98 Jeep Cherokee Laredo 4X2 suddenly dies .....

Start with the basics, spark, fuel and air, take it from there

It could be that your crank sensor needs renewing

If the starter dims the lights noticeably when activated the starter is the culprit. If it got stuck and ran with the engine the bearing will cease and the starter will not turn. Dry bendix and or bearings will prevent starter to swing. If the rotor is touching the field coils it will short and will not turn.

long post.
ill reduce it for you.
misfires. (is RPM below 700 then misfire can be normal) for idle speed controls dead.
ISC the isc controls speed, of idle,.
mine stuck like zillion times, in 400k miles. endless.sticking
mine was a tiny gutless stepper motor drive ISC valve.
the cone valve is side gets nasty and sticks (
(PCV gases caused as seen on all engines)
i clean it.
the proof is the easy press of right foot easy raises idle back to 700rpm and engine stops misfiring.
ever get a tuneup this decade or running spark parts 500,0000 miles
for the new world record.?


now the tricky part of ISC, , fully explained in the SM serv. man.
the PCM learns its behaviors.
it learns all hot start settings and cold
so when you key on, it goes to the correct HISTORICAL spot.
if it can move there(sticks) engine car race.
or run too slow,
cold start would be worse, as hot isc is more closed
so if sticks there closed, the next cold start will be horrid
some newer manuals telly you to add 5% throttle if car is hard starting this is so common.

clean it. end story.
ISC

Air temp and humidity level can change mpg calculation two tenths. BUT, that does not account for the huge disparity in your numbers. You may have something wrong with the trip calculator or, there may be a leak somewhere. Have your codes scanned. MPG can drop suddenly if an O2 sensor fails.

Fan relay or a temp sensor

Try some "heet" , STP gas treatment or the like. sounds like you might have some bad gas.

Check to see if the fuel pump is running after it shuts down...could be a relay or the pump itself (overheating internally) Checked the fuel filter yet? Some crank sensors need to be shimmed. If it's too close to the flywheel even though you recently changed it, if it's too close to the wheel it can fail again. May not be the case but worth checking over. Also check the ceramic resistor on the left fender near the master cylinder if you have one. That too can cause problems.

I have a 1996 Grand Cherokee - the same problem, except my interior lights flash on and off at the same time. Did you get your problem solved?

OIL PRESSURE SENDING UNIT ON MY JEEP GRAND CHEROKEE LAREDO 1999
WHERE IS IT LOCATED AND IS THERE A DIAGRAM OR PICTURE LOCATION FOR IT

ANY SPECIAL KNOWLEDGE TO PUT IN?