spark plugs, plug wires, cap and rotor, and fuel injectors.

 

take the plugs out and inspect them. If those check out ok, remove distributor cap and check for corrosion on the rotor and cap points.

Also, when is the last time a valve adjustment was done?

there are all sorts of reasons why a cylinder will misfire. Either take it upon yourself to do a little digging or take it to someone who knows diagnostic.

 

I installed new plus, distributor cap, and rotor button. It runs great when its cold but as soon as it warms up its starts skipping. Cleaned the EGR, and check ed the IAC.

 

Problem solved. I ran some top engine cleaner through the brake booster vacuum line and cleaned out the IAC. Running great now. Intake was really gummed up.

 

if problem comes back check plug gap, always use oem spec plugs ( i prefer bosch) and replace wires.