Misfire, but no DTC's?

[Fabricator]

driving cycles are not simple, like keyon , key off, key on, be nice if they had DLC jumper to do that, called, (driving cycle disabled)
but due to that , DLC are a pain in the bottom gasket.
btw, i will study your xls more completely later today.. before 6pm.

http://ge.tt/6gvplbp2

see chapter 3 part3) (down load , the view online fails for too big ) P0300 misfire, 300 means all 4 fail and all 4 random failing. (so is most time AFR RELATED) BUT THERE ARE LEAN AND RICH CODES
page 11 +
300 MEANS weak piston;rod/crank accelerations, means combustion was weak ,or spark failed, or injector failed. (in this case all 4 are weak)
seem the frame 15 engine goes lean, to me, best I can tell in, openloop.
ON THE DATA FRAME 15 , AT WOT THE O2 GOES LEAN AND THE MAF IS WEaK, CLEAN IT TEST THE MAF MORE CAREFULLY.

why is MAF weak this is the focus point. Will clean and test MAF
the injectors could all 4 be clogged (1/2 way) PO installed new injectors, but do not know where he got them from - will ask
from bad fuel parked over a year. About 1/4 tank left, car was parked for a few weeks before I got it
the injector balance test may fail. Will consult FSM for injector balance test

DTCs go offline, if fuel level is below 15% (Page 11) 11 to 14 (are p0300)
P0300 needs steady (steady TPS) to run the monitor, idle or steady cruise. the CEL then blinks on USA car, telling driver, your cat will soon burn up.even melt. Looks like I need to add some gas and drive this thing...
below 4000 RPM rule (300's)
causes
Huge vacuum leak or weak maf or only dirty maf.
I'd say engine is going lean. (02 off line , I cant see it go lean thanks to tools OBD2,silliness here) My scan tool fancy I can force or even loop on 02 readings live. and 2d scope view them)
the injectors weak? theory,/? one can add propane gas to IAT port. to see of bog or misfire ends. Want to try this
P300 per page 11,. has 2 times rule in this DTC,
even bad fuel can do this. super easy,
page 11 list them all.
bad fuel
weak maf
vacuum leaks.
injectors 1 ,2,3,4 all weak, (partically clogged, due to bad fuel)
lean or too rich misfire.
and spark must be good, (got new plugs? set to 0.028 inches, J plugs only no surface fire plugs allowed on this weak spark system) Plugs relatively new, and are J style plugs
fuel filter 22 years old, and 90% packed up? if fuel pressure drops at frame 15, BINGO, Fuel pressure goes to 43# when misfire is induced

DTC's set for 2 ignition cylces (so 1 run will no set many DTCs) in general, one has to read all 4 parts, (PDF) to see all rules, I just OCR mine to find "cycle"
they clear with 2 to 40 driving cycles.
its not low fuel pressure. (so we skip this and is super common)


no P0171 or 172 trim errors (part3, page6)
I dont see fuel trim landing on 43% or greater long-term fuel trim or over 20% short term.
does you scan tool have, O2 sensor graph viewer? (this loops the scans on B1S1. bank 1, sensor 1 front, and see if the sensors goes to 0v,? lean? stuck lean. Scanner does have a graph view - check of 02B1S1 shows cycling rich to lean - no flat lines, and appears to operating normally? - I have a video showing this, but might be too big to post here...
if yes, MAF is week or injectors clogged