Camshaft position sensor

Hi all, new to the forum here. Hate to start off with a problem but I could really use some help on this.
I have a 2001 Grand Cherokee Laredo w/ the 4.0.
The first time you try to start it, it wont start, turn it off, crank it again and it starts right away. Let it sit awhile and you get the same thing.
I can crank it for 30 seconds the first time and nothing, turn the key off, crank it again and she starts, or I can crank it for 2 seconds, turn it off, crank it again and she runs. It also runs just perfect, just wont start the first time you try and start it.

I did the key on off on off on thing and got code : P0340 (M)

Camshaft Position Sensor A Circuit (Bank 1 or Single Sensor)

A rationality error has been detected for loss of camshaft position sensor (no fuel sync).

Now for the questions, does this mean the camshaft position sensor needs to be replaced, if not what does it mean? Is this even the problem with the starting? Is it located where the distributor usually is? And finally do you just simply replace the old one?

Thanks
Jeff

Oh, I forgot to add that I don't think it's a fuel pressure problem because......now bear with me, but this seems logical, if it were a fuel pressure problem wouldn't cranking it 10 to 20 seconds prime or pressure up the system?
I can crank it 2 seconds the first time and it starts up on the second time. I can crank it 20 seconds the first time and it won't start, but turn it off, hit it again and presto!

Hi all, new to the forum here. Hate to start off with a problem but I could really use some help on this.
I have a 2001 Grand Cherokee Laredo w/ the 4.0.
The first time you try to start it, it wont start, turn it off, crank it again and it starts right away. Let it sit awhile and you get the same thing.
I can crank it for 30 seconds the first time and nothing, turn the key off, crank it again and she starts, or I can crank it for 2 seconds, turn it off, crank it again and she runs. It also runs just perfect, just wont start the first time you try and start it.

I did the key on off on off on thing and got code : P0340 (M)

Camshaft Position Sensor A Circuit (Bank 1 or Single Sensor)

A rationality error has been detected for loss of camshaft position sensor (no fuel sync).

Now for the questions, does this mean the camshaft position sensor needs to be replaced, if not what does it mean? Is this even the problem with the starting? Is it located where the distributor usually is? And finally do you just simply replace the old one?

Thanks
Jeff


HI, IT SOUNDS LIKE YOU MAY HAVE A BAD CRANKSHAFT POSITION SENSOR. USUALLY IF THE CAMSHAFT POSITION SENSOR IS BAD IT WILL CRANK BUT WILL NOT START AT ALL. DOES THE CHECK ENGINE LIGHT COME ON EVERYTIME YOU TURN THE KEY ON? DALE
jeepman600@aol.com questions holler :nono:

The check engine light comes on during the cranking of the motor, but goes off once it starts.

The check engine light comes on during the cranking of the motor, but goes off once it starts.



HI, SOUNDS LIKE THE CRANKSHAFT SENSOR MAYBE BAD LIKE I SAID IF IT WERE THE CAMSHAFT SENSOR IT WOULDN'T START AT ALL. DALE jeepman600@aol.com :nono:

Well, it wasn't the camhaft position sensor, decided to change it because of the code, and it fixed that, but it still won't crank the first time. Guess I'll change the crankshaft sensor next, anybody know where it's located?

Jeff

How much do both sensors cost. im looking to stock up just incase any future probs

OKJEEEPIN send me an email with year and engine size and I will send u instructions on Crank Sensor change.

dksob81@hotmail.com

Joe

The Camshaft sensor was $50 at the dealer, $109 at a parts store, go figure?! I don't know about the Crankshaft sensor for sure but I think it is only $35.

Anyway guys, I have (well really the dealer) solved the starting problem, it WAS the fuel pump! Cost me $436 total for a new one installed at the dealer. Apparently when there is not enough pressure, the motor won't start even if it gets pressure after the first couple times it turns over, then when you turn the key off, and hit it again it tell's the 'puter it has the right pressure and varoooom!
Thanks again for all your help.

Jeff

do u still need those instructions?

You bet, I sent you an email.

Thanks
Jeff

ok I sent them, let me know if u got them, I included the instruction and some pics in an attachment of the email.

Very good info, looks like it might be a little hard to get to, but what isn't anymore. Anyway thanks for the help.

Jeff

yup, keep us informed of any changes.

Well, it wasn't the camhaft position sensor, decided to change it because of the code, and it fixed that, but it still won't crank the first time. Guess I'll change the crankshaft sensor next, anybody know where it's located?

Jeff

I am having th e same problen with my 03 gr. cheerokee. SHoul I just go straight to changing the fuel pump?

You very likely have a pump thats getting weak. I'd get a pressure guage on it and check it before coughing up mega bucks on a hunch.

My 5.9 Durange just had the same issue. It showed up quite obviously on the pressure guage.

You very likely have a pump thats getting weak. I'd get a pressure guage on it and check it before coughing up mega bucks on a hunch.

My 5.9 Durange just had the same issue. It showed up quite obviously on the pressure guage.

I know this may sound silly but, where would I get a pressure gauge or who would check pressure for me? Thanks!

I am having th e same problen with my 03 gr. cheerokee. SHoul I just go straight to changing the fuel pump?

Try turning the key on and waiting 15--30 seconds then try starting, if this works you may have a fuel pump going bad. CHECK BEFORE HAND.
Dale jeepman600@sbcglobal.net :2cents:
Auto- zone has gauges $ 37.98

I know this may sound silly but, where would I get a pressure gauge or who would check pressure for me? Thanks!

Chain auto parts stores usually have an aisle with that kind of stuff. I always have a tough time rationalizing a purchase like that though. It's got to be a tool I'll use often enough to justify the space it takes up in the shed.

First, let me say that you may want to check the 'distrbutor the sensor is sitting on as I am working on one of those right now and the threads on it were chewed up.
I don't know if this makes me sound like a noob to newere cars, though I am, lol, but I am trying to find info on how to time the distributor or whatever it is called on the same model, year and engine as this gentleman.
I know I have to set cyl 1 to topdeadcenter but I am unsure as to how to do that. I typically work on GMs and imports and almost always on models older than 95 so some of this new stuff like the ignition setup is new to me.
If anyone can give me a step by step on timing this engine after replacement of the sensor and distibutor, I'd appreciate it.

If engine crankshaft or camshaft has been rotated, such as during engine tear-down, CMP sensor relationship must be reestablished.

Remove ignition coil rail assembly.

Remove cylinder number 1 spark plug.

Hold a finger over the open spark plug hole. Rotate engine at vibration dampener bolt until compression (pressure) is felt.

Slowly continue to rotate engine. NOTE Do this until timing index mark on vibration damper pulley aligns with top dead center (TDC) mark (0 degree) on timing degree scale. Always rotate engine in Direction of normal rotation. Do NOT rotate engine backward to align timing marks.

Install oil pump drive into engine while aligning into slot on oil pump. If pump drive will not drop down flush to engine block, the oil pump slot is not aligned. Remove oil pump drive and align slot in oil pump to shaft at bottom of drive. Install into engine. Rotate oil pump drive back to its original position and install hold-down clamp and bolt. Finger-tighten the bolt. Do NOT do a final tightening of bolt at this time.

Remove toothpick from housing.

Install sensor to oil pump drive. After installation:, the CMP sensor should face rear of engine: 0.

Install 2 sensor mounting bolts and tighten to 2 Nm (15 inch lbs.) torque. Connect electrical connector to CMP sensor.

If removed, install spark plug and ignition coil rail.

To verify correct rotational position of oil pump drive, the DRB scan tool must be used. CAUTION When performing the following test, the engine will be running. Be careful not to stand in line with the fan blades or fan belt. Do NOT wear loose clothing.

Connect the scan tool to data link connector. The data link connector is located in passenger compartment, below and to left of steering column.

Gain access to SET SYNC screen on the scan tool.

Follow the Directions on the scan tool screen and start engine. Bring to operating temperature (engine must be in closed loop mode).

With engine running at idle speed, the words IN RANGE should appear on the scan tool screen along with 0. This indicates correct position of oil pump drive.

If a plus (+) or a minus (-) is displayed next to degree number, and/or the degree displayed is not zero, loosen, but do NOT remove hold-down clamp bolt. Rotate oil pump drive until IN RANGE appears on screen. Continue to rotate oil pump drive until achieving as close to 0 as possible. NOTE The degree scale on SET SYNC screen of the scan tool is referring to fuel synchronization
only. It is not referring to ignition timing. Because of this, do NOT attempt to adjust ignition timing using this method. Rotating oil pump drive will have no effect on ignition timing. All ignition timing values are controlled by powertrain control module (PCM).

Tighten hold-down clamp bolt to 23 Nm (17 ft. lbs.) torque.


First, let me say that you may want to check the 'distrbutor the sensor is sitting on as I am working on one of those right now and the threads on it were chewed up.
I don't know if this makes me sound like a noob to newere cars, though I am, lol, but I am trying to find info on how to time the distributor or whatever it is called on the same model, year and engine as this gentleman.
I know I have to set cyl 1 to topdeadcenter but I am unsure as to how to do that. I typically work on GMs and imports and almost always on models older than 95 so some of this new stuff like the ignition setup is new to me.
If anyone can give me a step by step on timing this engine after replacement of the sensor and distibutor, I'd appreciate it.