I have an 03 Liberty w/ 60000 miles on it. Recently, the car has been stalling for some reason. It generally cuts out when idleing but has cut out at rmps as high as 2800. I repaced my plugs thinking I wasn't getting good spark on a cylinder but that hasn't help. My check engine light came out the first time it happend signaling cam shaft alignment and misfire code. It started up and ran fine and the light actually tuned off. Now it has happend a couple more times. I'm still on the same tank of gas however. Could this be bad gas? Electronics? Something serious?
Jeep Stalling; Check engine Light on
- Thread starter Prest989
- Start date
Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.
Check engine light came on and my '03 Limited stalled on the highway. Got it started again and home, sat in the driveway and it kept stalling. Only thing noticeably wrong was the check engine light. Will see what the dealership says. Also forgot, this all started happening after the LBJ broke while the wife was driving. Again, we'll see.
Error codes
121
122
1299
All to do with the throttle position sensor and vacuum leak.
Error codes
121
122
1299
All to do with the throttle position sensor and vacuum leak.
thecause17
Full Access Member
Who's thread is this...anyways, I'll go with the original poster.
I'm sure these vehicles have a cam position sensor(s). If that went bad I could see getting both those codes as I would imagine the computer relies on it for timing for each cylinder's spark(or the cranksensor, or a combination of the two, not sure). Out of all the codes, there doesn't seem to be a code for the camshaft sensor other than a "no signal" so if it's giving an erratic signal or something to that nature, it may cause a problem.
Here's the list I found, http://www.jeepkj.com/forums/viewtopic.php?t=325 Which codes do you have off that list? I didn't see anything for "camshaft alignment"
I'm sure these vehicles have a cam position sensor(s). If that went bad I could see getting both those codes as I would imagine the computer relies on it for timing for each cylinder's spark(or the cranksensor, or a combination of the two, not sure). Out of all the codes, there doesn't seem to be a code for the camshaft sensor other than a "no signal" so if it's giving an erratic signal or something to that nature, it may cause a problem.
Here's the list I found, http://www.jeepkj.com/forums/viewtopic.php?t=325 Which codes do you have off that list? I didn't see anything for "camshaft alignment"
thecause17
Full Access Member
Re: Sorry bout that
Yours is probably a TPS since it's coming up in all three codes. It just mentions the MAP sensor because it's comparing TPS values to it, and the vac leak is a possible solution. I doubt it's a vac leak mostly because of the code for low voltage on the TPS...but I'm not a mechanic. ](*,)
campj0le said:
Yours is probably a TPS since it's coming up in all three codes. It just mentions the MAP sensor because it's comparing TPS values to it, and the vac leak is a possible solution. I doubt it's a vac leak mostly because of the code for low voltage on the TPS...but I'm not a mechanic. ](*,)
2003KJ
Member
Re: Sorry bout that
X2. The cam and crank sensors can really play hell with an engine when they go out. Crank sensors will stop an engine dead in its tracks and not allow it to run again, and cam sensors can sometimes to crazy stuff like you are describing....let it run for a few seconds then it stalls again.
I'll X2 this one as well. Somewhere in one of my FSM's theres a procedure to the TPS if i'm not mistaken. I'll look it up in a little bit and see what if I can find it.
thecause17 said:
X2. The cam and crank sensors can really play hell with an engine when they go out. Crank sensors will stop an engine dead in its tracks and not allow it to run again, and cam sensors can sometimes to crazy stuff like you are describing....let it run for a few seconds then it stalls again.
thecause17 said:
I'll X2 this one as well. Somewhere in one of my FSM's theres a procedure to the TPS if i'm not mistaken. I'll look it up in a little bit and see what if I can find it.
indieaz
Full Access Member
Re: Sorry bout that
2003KJ said:
thecause17
Full Access Member
Re: Sorry bout that
indieaz said:
indieaz
Full Access Member
Re: Sorry bout that
Well, a knock sensor is used to detect knock ...which indicates a potential problem with timing or possible fuel mixture problems (evne if timing is dead on but the mixture is too lean that will cause knock). Of course in this scenario the ECU would pull timing to prevent knock like you say.
My problem is i was thinking of my experiencing working on GM LT-1s which aren't truly distribitorless...in that application the crank position sensor has nothing to do with timing and is actualyl used in misfire detection. Of course in a completely distributorless system like on our jeep's the crank sensor is needed to verify the cam is in phase with the crank position for timing.
thecause17 said:
Well, a knock sensor is used to detect knock ...which indicates a potential problem with timing or possible fuel mixture problems (evne if timing is dead on but the mixture is too lean that will cause knock). Of course in this scenario the ECU would pull timing to prevent knock like you say.
My problem is i was thinking of my experiencing working on GM LT-1s which aren't truly distribitorless...in that application the crank position sensor has nothing to do with timing and is actualyl used in misfire detection. Of course in a completely distributorless system like on our jeep's the crank sensor is needed to verify the cam is in phase with the crank position for timing.
thecause17
Full Access Member
Re: Sorry bout that
Exactly, pinging, knock, predetonation, whatever you want to call it. I'm still confused on how a crank position sensor would be used to detect misfires. Unless you mean the computer is comparing distributor/coil firing in relation to which piston should be at the proper position at any given moment when that particular plug fires. I guess if it didn't detect a fire on a cylinder and catches that that cylinder should've fired by looking at the position of the crankshaft to determine that it was in the spot it needed to be in when it was supposed to have ignition. Is that what you mean? I'm not calling BS on you or anything, just trying to figure out what you mean, I'm all about learning. #-o
Here's an example.
The crankshaft is rotating and cylinder #1 rises to it point where ignition is supposed to take place. The distributor doesn't send a fire to spark plug #1(or it does but the spark plug is bad or whatever). The computer catches that a misfire took place by looking at the location of the crankshaft and determines that ignition should've taken place at the point. Is that what you mean?
I guess we're a little off topic...anyways, like I said, not causing trouble, just curious.
indieaz said:
Exactly, pinging, knock, predetonation, whatever you want to call it. I'm still confused on how a crank position sensor would be used to detect misfires. Unless you mean the computer is comparing distributor/coil firing in relation to which piston should be at the proper position at any given moment when that particular plug fires. I guess if it didn't detect a fire on a cylinder and catches that that cylinder should've fired by looking at the position of the crankshaft to determine that it was in the spot it needed to be in when it was supposed to have ignition. Is that what you mean? I'm not calling BS on you or anything, just trying to figure out what you mean, I'm all about learning. #-o
Here's an example.
The crankshaft is rotating and cylinder #1 rises to it point where ignition is supposed to take place. The distributor doesn't send a fire to spark plug #1(or it does but the spark plug is bad or whatever). The computer catches that a misfire took place by looking at the location of the crankshaft and determines that ignition should've taken place at the point. Is that what you mean?
I guess we're a little off topic...anyways, like I said, not causing trouble, just curious.
2003KJ
Member
Prest989 said:
Why can't you replace them?
indieaz
Full Access Member
Re: Sorry bout that
Yes, that's exactly it works. I thinkt he only car that actually works liek that is the GM LT series engines. They used a semi-distributorless ignition system. There was technically a distributor there, but it was computer controllerd. It's hard to explain. It was a system called the optispark - it was driven directly off the crank and had an optical eye to detect distributor/cam position. The PCM then decided based on the timing tables when to send spark in relation to the cam position. So it worked like a distirbutorless idnition - but still had a physical moving wheel in it. From 92-94 there was no cam position sensor - the cam position was the only variable taken into account for timing. In the 95-97 years they added a crank position sensor which was used to compare the timing the PCM sent off spark. When the two didn't match it would actually throw an engine misfire bank 1/2 code. This compared not just cam and crank position - but also when the PCM itself actually decided to send spark to the cylinder. It is sort of a ******** system.
thecause17 said:
Yes, that's exactly it works. I thinkt he only car that actually works liek that is the GM LT series engines. They used a semi-distributorless ignition system. There was technically a distributor there, but it was computer controllerd. It's hard to explain. It was a system called the optispark - it was driven directly off the crank and had an optical eye to detect distributor/cam position. The PCM then decided based on the timing tables when to send spark in relation to the cam position. So it worked like a distirbutorless idnition - but still had a physical moving wheel in it. From 92-94 there was no cam position sensor - the cam position was the only variable taken into account for timing. In the 95-97 years they added a crank position sensor which was used to compare the timing the PCM sent off spark. When the two didn't match it would actually throw an engine misfire bank 1/2 code. This compared not just cam and crank position - but also when the PCM itself actually decided to send spark to the cylinder. It is sort of a ******** system.
thecause17
Full Access Member
Re: Sorry bout that
Sounds like it. My old Probe had a similar sort of set-up also. It had a distributor, but was also computer controlled. You could actually loosen the distributor and turn it while the car was running and it made no difference because the computer would just adjust for the timing, as opposed to a true distributor ignition, the position of the distributor determined the degree of advancement for the timing.
Cool. \
/
indieaz said:
Sounds like it. My old Probe had a similar sort of set-up also. It had a distributor, but was also computer controlled. You could actually loosen the distributor and turn it while the car was running and it made no difference because the computer would just adjust for the timing, as opposed to a true distributor ignition, the position of the distributor determined the degree of advancement for the timing.
Cool. \
/
indieaz
Full Access Member
Re: Sorry bout that
Yah, in this case the "distributor" was actually behind the water pump bolted to the front of the negine (front of timing cover - driven directly off cam). To remove it you had to remove the harmonic balancer and the water pump. Depending ont he year when installed you could misalign the gear that drives it and essentially throw your timing as much as 180* out. A source of frustration for sure (I did it myself once).
Here's a pic of one partially taken apart...if you continued taking it apart there is a metal wheel with about 160 holes and an optical eye with a comptuer chip. http://www.aqtda.org/journal/vol1no4/img/optiSpark/optiAsm.jpg
[/thread hijack]
OP: Changing the crank position sensor and cam sensor are likely easy. I haven't identified their locations ont he 3.7 yet (since i've had no reason to so far) but you will probably find they are each held in by 2-3 small bolts. I know on some engines though the engine has to relearn after the sensors are both swapped...so it's possible the first few miles of driving may be rough. Hopefully someone who has done it on our vehicles before can chime in.[/img]
thecause17 said:Cool. \
Yah, in this case the "distributor" was actually behind the water pump bolted to the front of the negine (front of timing cover - driven directly off cam). To remove it you had to remove the harmonic balancer and the water pump. Depending ont he year when installed you could misalign the gear that drives it and essentially throw your timing as much as 180* out. A source of frustration for sure (I did it myself once).
Here's a pic of one partially taken apart...if you continued taking it apart there is a metal wheel with about 160 holes and an optical eye with a comptuer chip. http://www.aqtda.org/journal/vol1no4/img/optiSpark/optiAsm.jpg
[/thread hijack]
OP: Changing the crank position sensor and cam sensor are likely easy. I haven't identified their locations ont he 3.7 yet (since i've had no reason to so far) but you will probably find they are each held in by 2-3 small bolts. I know on some engines though the engine has to relearn after the sensors are both swapped...so it's possible the first few miles of driving may be rough. Hopefully someone who has done it on our vehicles before can chime in.[/img]
2003KJ
Member
If you are interested in changing them youself, let me know and I can dig up some illustrations and info from my FSM for the 2003.
I guess I could try... but its definitatly the cam shaft sensor, (throwing up codes 340 ( no cam shaft sensor signal), 700 (auto trans computer problem) and 1391 ( sometimes no cam shaft signal). Why would the trans computer be messing up? How would I do it if I were to do it myself?
indieaz
Full Access Member
Not sure how our jeep reports codes - but i don' tthink you can have a cam position sensor intermittent and cam position sensors no signal code at the same tim.e I'm guessing at least one of those is a historic code. The transmission code could also be historical. It may depend on the read you're using.
2003KJ
Member
The "sometimes no signal" code is probably a historic code. Now that it's probably not running, would explain the current no signal code.
As far as the transmission code goes, I wouldn't be to concerned. It probably has something to do with the cam sensor going wack.
Let me get you some instructions on replacing that sensor...
As far as the transmission code goes, I wouldn't be to concerned. It probably has something to do with the cam sensor going wack.
Let me get you some instructions on replacing that sensor...
2003KJ
Member
Interesting....my FSM doesn't mention a Cam sensor at all....only a crank sensor.
Are you sure thats what the codes are?
Are you sure thats what the codes are?
Similar threads
