Startin and runnin problems

If you have to remove the PCV to get it to run, it's starving for air. Most likely a bad idle air control valve. Battery wont hold charge is a separate issue. Get your charging system tested

http://ricksfreeautorepairadvice.com/bad-idle-air-control-valve/

When your idling at a stop or parked an the engine is running A/C on cooling fans should be running . When your driving down the road air flow through the condensor is good enough and the fans don't run .

START BY CHECKING ALL THE GROUND CONNECTIONS.CHECK FUEL PRESSURE,KNOCK SENSOR,IDLE AIR CONTROL MODULE,IGNITION COIL OR A POSSIBLE VACUME LEAK!

The only component I know of, that shuts a Jeep off while idling or driving 40mph down the road, is a bad crank sensor. Usually when it starts going bad, it will sporadically shut off, like yours does. Eventually, it will just die and the Jeep will not start at all. Have it tested and replaced, if necessary.

A bad crank sensor will shut the jeep off suddenly, while driving down the road, then restart later and it repeats over and over until you replace it.

Run a fault code test as a starting point for diagnosis of this problem, learn how to do that here

Hi, i have a 1999 jeep grand cherokee, 4.0 litre, had the same problem, quits running out of the blue, driving down the road, or sitting idling. starts right back up or takes some cranking to get it running. found out that the crankshaft position sensor was going bad, cost 40$ for the part, but had to have mechinac replace it due to it's location, hard to get at. jeep runs great now.

P1294 indicates a vacuum problem or a idle motor control problem. Since you already checked for vacuum leak then the iac on the side of the throttle body will need to be removed and cleaned. The best thing to do is remove the whole throttle body so it can be cleaned as well - both with carb cleaner. The idle solenoid (motor) on side of throttle body should be removed to do a through cleaning. All of the black needs to be removed from inside both before remounting to the intake. Make sure all connections and bolts are tight before starting engine.

At idling speed an engine does build up a lot of heat and the cooling fan will kick in. In slow moving traffic or traffic jams the temperature gauge can touch the red - particularly on hot days. The reason it cools down when you start moving is because of the air flow through the radiator.

Presumably there are no leaks from the cooling system otherwise you would have mentioned it. In normal circumstances the fan will not be running as you are driving at speed, as the air-flow through the radiator is sufficient to cool things. The fan only kicks in to get rid of excess heat - and this usually occurs at idling speed or after you have parked the car.

If the fan is running all the time as you drive, this points to either a fault in the fan switch, or the car is running too hot. presumably in normal driving the fan isn't running and the temperature gauge reads normal?

It is common - in stationary traffic many cars overheat (particularly big engined models) try to stall and 'cut out'. Restarting can be difficult until the engine cools down.

Is your car overheating in normal driving conditions or just at idle speed? Overheating in normal driving conditions can be caused by things like a failing water pump, blocked radiator, collapsed hose, faulty thermostat or, in the worst case scenario, cylinder head problems.

Overheating at idling speed is 'common'. Check your coolant level. If your car isn't using/losing coolant then there probably is no major problem. You can flush out the cooling system and refill with new coolant - and also check your radiator. Are the cooling fins crumbling with age? Or maybe they're partly clogged with insects and debris from the road? A blast with a hosepipe wil sort that out ..

The question is how much does your car overheat in normal driving? If it doesn't .. it appears as though you have nothing to worry about as such. Most cars have 2 speed fans... the 2nd faster stage kicks in at some point dependant on engine temperature. Perfectly normal.

either low coolant or your IAC motor is acting up