Yj dies while driving

DOWNS said:
When was the last time the battery and ground cables were replaced? Too many times, owners chase their tails and throw parts at running issues when the battery and ground cables have never been replaced. I've cut apart cables that looked good on the outside, but the inside of the cable was a tube of corrosion. Battery cables are a consumable item. They need to be replaced periodically. All the sensors on the Jeep work on a 5 volt reference signal and are very ground sensitive.

On top of that, we need a full set of "vitals" for your Jeep.

Fuel pressure, which has been asked for a few times and we still haven't seen any numbers.

Compression Test

What do your plugs look like?

You're going to have to use a more systematic approach, or you're just going to be throwing part$ at the problem until you get lucky.
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Thank you, i am going to see the mechanic today, keep you posted!
 
My 93 Cherokee did this, it turned out to be the catalytic converter. When it got smoking hot no air was getting through, engine would shut down. I drilled a bunch of holes in it to get me home, worked. Replaced it and it never happened again.
 
95yj stick 4wd, same as mine, exactly, and I have all books on it , in print.( AND HOW TO USE A VOLT METER , IS WIN)
so you did see rail pressure dead ,1 time at no start, so bingo, no fuel.
ASD relay is 1st.
33 (55= end of message) 33 is open or shorted clutch.A/c COMPRESSOR BUT IS MISSING, IT.
Air conditioning clutch relay circuit open or shorted < fsm WORDS.

YES all fuses good, not loose or rusty or nasty. all clean and good. is first.
the ASD is next.(VOLT METER to it)
the ASD shuts down the pump (and more) if it sees any of this.
  1. spark dead or cmp or ckp dead. it cuts asd off line. (this is for NO CRASH and burn as seen TV)
  2. output of ASD is pcm monitors, if the 02 sensor (heater wires) short or the sensors (loves to) short the ASD is dropped fast.
  3. all things on output of ASD must be good not shorted ok is this clear, the FSM shows all things there.

ASD DROPS IF IGN COIL SHORTS (PRIMARY)
ASD DROPS FOR INJECTOR COIL SHORTS, ANY
ASD DROPS IF O2 SHORTS (HEATER PINS OR WIRES TO THEM TOUCHING EXH PIPE)
CMP DEAD CODE 11 OR 42, DTC
CKP DEAD.
MONITOR PIN 24 OF THE ASD FOR DROP OUT KEY AND CRANKING ANY DEAD JEEP
THE FEED IS CALLED A142 , PAGE 8W-30-8 IN FSM
THE SILLY ALTERNATOR USES THIS WIRE AND IF SHORTS BINGO ASD DROPS. pin 2, rotor exciter wire shorted.
PCM SHUT DOWN ASD AND PUMP BOTH (SAME WIRE)
always cranks fast but sometimes does not start, and we say fuel pump off line

need the free FSM ask.(real) not fake.
 
if the FPR goes crazy , gee its old and they do.
fuel pressure can go to 60psi and sure the CAT melts, sure shootn/
called flooding , old skool(sic)

not saying we know what is wrong, just how to test, want to test using real tools and find it?
you lost spark too I bet but only the first test, engine assumed good,.
PCM cuts fuel if it sees spark dead by DESIGN(logic pcm), (and laws on crash and burn avoidance)

yes the sad part (below 1996) only DRB tool can see the asd DROP CAUSES. THE TOOL NOBODY HAS.
So we disconnect things
alternator jack
o2 sensor unplugged
ohm out all injectors for 10 ohms, 0 is shorted.
check fuel pressure rail, 60psi no good , 0 psi failed., and key on pressure, 3 times, see
31psi idle
see 41 key on 3times, (spec is (8-10 psi) higher than running PSI)
if fuel leaks on FPR nipple it is bad.
the map hose not falling off or cracked. or on wrong port for vacuum,
 
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