F18 B VTEC. I am kind of pissed of by the fact that no one can identify the problem even the big dudes in market.

Symptoms
1. Missing before 2k RPM not all the way but at some points.
2. If you drive the car once at throttle floored the car would badly and would require some slow driving.
3. Flat Spot after 4.5K RPM


What I have done:
Changed Injector (with their small filters)
Changed Fuel Pressure Regulator
Changed Ignition Coil
Changed ICM
Checked Spark Plug Wires for arc
Cleaned and sealed throttle body
Checked MAP and TPS
Changed Rotor
Checked Distributor Cap its fine
Mechanics say the fuel that returns to Tank has sufficient Pressure. They never used Gauge because no one does here. They inserted a pipe with FPR and into transparent bottle.
I saw continuous stream of bubbles in the fuel that exited from rail.

This is ODB2B car so it does not have timing adjustment. However i plan to check if timing belt is slipped or not.

I have googled enough and since past week I have been seeking solution to this problem. Please help me.
Thanks

 

If your replacing ignition coil and icm you should go all the way and replace the inexpensive stuff. cap, rotor, wires, plugs. For a long shot you may have a clogged catalytic convertor. I've seen it happen before. If you unbolt it and the car runs better its a sure thing.

 

I would try unbolting the Exhaust tomorrow.

 

If the spark plug wires are old, or even if they are new, it doesn't mean they are flawless. Had a set of new NGK wires with one wire that had a small slit in in it that was unnoticeable.

 

What about bubbles in duel stream are they normal

 

Went to Shop Tested Fuel Pressure.

25 Psi on Idle with Fuel Pressure Regulator vacuum Attached
40 PSI with Fuel Pressure Regulator Vacuum Removed

Following are the test results from Scanner




I would be adjusting the TPS.

I am not sure about O2 m Fuel Trims and Spark Advance Values. Can you verify