its EFI they dont vapor lock , like carbs, not at all.
so lost spark, test spark on all cylinders.
if you lost it all , you dropped the ASD relay?
if you have spark try test fuel,. (spray)
im now posted this everytime , no spark. my 3 time now, trying to reach a new record..... LOL
no scan , tool so on your car , you do the CEL falsh code deal.
see in the fsm under emission+diagnostics.
http://www.jeep4x4center.com/knowledge-base/index.htm?utm_source=cj#service
quoting my self.... on this forum...
posted to fixya many times
ASD "automatic shut down relay"
what is it?
it cuts fuel (and spark) if the PCM thinks, there is any danger of crash and burn.
The PCM drops the ASD for many reason, this list is all years. (some are missing on early years)
1: sees the spark weak or dead on the ignitor or coil primary pin. (it knows spark is bad)
2: Crank sensor bad. or misfiring. CKP
3: cam sensor bad, or misfiring , CMP.
4: ASD input read back pin fails. (PCM commanded it but it refused to do its job)
5: same ASD output fails. i commanded it but the relay is bad. dead.
6: Immoblizer active. (failing or bad key etc,)
if the ASD drops driving or even parked idling
one of the above caused it.
the ASD has engine startup logic that is unique to JEEPs.
you must crank with in seconds or the key on is ignored by many jeeps.
you crank and the above 6 must not fail during the start event or it cuts the ASD.
note carefully, if spark is bad cranking, the ASD cuts spark 100% more dead.(funny, but very true ,read the ASD schematic)
you only get 2 seconds to get the 6 factors true or the game is all over.
if when driving, it sees one of the 5 fail, ASD drops.
in fact ASD can drop then come back. while drive, people say it cuts out.
if true, using any dirt cheap scan tool will show why,
DTCs tell you. Cmp /ckp or spark dead.
pending or live DTC
freeze frame, dtc will show what failed.
and even seeing RPM drop like a rock, faster than any crankshaft can spin down, dig?
or loss of 12vdc power to the PCM , does all this above. DIES.
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