My 1994 jeep grand Cherokee Laredo will not start or stay running.turns over but will not fire,but then sometimes it will.when it does start it runs very rough and will stall if I try to restart it sometimes will ,but not always.if I have tried to read the codes with the off/on key diagnostics but all that happens is the check engine light flashes very fast or not at all, battery is new and have replaced computer I don't know where to go from here,

SOURCE: 2004 Jeep Grand Cherokee. Keeps stalling, engine

P0505 means the whole Idle Control system, not only the IAM. Check all related sensors (i.e. crankshaft sensor). Check with a voltmeter direct at the connector of the IAM if you get any signal. Remove the IAM from the TB, connect him, let someone switch your ignition key to ON. The IAM need to drive in/out for a short time to find the right position. Hold the IAM near a hard part, that they cant drive out completely! If IAM works fine, check the fuel pressure, check and clean your TB ( if not done yet). If that doesn't work, come back again please

SOURCE: 99 Jeep Cherokee Sport, 4.0L -won't start

you need to have it connected to an OBD2 machine and watch if you are missing the cam sensor showing RPMs
or if your missing crank sensors RPMs,
it could be a wiring problem or computer if your seeing the RPMs from both sensors,and the last thing i would check is hooking up a fuel gauge to the reed valve and watch what fuel pressure you have while cranking,if the cam sensor is the culprit it will turn the fuel off after the cranking.

SOURCE: 2002 jeep grand cherokee with 4.0 engine will die but restart

p0340 is the cam shaft sensor, this will cause it to cut off while driving, hardtime starting, p0351 is the ignition coil A primary/secondary curcuit mal function. p1391 is ignition system misfire, this could be plugs, wires, or coils. first of all have the cam sensor changed and it may correct the rest of the codes. when fixed turn light off with obd2 scanner. if you do not have one, then any auto parts store will erase the codes fo free of charge.

SOURCE: 1996 Jeep Grand Cherokee - Will Not Start or Run

they have crankshaft sencers on the transmission on jeeps. it would be up high on the drivers side on front of transmission. they will cause it to not get fuel or fire and can run then quit.

SOURCE: rough idle stalls at low rpm's

chk and change complete throttle body with tps and idle motor also chk vaccum leaks