Wednesday, May 1, 2013

jeep Grand Cherokee turns over but no start

Jeep Grand Cherokee will not start


Turns over but no start problem on 99 jeep grand Cherokee limited 4.7


Troubleshooting No start problem:

1) Take Test light and voltmeter.


  • Unplug one of the coils or fuel injectors and find the dark green/orange wire. This is for the ASD relay.


  • Ground the black lead of your voltmeter and set it to 20v DC. Use the red lead to probe the dark green/orange wire in the connector.


  • This wire should power up for about a second when the key is first turned on and then it should stay powered up constantly when cranking. Check both situations and let me know what you see.
Result: When i put the key forward on the on position is 10.90 and when i start it up is 10.82.



2) Did you check for spark on just one cylinder or did you check at least a couple cylinders? Did you check by inserting a spark plug or spark tester in the end of the coil, grounding the test or plug and cranking the engine over?

Result: removed the 2 front coils one from each side,and no spark.


No Spark On Jeep Cherokee

For this case first check for any codes set.


  • If there is still nothing set then disconnect the cam sensor. The cam sensor is mounted on the side of the right bank cylinder head just forward of the exhaust manifold. It's held in with a single bolt and has a three wire electrical connector.

i suggest to disconnect the cam sensor, crank the engine for ten seconds and see if it sets a P0340.

  • There are multiple possibilities for this problem. If there are no codes setting on their own then that makes it tougher to diagnose since anything that causes a loss of spark should set a code. If you can get a code reader or scan tool on it and do this simple test that would be great.

Please Note you have to unplug cam sensor and not crank sensor.


The crank sensor is the sensor in the right rear of the block by the starter. The sensor we want to unplug is the cam sensor, which is on the right cylinder head just forward of the exhaust manifold. 

About camsensor i would like to say: You can feel it from the top but not see it, but you should be able to see it (but probably can't reach it) if you look up from the bottom.

See cam sensor shown below in the diagram:

camshaft sensor

Location of Jeep Grand Cherokee cam sensor. It's on the right side of the right cylinder head just forward of the exhaust manifold. If you face the engine from the front find the oil fill housing and then move your hand around the side of the cylinder head from there. Before you get to the exhaust manifold you'll find the cam sensor.

Result: I got error P0340.

NOW disconnect crank sensor and see what code you get:


Let's disconnect the crank sensor now too along with the cam sensor. Crank the engine again and see if it sets a P0320 also.

If so, then we'll clear the codes, plug the cam sensor back in, crank it and see if it sets just a P0320. 

WHY TESTING THE ERROR CODE IS NECESSARY?

The reason for unplugging the crank sensor and seeing if it sets a code is because we don't really have the equipment to see if the sensors are producing a signal. 

Problem noticed is Loss Of Spark:

Nothing should cause a loss of spark without setting a code. I think what may be happening is the cam sensor is causing the crank sensor to not produce a signal.


Understanding Cam Sensor And Crank Sensor:

The cam and crank sensors share a sensor ground and a 5v reference voltage, the third wire at each sensor is the signal wire and goes to the PCM. What sometimes happens is the cam sensor will short internally and take down the crank sensor's 5v reference. When this happens the PCM doesn't know the engine is turning, so there will be no codes yet no spark.

Reason For Unplugging the Crank sensor:

By unplugging the crank sensor and cranking the engine with the cam sensor plugged in that would allow us to see if it will set a crank sensor code or not. If it didn't set a code with it unplugged then we know the cam sensor is causing the issue.

Simple Solution Without Testing:

The alternative is to try replacing the cam sensor and see if that takes care of it. As per description it seems faulty cam sensor

If you don't want to get back to the crank sensor and unplug it then as a next step I'd recommend replacing the cam sensor. If you do I'd recommend a Mopar sensor as aftermarkets are known to cause problems even when new. Mopar parts are of very high quality and good performing parts.

Understand the Location of Sensor And Filter Parts:

The oil sender is on the left side of the front of the engine right next to the oil filter.

The cam sensor is on the right side of the right cylinder head just forward of the exhaust manifold. Find the oil filler neck and slide your hand around the right side of the head toward the manifold and you'll find the cam sensor. See picture of it's location mentioned above, the picture is the right side of the engine and cylinder head as viewed from the right front fender area. 

The air filter box is on the left side of the engine compartment so removing it won't help. You can try removing the battery from the right side if you want and that will give you a little better access to the area.

This details will help.
Thanks.

ALSO VIEW THIS RELATED:

For Car parts and diagrams:

CAR MANUAL GUIDE
                 
FOR FREE MANUALS AND GUIDES: ---
Car repair guide?


For all types of car repair help:



Car Backfires

For car repair How to guides:


OVERHEATING: Radiator Fan Not Working

Engine Cooling Fan not Working


"Radiator fan"  "Engine Fan"  "COOLING FAN WILL NOT TURN OFF"

LIFT GATE / TAIL GATE ISSUES

TRUNK WILL NOT OPEN


CAR ALARM ISSUES


Car starter removal, Starter motor testing, Starter repairs, Starter solenoid, Starter wiring,


DOOR PANEL REMOVAL, car door panel, door panel components, front door panel, rear door panel,


HEATER CORE REPLACEMENT, HEATER CORE REMOVAL, TROUBLESHOOT HEATER CORE, FLUSH HEATER CORE,

CAR POWER SEAT, ELECTRIC SEAT, POWER SEAT WILL NOT WORK, SEAT WILL NOT GO FORWARD,



For all types of---------

Timing belt routing diagrams for cars and trucks?



                          

==========

For all types of --------

Drive belt routing diagrams for cars and trucks?




stalling issues:
Engine stalls, car stalls while starting, vehicle stalls while starting, Engine stalls and dies, Car stalls and stops,


CRUISE CONTROL Not working, cruise control replacing, troubleshooting cruise control problems,


TRANSMISSION PROBLEMS:

NO REVERSE ON TRANSMISSION

GEAR SHIFT ISSUES

Transmission fluid leak, transmission gears slip,


TRANSMISSION REPLACING AND TROUBLESHOOTING, INSPECTING TRANSMISSION COMPONENTS, TRANSMISSION FAILURES, OD WARNING LIGHT,


TRANSMISSION FLUID FILLING, WHERE TO FILL TRANSMISSION FLUID, AUTOMATIC TRANSMISSION FLUID, NO TRANSMISSION DIPSTICK,


WINDSHIELD WIPERS, WINDSHIELD WIPERS NOT WORKING,WIPER MOTOR MAKING NOISE,NO WIPERS,WIPER FLUID LEAKS,WIPER FUSE AND RELAY,


COOLANT LEAK ISSUES, COOLANT LEAK PROBLEMS, COOLANT SENSOR, LOW COOLANT,


BRAKE LIGHTS NOT WORKING, REPAIRING BRAKE LIGHTS, NO BRAKE LIGHTS,


CHECK ENGINE LIGHT,ENGINE WARNING LIGHT FLASHING,ENGINE LIGHT ON DASH,DASHBOARD WARNING LIGHT,ECM ERROR CODES,


DASHBOARD WARNING LIGHTS ARE ON, ENGINE LIGHT ON DASH,WARNING LIGHTS STEADY ON DASH,RESET DASH BOARD WARNING INDICATOR,


KEYFOB PROGRAMMING, REPROGRAMMING CAR KEY, KEYLESS ENTRY RESET,ANTITHEFT WILL NOT LET CAR TO START, ANTI THEFT ISSUES, KEYFOB NOT WORKING, KEYLESS ENTRY QUIT WORKING,


IGNITION KEY WILL NOT RELEASE, IGNITION KEY STUCK UP, KEY WILL NOT COME OUT OF IGNITION, FAULTY IGNITION KEY LOCK CYLINDER, REPLACING IGNITION CYLINDER,


HEATER ISSUES:

HEATER NOT BLOWING COLD,NO HOT AIR FROM HEATER,A/C BLOWS HOT AIR,A/C NOT BLOWING COLD, COLD AIR FROM HEATER,BLEND DOOR ACUTATOR CLOSED,HVAC UNIT NOT OPERATING,



HEATER NOT BLOWING COLD,NO HOT AIR FROM HEATER,A/C BLOWS HOT AIR,A/C NOT BLOWING COLD, COLD AIR FROM HEATER,BLEND DOOR ACUTATOR CLOSED,HVAC UNIT NOT OPERATING,



STEERING ISSUES:

POWER STEERING TROUBLESHOOTING, STEERING SQUEAKS, POWER STEERING FLUID LEAKS, FAULTY POWER STEERING PUMP, POWER STEERING NOT WORKING, POWER STEERING BELT,



VEHICLE STARTING ISSUE:

CAR NO START: ENGINE NOT TURNING OVER:

max