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Bad Camshaft Positioning Sensor???

40K views 21 replies 7 participants last post by  Jim_Lou 
#1 ·
Well Rode the motorcycle all the way from seattle washington to charleston SC. Now it's time to get the jeep running again so i can enjoy it in the sun. ok, once again this thing turns over but wont start. battery has a good charge. fuel it getting the injectors, I checked the codes and it threw me a code of "12" which of course just measn that the battery has been disconnected over the past 50 start-ups. It also threw code "54" which means that the camshaft positioning sensor is bad or faulty. I am planning on replacing it tomorrow and hoping that it will that and not the computer. Would a bad Camshaft positioning sensor keep the jeep from cranking up? would it caus ethe symptoms I had while driving it about 6 months ago? these symptoms are driving 30 miles or so then stumbling and then having to wait about 15 minutes to drive again? How hard is it to replace a camshaft positioning sensor on a 97 TJ sport? where is it located and do I need any special tools to remove it? Looked in the haynes manual and it didnt say hopw to remove it. Thanks for the help guys, have a good night.
 
#2 ·
If it threw the code for the cps I would replace it. It could cause your symptoms. Also look for a chaffed or burnt wire. CPS is probably the easiest item under the hood of a jeep to replace. unscrew, disconnect and reverse process. Simple and easy. I have heard of mud packed inside the flywheel causing issues, but that is tough for me to believe...
 
#3 ·
you are talking about the CAMSHAFT POSITIONING SENSOR and not the CRANKSHAFT POSTIONING SENSOR right?
 
#4 ·
The Camshaft Postioning Sensor can do some odd things when it starts to fail. It's also called the Distributor Stator Assembly and sometimes the pick-up plate.

The camshaft position sensor is located under the distributor cap and you don't need to remove the distributor to remove/replace it.



The Camshaft Position Sensor can cause the problem you're seeing, however the CPS (Crankshaft Position Sensor, aka: TopDeadCenter sensor) can also show the same symptoms.

These sensor work hand in hand to time the engine. If you get a Code 11, the problem usually is the CPS sensor, and then the I'd look at the camshaft position sensor.

However since you're getting a hard set Code 54, the camshaft position sensor is the starting point. But before I'd start throwing parts at the Jeep, and this part is not cheap, try looking at
  • the connector pins. They could be tarnished, or loose. Look at the mating connector as well, and
  • the wiring. The wire could be breaking under the insulation. You'll need an Ohm Meeter to test this... and places like Harbor Freight has a Cen-Tech DMM on sale for $3. I keep one in every car and three more in each varied tool kits. Flex the wires to see if the symptoms change.

Just be prepared to replace the CPS sensor. As I said all these sensors work hand in hand, together. The Computer can be fooled into thinking the Camshaft sensor is bad when it's really the Crankshaft sensor causing the problems. It depends on when the signal is lost. In cases like this, the only way you'll really know, is by replacing the sensors.
 
#6 ·
well, i replaced both the Crankshaft and Cam shaft sensors and I still got nothing fromthe jeep. It just turns over. I am gonan check for spark next but if that isnt it then I think it is the computer. What else could it be after that? Z50k2 ( Ricky ) can you PM me your phone number so I can have you plug in the new computer for me and see if this thing cranks up? thanks for the help guys.
 
#8 ·
Just went out and checked the fuel rail, plenty of fuel comming out. checked for spark and there is no spark at all. would the computer cause it to have no spark, or is it the coil or the distibutor or somthing.
 
#9 ·
CPS generates a pulse.

The pulse is seen by the computer, or it fires an 11 code.

The computer applies voltage to engage the AntiShutDown (ASD) relay.

The ASD realy feeds voltage to the ignition system and the fuel system

If you've got fuel OR spark, the ASD relay is working

Now look at the reason you don't have spart.

Did you have spark before?

Did things change when you installed a sensor.

If so, reinstall the old sensor. and see if things change back.
 
#10 ·
ok i am gonna start from the begining (this is a long story)! I went wheeling down here in summerville. The next week is was leaving for the long drive back to the Seattle area so I took the vehical to a frriend of mine who is a mechanic. he looked under the hood and told me that i would be wise ot remove most of the mud off the engine. So being the stupid 21 year old I am i sprayed down the engine with the hose and i didnt cover any of my electrical stuff under the hood. stupid thing to do I know. things ran great for about two days then the day before we left i noticed that the idle was really high on the jeep. Then the jeep threw a code for a Tps. I then replaced that! the jeep ran great after that. We hit the road. got to atlanta georgia and while going highway speeds ( 70 mph ) the jeep would stumble like it wasnt getting any fuel or no spark. we would then pull over and let the jeep sit for about 15 or 20 minutes and then start her up and keep going. Another 25 to 30 miles and it would stumble again. I then replaced the MAP sensor and the Cam shaft positioning sensor. problem of stumblig still persisted. got the jeep town to agusta goergia, we let it sit over night. got in the next morning and it drove normally all the way back to Charleston, which is a 110 miles drive or so. Not a single problem. I flew back to seattle. The jeep has been sitting of rabout five and half months. It was periodically started up by my grand father who just let it idle. it quit on him about two months ago. now it just turns over and wont start. I have replaced the Camshaft positioning sensor, the Crankshaft positioning sensor, The map sensor, the TPS, anf the jeep is getting plenty of fuel. Once again when the jeep was stubleimg before on the highway it only did it on the highway, never did it when idling or while driving city speeds, only did it at 60 to 70 mph. I think i need to replace the computer or atleast plug in a new one and see if it starts.
 
#11 ·
Keep in mind that the apearance of fuel coming out of the rail does not endure that the pressure is high enough for the system. I think when you posted this before I told you how I chased the same problem for months only to find I had a bad fuel pump. My pressure would read correct at Idle up to 3000 rpm where the pressure took a nose dive. I still put my money on the pump, but don't just throw one in, get a cheapie fuel pressure guage and connect it see what the actual pressure is.
 
#12 ·
I still dont have any spark, The fuel pump is a good idea but the spark problem is what i am worried about.
 
#14 ·
I pulled one of the spark plugs, grounded it out on the chasis and turned it over. My uncle watched it and said there was nothing, no spark at all. The coil is brand new, the wires, spark plugs, cap and rotor are only a year and half old. Ill have the coil tested at auto zone and see what they say, but other than that I just want to plug in a new Computer. I am giving myself one more week to figure this thing out and if it doesnt work i am taking it to a mechanic.
 
#15 ·
Food for thought....

Ryan, if you're correct about the ECM, there's one thing to consider.... If the ECM went bad, there's a reason it did. Untill you know that reason it is unwise to just plug in another one. You may damage the second ECM simply by plugging and chugging.
 
#16 ·
Sounds to me like a corroded connector problem.
Throwing parts at it arbitrarily seldom works and is frustrating.

Take loose all the connectors one at a time and clean the contacts with a GOOD contact cleaner. Concentrate on the connections at and under the relay box and the connections to the ignition system.
And take the distributor cap off and blow it out inside. Water can get under everything where you can't see it, on the road it vaporizes and shorts out the cap.
 
#17 ·
Well boys I got her fixed, She is running as good as the day I left her here in Charleston. You guys are gonna think I am the biggest IDIOT in the world but I guess that the CAMSHAFT POSITIONING SENSOR was bad after all. when I put the new one on I forgot to reconnect the wire togther. I went out there and happen to find that I had forgot to connect them. put them togther and It started right up. It was idling really rough. tried to drive it around the block and it seemed like it was misfiring a cylinder. so I brought it back and and swaped two of the wires around that I had been playing with yesterday and I guess I must have put them on backwards because it ran so much smoother and idled so much better after swaping them. I am glad I dont need a new ECU that saved me a bunch of money. I am gonna give the jeep a full tune up tomorrow and get her back on the road. I greatly appreciate all the help you guys gave me. Thanks RYAN
 
#19 ·
Glad you got it running....

Tune up? Nothing to really 'tune up'. Check the fluids, make sure the filters are clean, bolts are tight, wires connected and not laying on a hot exhaust....and thats about it. There is nothing to adjust like in the 'old days'.....
 
#20 ·
Well, I went ahead and did an oil anf filter change, New wires, Plugs, Cap, Rotor, New front pads and Rotors. This jeep is running so much better sinc ei Put the Champion Platinum plugs in it. It's been about a year and a half since It had a good tune up. TIME TO GO WHEELING, HE HE HE!
 
#21 ·
Same problem here !

Ryan how did you get your problem resolved ?
I am having the same problem for 3 months now.

Any advice appreciated !

Well here is my issue:
Well here's the issue:
1990 2WD 4.0 6cyl miles: 125000 starts up on the 3rd crank when cold.
It runs for a while and then dies.

After it dies there is No spark and it will not start
until the next day- then it will start and do the same thing.

history:
Problem got gradually worse with hard warm start earlier this year and
then die offs after 15 miles gradually getting shorter now it might die anytime.

Parts replaced:
cap, cables, plugs, airfilter, gas pumps ( 2nd within 800 miles although I think it has nothing to do with the problem), gas filter, CPS, starter, battery,
seafoamed throttle, MAP sensor vacuum hose checked.
jumped the ballast resistor ( which get's quite hot ).
 
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