1998 Jeep XJ, has no injector pulse. How do you diagnose if it is a PCM fault, or something else not allowing the PCM to do its job?

Here is your fuse box diagram on 2 websites.

Jeep Cherokee (XJ; 1997-2001) fuses and relays

Fuse Box Diagrams https://fuse-box.info > jeep > jeep-cherokee-xj-1997-2...

Fuse Box Location ... It is located behind the lid under the glove compartment. The location of the fuses in the passenger compartment: Jeep Cherokee (1997-2001 ...

'97-'01 Jeep Cherokee XJ Fuse Box Diagram

knigaproavto.ru https://knigaproavto.ru > ... > Jeep > Cherokee

Oct 7, 2019 - Fuse Box Diagram Jeep Cherokee 2.5L AMC 150, 4.0L AMC 242 and 2.5L TurboDiesel (XJ; 1997, 1998, 1999, 2000, 2001)

As I said in your last question, there are very few reasons you need to go near it. A good auto electrician with a professional grade scan tool computer can diagnose the ECM for faults in about 20 to 30 minutes. It is not a job for 'let's try changing this'. If it is bad, a new one needs a tech to install as it has to be programmed with the VIN Number and mileage and set up.
https://www.google.com/search?q=auto+electrician+near+me

..

low miles for age, a USA car? ENgine told at all and is and engine EFI problem.
5.6L V8 engine????????? NISSAN
all fuses tested good, skip NONE.
scan show not one DTC error right>?
no starts have 50 causes. guessing is super expensive and invites big time adding 2nd or 3 problem from just 1.
not old are all injectors bad? or just 1.?
the PCM fires the injector, and cuts them all for many reasons.
you did not scan the PCM after the no start event>?
all car parts stores sell injectors. uses and new and rebuilt.
I send them out for reverse flow ultr sonic cleaning,
they have 10 micron screens inside so must be reverse flow cleaned
so the engine starts and runs on spray instant start in a can?
3sec blasted to intake and runs for 3 seconds and the enigine sounds good try it 3 times to be sure that????????????????
if yes, we do check 2 or more things.
we use NOID lamp to see if all injectors pulse x8
or scope tested any scope works
and check injector pins for ohms good $15 dmm meter and bingo all are same ohms. 15ohms is common.
fuse 55 powers all injectors here, daisy chained.
the PCM drives all injectors (low ) with on board, PCM drivers.
there is no such thing this Injector pulse module at all , like we say in early 1990 or late 1980s, sorry NO SUCH THING
am not arguing names but the PCM runs all 8 injectors ALL BY ITSELF for sure.
nos scanning the PCM is a huge error. what if you had dtc codes for shorted open injector coils.
the PCM has 122 pins on 3 or more connectors
if input to the PCM are wrong he PCM cuts fuel.
if the PCM detects spark is hard dead, the PCM cuts fuel to prevent crash and burn as seen on TV (jive)
the PCm cuts fuel if any cmp or CKP sensor dies
see why I asked if all injector pulses are dead
and the p55 fuse is hot key on as are all injector pins hot key on?
the PCm cuts fuel also for IMMO failures of ANY KIND
the PCm cuts fuel for SRS system crash detectors tripped.
the PCM cuts fuel for any gross error of TBW.
THROTTLE BY WIRE HERE, IF SAY THROTTLE TV VALVE MOTOR STICKS OPEN IT FOR SURE CUTS FUEL DEAD.
F22 FUSE BLOWN GEE KILLS THIS TBW DEAD.
NO MORE DRIVING OVER KIDS NOW. OR 1BILLION $ LAWSUITS. AS TOYOTA SUFFERED AND WAS NOT THEIR FAULT AT ALL.

IF YOU WANT TO DO DIY, YOU MUST HAVE TOOLS.
A REAL SCAN TOOL
A FUEL PRESSURE GAUGE
AND ANY CHEAP DMM. $15 UP.
IF ALL INJECTORS ARE DEAD SAY SO.
IF ONE IS DEAD REPLACE IT OR CHECK OHMS FIRST.
IF NOT SAME OHMS AS OTHERS THERE IT IS BAD. FOR SURE.
IF ALL ARE DEAD NOW YOU KNOW WHY THEY ARE.
CUZ I TOLD YAH.


LEARN NOT TO GO TO STEALERSHIPS AND FOR SURE WHEN SUPPORT IS ZERO. !! WOW WHY BUY NISSAN? GO JEEP.
ANY ASE SHOP IN THE USA CAN DIAGNOSE THE CAR AND NOT WAX LAME LIKE THE DEALER DID.
PULSE MODULE LIES TOLD TOO.
POWER-TRAIN CONTROL MODULE IS IT.

I use SMP a top maker,!!!!!!
injectors are not some rarity ever. huge huge industry support.
case in point not RARE AT ALL.
AND REBUILTS AND LOST OF SHOPS THAT DO ONLY INJECTOR CLEANING LIKE NEW.
AND WILL TELL GEE INJECTOR 4 IS NOT GOOD.
IF IS,.

https://www.rockauto.com/en/catalog/nissan,2004,titan,5.6l+v8,1423033,fuel+&+air,fuel+injector,6224



WE SCOPE ALL 8 LOOKING FOR BAD WAVEFORMS
THEY ARE IN FACT PWM , MODULATED TO KEEP THEM COOL
A WHOLE OTHER LONG TOPIC SEEN STICKING INJECTORS ON A REAL SCOPE. I CAN EVEN SEE THEM OPEN? ON THE SCOPE
IF ALL DO FIRE RAIL PRESSURE TESTS ARE NEXT.
OR EVEN FIRST.
FUSE
SCANS
FUEL PRESURE
AND TEST ALL INJECTORS FOR CORRECT PULSING
IF ONE IS DEAD JUST SWAP WITH ADJACENT INJECTOR
NOT FLEX FUEL ENGINE NOT E85 RIGHT>
THE BOSCH INJECTOR DOES ALLOW E100
62640 STOCK INJECTOR (FLOW RATES) DO NOT NEED REPROGRAMMING ANYTHING.
THE COILS ARE 12-14 OHMS
0 SHORTED COIL
INFIRMITY I BURNED UP COIL
24 OHMS IS COIL DAMAGED.
WE JUST BE SURE THEY ALL READ ABOUT THE SAME 12.
I ALSO HAVE A NICE SONIC INJECTOR TESTER THAT HEARS THE INJECTOR CLICK PROPERLY.
NOID TESTS
SCOPE TESTS
SONIC NOISE TEST.
KEEP IN MIND THE PCM HAS HUGE FET TRANSISTOR TO DRIVE THE INJECTOR AND HAS 2 FAILURE MODES ANY SCOPE SEES IN 1 SECOND FLAT
1: DEAD DRIVER
2: WEAK DRIVER ,OVERHEAT DAMAGED.
OR 12VDC POWER ON OTHER PIN IS GONE, THE DRIVER SEEMS DEAD. AND IS NOT.

I worked on one with the same issue. Ended up being the harness burned at the rear of the engine on the exhaust. Burned wires going to coil pack and shorted when I moved the wires to the coil packs.

XJ 94
its not bad, wana bet? 90% are not.
(i used to fix them)
so the PCM,. the FSM book covers that.
why not read that.
JEEPJX
PCM is baD ONLY WHEN inputs good, and its outputs are bad.
(and outputs not shorted) !!!
(same or all computers on earth)
lose of power to PCM or ground
or bad power.(weak, or intermittent)


Got DTC errors , post them?
innova 3140 best bank for buck on 93-95 jeeps. !!!
that is a low priced scan tool

are you having ASD relay issues?
http://www.fixkick.com/Jeeps/ASD.html


see XJ 95 here (same i think)
http://colorado4wheel.com/manuals/Jeep/XJ/

page 8D-23
engine bay next to Air cleaner.

to diagnose any car, a real scan tool is best.
or you will need a full lab of meters and scopes. like me.
the scan tool show up things the keyon/off trick does not.
http://www.fixkick.com/Jeeps/jeeps.html#poor_mans-scan

If not pulsing, could be a bad pcm. The computer grounds the injectors internally for a split second to pulse them . If trash or debris is not making them stick open, buy a "noid light" for checking injector circuits. Plug it in to #1 or #5 and crank engine over: if circuit is working right, noid light will be blinking. If light is on steady, computer is not interrupting ground to cause pulsing.

No injector pulse at injectors:
a) check fuses
b) use scan tool to read RPM at PCM while cranking. Ask question specifying RPM PID data.
c) crank sensor/cam sensor/ign. module/wiring fault
d) stuff not plugged in properly
4) check fuses
5) dead PCM note PCM pulses injector ground based on sensor input, power is constant from ignition
how are you testing injectors theres something called a noid light auto parts store let you use them free you have to test it on the injector itself what did you car do before it died does it turn over but not start

Can you check that injector for pulse . May be bad wiring to pcm

Chances are you need a catalytic converter.

It could be a faulty pcm or wiring as you stated in you post. the pcm pulses a ground to the injector circuit allowing the solenoid in the injector to activate momentarily are inject fuel into the intake. if you give me the engine size. V8 4.7L or strait 6 cylinder 4.0L and i will post the proper wiring diagram for the fuel injectors to help you out with your battle

Have you tested the PCM fuse??