Jeep wrangler 2.5 standerd turns over has fuel but no spark checked all relays and crank sensor computer is shuting down asd relay as soon as key is on. what does pcm look for when asd relay is not powered on? computer is shutting down asd dont know why? help please.

If its cranking fine you have one of two problems either your not getting any fuel or you have no spark. When toy turn the key to the on positron but don't crank the car lean back and listen for a whirling sound that is your fuel pump. If you don't hear anything is probably not working spray some starter fluid in your trottle body if starts you now know your problem. If the pump is working you need to check for spark one way to check is pull a spark plug wire off the plug plug it into a spark tester and crank it if you don't see any spark the problem may be your ignition module. Hope this helps you

ever get a full 60k mile full tuneup this decade, no ? really?
the first tests are,.
is the ASD relay dropping out?
and is there DTC errors scanning the thing with any obd2 scanner made.
1:key in
2: scanner in. and on, it talks ok.
3:crank for 5 seconds
4: release key, not off, is scan tool puking DTC errors, BINGO !@!!

the 8 ways for ASD to drop

http://www.fixkick.com/Jeeps/ASD.html

if the ASD does not drop cranking...>>>????
check spark now. at all cylinders, no engine stated.
check fuel pressure
check engine compression.
all that good, crank with test fuel
if engine flooding crank with wide open throttle to clear the flood.

is this the 4.0L???

which engine? (asked now 1000 times, only 2 ever answered)

tune up time, spark parts, rotor to plugs. filters. both.

its called a 60k mile tune up solves most.

my guess, is its misfiring or

is this the ASD relay dropping out then back in, as driven.

jerked before and after CKP sensor, did you know its the last thing to fail......

see the list of ASD drops.

misfiring, can be felt, its like a misfiring chain saw, ever here a 2 stoke misfire, ratta, tata ,tat?

some call it jerking, its not, is misfiring. (3reasons ) and 25 causes.

but jerkin real, like if you cut the ignition that is and instant bog.

but if you off the key and back on , fast, that be a jerk

that is total power loss. not misfire. its loss spark and fuel.

and jerks hard.

so does loss of 12vdc to the EFI system.

so the first step is to see if its the ASD relay dropping out.

on all jeeps.. 93 to now.



ASD



http://www.fixkick.com/Jeeps/ASD.html



automatic, shut down. (relay and EFI logic)



key point, the ASD will kill the engine, if fit sees spark is bad.

so its a chicken and egg deal.

here is the logic.

key on , crank , ASD closes, fuel injects and engine starts

then dies in seconds. or runs full time.

note that if the ECU sees spark dead, it cuts spark.

Sounds odd , huh. but is NOT.

this relay stops all car fires. (caused by this protection not in place)

which engine???????????????????????????
ASD is tricky on jeeps.
The Auto shutdown,relay.
what is it , how does it works is covered in the fsm. read it.
http://www.jeep4x4center.com/knowledge-base/index.htm?utm_source=cj#service
The ECU runs this RELAY, and if the ECU sees a gross error
it shuts this down, and the schematic there is clear as to what.
both spark and fueling.
here is what can drop it out.
1: crank sensor.
2: cam sensors or TDC ,etc.
3: sees spark dead or weak.
4: Immobilizer active. (failed)

as the book says , make sure spark is good for the 2 seconds cranking. (not after the 2seconds)
the ECU is programmed like this.
user cranks.
ECU creates spark,, using the crank/cam sensors at the time base
for 2 seconds
if the spark read back fails or the 2 sensors fail, the ecu shuts DOWN.
this is for fire prevention.
most other cars just cut the injectors, but not jeep
the drop the MAIN ASD relay.

using the check engine light flash codes, you can see which of the
3 failed, cranking for 5 second and releasing the key on all cars.
1996 and newer a scan tool is use to same effects.

now the 64,000 dollar qustion,
see page 8w-30-4
why does the ASD KILL THE IGNITION coil. easy.
1: it only guess it 2 seconds to make spark
2: if it cant,. it then drops the relay. killing fuel too.
3: this prevents the the crash and burn you see on TV.

so its 2 second permissive system. (or 3?) i forget exact seconds, its in then book and is short.
many dont know this. but is a fact.


now the flash codes.
crank for 5 seconds while in flash code mode
see emmisions page for how.

flash code 11 drops the ASD ! (cam or crank sensor dead)
code 54 cam signal dead?
code 43, spark bad.

what makes you think it has one?
1st check all fuses in both boxes
then make sure CEL glows, key on, NO CEL means NO EFI power.
Check engine light = CEL (MIL, mech named)
may be the tank wire connector fell off. (2nd check)
why not let the insurance shop fixing it , find this???
or not insured?
if you are hit the other guy pays??? rear ended are 99% other guy at fault. so.....
the first test is fuel pressure (a the fuel rail)
see TJ jeep here, read the fuel schematics, its clear.
only need a fuel pressure gauge and a voltmeter to find this.

http://www.jeep4x4center.com/knowledge-base/index.htm?utm_source=cj#service


its a jeep, the first thing you need to do is see if
the ASD autoshutdown relay is closing key on, cranking..????
if that dont close, all else is just window dressing...

fuse 12 and 23 kills fuel pump and ASD kills fuel pump.
the fuel sensed level goes direct to the PCM..

now the secret ASD what is it what does it do and work.:???
1: it cuts injection if spark fails or CMP or CKP fails.
that is its #1 job,
it closes every time you crank,(click) and if spark is good in 2 seconds
it stays closed, if not it drops out. any scan tool can see why
by cranking for 5 seconds and look for good cranking RPM (250?)
and no DTCS for crank or cam sensors dead.
this ASD is really the anti crash and burn relay.. in truth.
ACBR . lol.\
on other cars the PCM does the ASD job. directly. but not jeeps.

the inerial switch is for AIR bags, SRS, not pump
the electrical circuit shows one extras switches.
best i can tell, 100s of schematics... it have to be fuel only switch
non electric, go to jeep.com and look at fuel lines parts drawings
for free any time you want for such a valve.
i have one car with a anti roll over switch but is mazda. (fuel)

use the link above and online parts store to see all fuel related parts

1:fuel pressure to rail at spec? cranking !!!
2: spark , got spark
3: got injections?
4: PCM Scans dont show errors for 5 seconds cranking?

a fuel pressure gauge is $20
if pressures ok at fail, then it s NOT PRESSURE problem
(physics here)
you could by a scan tool (obd1) and see what happens at stalls.

one way to find stalls for sure pre 1996 is to measure voltages
on the ASD relay (the stall relay, LOL)
it if drops just before the stall that means the stall was
ECU COMMANDED.
and if the ECU commanded it , it knows why and will tell you why.
if the stall is not due to ASD drop
then its may other causes.
when you said it had no spark, i bet $10 you did it wrong,?
takes 2 persons, one at key other testing
if not you can NOT run from key to spark plugs, in 2 seconds
the ASD drop out rules.
yah cant
rule 1: key on and see the ASD close, (voltages)
it must close for 2 seconds cranked, must
and just stay closed, cranked, or if in 2 seconds it drops out
'that means the ECU dropped ASD for CAUSES, 1 to 8 reasons
the VTSS reason is not it, your car has no Immoblizer. feature.
http://jeepdied.com/no-start.html

here is a list
engine bad, low compression on 1 or or cylinders. (ask how)
spark is bad, ever get a tuneup this decade? FULL(spark parts)
ASD dead.
ASD drops early
ASD can drop at 80mph, so, ASD is always suscpec
loss of 12vdc power to the EFI system at any time it will stall.
can you save the stall with fast right foot, this test is like magic
in the diagnosis world, can you?
is engine flooding spark tips soaked, x4?
use wide open throttle to cut fuel cranked clears all floods i jeeps
(baring injector leaks sure)

what is ASD (all jeep stalls, read this first)
what does it do, and how, and why,
are all here
http://jeepdied.com/ASD.html

Check the ASD Relay! Try pulling the relay, look on the side of the relay and it will have a diagram, your looking for the two main hot feed wires, one will be 30 and the other will be the one straight across from it, I can't think of it's number.
Anyway, get a short piece of wire and clean each end and bend it so it will fit in where the two prongs of each of them numbers (30 and **) went and try to start your Jeep.

Before you insert your wire into the slots, make sure you pay close attention to the diagram and how the relay fits into the slots!
By the way, this ASD Relay is located under the hood in the main fuse block.
My guess is you have something causing it to shut down that relay or possibly a bad relay, if the relay is bad you can try swapping it with another relay right there just make sure it is one you do not need to make the Jeep run like the a/c relay.

You don't have one on there. Pump is turned on and off by the automatic shutdown relay and the pump relay. The crank sensor signal keeps it on. If the asd relay does not get a signal from the computer (from the crank sensor), it turns off the pump relay (and spark).
The pump should run when you first turn the key on. When you start the engine, if the computer gets no signal from the crank sensor it will shut the engine off (no fuel, no spark = off)
If when you first turn the key to on, you can't hear the pump, likely either the pump has failed (check power at the pump harness) or the relay is bad.(swap relay for a known good one and try it).

USA car
what engine???????????
wiki
2.8L VM Motori RA 428 Diesel I4
Complete engine specs[show] 3.6L Pentastar V6
Complete engine specs[24][show] 3.8 L EGH V6
times the starter will continue to run until key is turned off.
that is starter relay bad or the puter running it gone nuts.
or bad starter
next time when starter latches up, pull the relay
if it kills the cranking its bad relay or puter
if not, bad starter. all in 1min work..
and a very very serious first ORDER fix first problem
runs on test fuel. but you failed to keep it running for the 2 -3 second JEEP RULE.
if you had here is the results. (logic) hard.
1: i can keep it running with spray need a video?
yes, means ASD is not dropping out
2: no? ASD is killing the engine on purpose. and scan tool told you.

cranks no start
you said,
"No codes." if really true , there is no fuel pressure.!
if not true, its done wrong. so scan correctly THIS time.
is the skim light glowing in the dash cluster, if yes, it will not start
by DESIGN. SKIM is the immobilizer and DOES!

you must scan WHILE l its failing, not after, WHILE.
HOW TO SCAN correctly on JEEPS, (no starts)
key on, see scanner working? now, it must, if not ask.
crank or 5 seconds, (1 potato , 2 potata, 3,4,5.
release key, ( 4 and 5 are overkill but why not?)
do not turn key off or say 2 minutes, get PCM time to REPORT.

scan (2008 or newer scan tools work, CAN-BUS certified)
the tool then tells you why the ASD RELAY dropped killing starting (by DESIGN)
try to know SKIM is and option, so.... me blind can see car
http://jeepdied.com/ASD.html

runs on test fuel longer that 3 seconds, by hand, means.
all is working mostly, the fuel pressure gauge needs a jeep hose kit to work so/....... the pump needs power to work,



now the acid tests
i have 2. acid tests lacking a real scan too;..
spark timing light connected up.
you crank and spark dies, AFTER 2-3 seconds into crank/start
cycle means ASD dropped.
connect meter to injector 12vdc power feed its a daisy chain
12vdc dies, at 3seconds of crank, or dies
at 3 seconds of running,
if true PCM did that , and is ASD drop doing that
running any jeep for 1 second on test fuel is a waste of time
it tells too little
learn that jeeps can drop a ASD at 100mph
any time it wants. and only scanning while it drops
tells you why, unless the SKIM lamp glows,

I would check the crank sensor. The computer will shut down completely if the crank sensor is shorted.