98 Tracker Sluggish, misfire

[fixkick]

98 Tracker 4dr 1.6L 16v 5 spd 4x4

Hello all,

Bit of vehicle history, Motor re-built 200 km ago, transmission swapped to 5 spd from 4 spd auto.

Recently replaced

Plugs (NGK Iridium factory gapped to .032, I changed to .028)  (yes set tight then it wears wider , J GAP plugs only no  2J,3J,or gapless ever)
Wires (Belden)
Rotor (Napa Brand?) (not the kind that fits on 3 ways or you see the dizzy error told by you)
Distributor cap (Napa Brand)
Egr valve
Fuel pressure regulator (ouch stuck open )
Fuel Filter
Air filter

My tracker seems to have hesitation and a misfire once the rpm is around and above 2000 rpm.
Also under heavy load it seems to want to stall (off road) coming out of a deceleration.
I replaced fpr because it failed the leak down test. Would pressurize to 36psi key on, key off immediately to 0psi. (passes leak down test?
Shunt test proved it was stuck open. New one working properly.
Idle at 780-815 according to live data, ECT 81 Celsius (OBD2 scanned)?
Also, to get my ign timing set to 5 btdc the distributor is almost maxed out of adjustment CCW. Probably close to 15-20mm away from center.
My next step was going to be confirm timing is correct (Cam/Crank/Dizzy) then injectors. Oh, I also checked the vacuum and its a stable 21 inHG
when I hit the throttle it goes to 0 then up to 25ish and settles back to 21. Not sure if that helps. (Does , show CAT not melted and no  burned intake valves)

Thanks anyone who's able to help

Still misfires,  ?   (bad spark, bad engine or flooding) are the 3 classes of misfire. (causes many , even sensors reading wrong to ECU)
Nice tune up done, that will pay back....
timing set? (spark) with timing freeze jumper? inserted in DLC connector?

is the cam belt jumped 1 tooth,  that would instantly cause spark timing to go off that much. and distrib, hitting end slot.
no scan tool?,  OBD2, is easy to scan , on all cars in USA 1996 up.  all are OBD2 here (our lil' invention)
A real scan tool will show at hot idle in CLOSED loop status, if not we can work this problem too , even first.
DOES:
key ON cluster CEL lamp glows, it must
and start engine it goes out,  right??
Good 82C good. STAT not bad. ECT not BAD, good.(seen via OBD2)


compression at  all 4 per below,  at sea level  are you and do this with throttle blocked open, 1/2 to full by hand or foot, let it peak.
My 97' pulls 185 PSI min. dead cold. (a new head) later  and  hot it does 195 PSI(is spec)
if the belt slips the PSI drops low on all 4.


is the front crank end pulley,  17mm bolt set to 94ft/lbs and never loose?  (I can this the DAY1 CHECK)

clean the MAF yet?,  use plastic safe spray min. 8" away not closer clean the hot wire inside  ,if dirty , it will read low, and huge power loss. (lean)
The MAF has  dash 58B00 marking on side . is yours marked like this? and not fake? MAF:"
58B00 is real suzuki Part Number (PN)
the E5T~ is contract code from Suzuki to maker Mitsubishi in actual JAPAN. That tag must be there, or is fake maf. for sure looks shinny and new MAF. super shine ?



the last poster here (not you) had a FAKE MAF,  at $20 price (100's flooded on ebay) and his reads too HIGH and engine flooded rich and misfired, (failed smog test)
never use cloned mAFs. from CHINA, they are pure CRAP !
only run those seen on rockauto,  they have no fake mafs there, (they know fakes fail )
a good maf is $200 not $20 , <<< best clue of all is crazy low price, if it looks to hard to believe IT IS.
Normal real MAFs read low, when dirty , only clones go high, and real shocker to see that nasty bit of bad ACT !  wow ah !

your vacuum test seems good for sure steady and drop to 0.

one more trick , not a panacea test but
remove 02 sensor, elect. plug.
this might cause  super rich engine to go learn and stop misfiring, or less.
or if 02 sensors dead and or stuck at 0v , the connector pulled causes 0.45" (1/2 of scale) and my cause less misfire.
the other cause of good 02 sensor failing(and is not) is the exhaust header #4 tube, classic crack seen here.

a good scan tool we see this, we see the O2 swing,  and not stick low if does engine goes rich; AFR, air fuel ratio. this is what CLOSE Loop does, hot engine, idle.
and at light steady foot cruise,  B1 bank 1,  sensor 1 is front, S2 is rear and do not care what it does now. not full swing.  this is called trim too.
Trim (STFT) controls injector modulation Pwm pulse widths.
The  02 simply corrects natural MAF errors,  and others to. but simply this is fuel trim happening. dirt cheap tool show, here is to prove cheap tools work
at harbor Fright(pun)  my far better tools work to and do same.