Does a fuel misfire exist? Is it as 'violent' as a no-spark misfire?
If my fuelling is out then I know I get poor performance/throttle response, bogging down (it goes 'wuuuuuurrrrrrr' but doesn't accelerate) but never a on/off misfire. Is this misfiring I'm experiencing or just leaness/richness and how lean/rich do you go for misfiring to occur?
Thanks if you can fill me in!
A cylinder misfire is a condition most people often refer to when the majority of the air/fuel mixture in a cylinder fails to ignite resulting in no perceptible pressure rise (no discernable engine torque output). The cause can be from no or very weak spark, air/fuel mixture ratios that are out of the combustible range, or any of the two in varying degrees.
If an OBDII diagnostic trouble codes of type P0310-P0312 is thrown, then it would probably be a good idea to check the ignition first. Sometimes a misfire can be intermittent too.
A misfire can usually be felt, for example, by a brief interrupt of power output in some cases.
By your description, you may not have misfires, but you may have near misfire conditions.
Also note that it is not enough just to have proper amounts of air and fuel in the cylinder. Air and fuel inside the cylinder must also have to be mixed sufficiently to form mixture ratios that are combustible. If the injectors are too dirty, mixing may be compromise for example.