I have a 2001 Honda prelude that has a Robson misfire on all four cylinders and idle bounces when it’s cold, not sure of they are related but I’d rather say more then less, I have checked so many things to try and fix this, icm, plug wires, spark plugs, cap and rotor, iacv, fuel filter, timing belt/water pump, tdc and cps sensors, egr valve, knock sensor, and many more things have been replaced, I have taken it to a shop before and they couldn’t find a vacuum leak (they may have missed they aren’t the brightest there) the only weird thing is when I take out my stock ecu and put a pherbnet ecu that was tuned from another prelude the misfire is gone, he ran that without an egr valve, so my mind can only think of air fuel problems but I can’t find a single thing, so I am requesting help to find this issue, it mainly misfires when under acceleration

 

Fuel pump? injectors? EGR valve bad or EGR ports clogged?

 

egr valve is brand new and I haven’t cleaned the ports