I was in stop-and-go traffic and the Jeep engine simply turned off. I shifted the gear into Park and turned the key a few times. The alternator would rotate, however, the engine would not start. I waited for 15 seconds and turned the key and this time the engine started. Otherwise, the Jeep runs great. Any insights? Should I take the Jeep to the dealer? The Jeep has about 8000 miles on it. Thank you in advance.
I was in stop-and-go traffic and the Jeep engine simply turned off. I shifted the gear into Park and turned the key a few times. The alternator would rotate, however, the engine would not start. I waited for 15 seconds and turned the key and this time the engine started. Otherwise, the Jeep runs great. Any insights? Should I take the Jeep to the dealer? The Jeep has about 8000 miles on it. Thank yo
What engine does it have? would the engine crank over? If the engine cranked over it could be a fuel pump problem. If the engine was just dead and would not crank it might be you Crank Position Sensor. when the sensor goes it causes some strange things to happen anything from just dying (which it will do) to starting right up again to not starting for a couple minutes.
Snow...
The Engine is 4.0L Power Tech I-6. Transmission 4 speed Automatic 42RE.
Select-Trac Full time 4WD system. Also, the optional Quadra-Trac II On Demand 4WD System.
V6 195 HP (I believe)
"> The Engine is 4.0L Power Tech I-6. Transmission 4 speed Automatic 42RE.
Uhmm just so ya know when your talking about your jeep, the 4.0 is a straight 6 not a V6. no biggy but it does make a difference.
Snow...
My mistake the engine is a I-6 not a V6.
The Engine does not crank at all, though the alternator is rotating. Is the Crank Position Sensor a mechanical or electrical device? What do you mean by "which it will do"?
Snow wrote:
starting for
advance.
I think that the words you are using for parts don't exactly match up with the words we know them by.
Cranking: The engine moves in a way that simulates running, but is being driven by an electric starter motor attached to the back of the engine. All major assemblies are in motion. When you turn the key to "Start" is should "crank" or "turn over".
Alternator: An electrical part, about the size of a can of nuts, located on the front of the engine, driven by a belt from the crankshaft. It produces electricity. Alternators cannot motor by themselves. If the engine is not turning the alternator cannot be turning.
Crank Position Sensor: A small electronic part located at the back of the engine, it senses when a particular spot on the flywheel rotates past it. The CPS tells the engine computer where in the rotation cycle the engine is and how fast it is running. If the CPS dies the computer thinks that the engine is not running and will not deliver spark or fuel.
Mike's "which it will do" means that CPS failure is a well-known problem for some Jeeps.
If you've got only 8000 miles on the Jeep and it is stalling in traffic you should take it to the dealer. It is still new. Make it their problem.
Translation issues, we mean turn over when we say 'crank' and for sure if the alternator up top is turning, the starter down below is 'cranking' the engine over.
It is not 'firing' when cranking sounds more like it.
If under warranty, I would take it back with suspected CPS issues. It is an electronic part located at 10:00 on the bell housing looking from the back.
The plug for it gets dirty and causes stalls. The plug is just above the exhaust manifold on the back driver's side.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT'suniskae wrote:
I incorrectly thought the alternator and the starter motor are the same (Incorrect assumption: The alternator is normally a generator but acts as a motor when the engine starts hence the name alternator). But after reading your post I checked up the web and now I know: the alternator is not the same as the starter motor. I meant the starter motor in my original message.
When I had the problem, it seemed to me when I turn the key, the starter motor is running but the engine is not turning (I did not feel any shuddering when the engine kicks in). I got the feeling that the starter motor somehow did not couple with the engine. Or maybe the engine was turning but there was no spark or fuel.
I am scared that the engine might stop in the middle of a busy highway. The dealer is likely to find "no problem". I should go the dealer anyway...
Based on it being the 4.0L engine, it could be the crankshaft position sensor. This is a small $70 or so sensor that picks up pulses off the flywheel, which provides the master timing signal for the entire engine. They are known to fail, enough so that I carry a spare... even though mine hasn't failed in 144K miles. While it's not difficult to change, it is a bit of a job for a contortionist since it is up high on the driver's side of the bell housing. A check of your diagnostic codes by turning the ignition key on-off-on three times within five seconds and leaving the key on will cause any stored diagnostic codes to appear in your odometer in 3-5 seconds (wait for them).
If you see a 320, 1391, or a 1398 code, that definitely indicates the CPS (or possibly the camshaft position sensor) has had recent problems.
Jerry
uniskae wrote:
Leave the key in the ON position for 5 seconds, then turn the key. This will allow the fuel system to pressurize.
If if doesn't start, try pressing down on the gas pedal while cranking the engine. If you can't get it started, bring it to the dealership.
When you turn the igntition to start did it crank the motor? Did the starter engage the motor or did it just spin? As in, did the engine make it's usual 'chug, chug' cranking noise or was it a much different and higher pitched spinning noise? If it cranked but didn't fire it'd most likely be the CPS or a fuel problem. But if it just sat there and spun the starter motor then it'd be the start solenoid or its relay.
There's a BIG difference between cranking the engine over and just spinning the starter. They're nothing like each other and not something easily confused. So which actually happened?
Since it's new you should of course make the dealer fix it.
Thank you for showing me how to get fault codes L.W. Hughes III. I got two fault codes:
P1489 (M) High Speed Fan CTRL Relay Circuit An open or shorted condition detected in the control circuit of the high-speed radiator fan control relay.
P1490 (M) Low Speed Fan CTRL Relay Circuit An open or shorted condition detected in control circuit of the low-speed radiator fan control relay.
I do not believe the large radiator fan is running, jsut after starting the engine or after driving 20 miles.
Could this be the cause of engine stall?
L=2EW. Hughes III (=DFill) wrote:
advance.
to check the fan, rig up some test wires and run the fan directly to the battery, if the fan runs then its the relay for the fan. I'm not sure the GC has the ability to shut the engine off if it reaches a over heating condition, generally most vehicles don't. Could just have been that the engine temp. was high enough and when you applied the gas to move it stalled, I've had this happen with my car on occasion. What was the temp. gauge showing when the engine died? if it was in the normal range I would still be guessing a CPS, many times if its intermittent the CPS fault code wont be captured by the computer ,that was the case with mine when the CPS was intermittent. The dealer change the CPS on speculation as the fuel pump was working fine and everything else checked out ok.
Snow...
P1489 (M) High Speed Fan CTRL Relay Circuit An open or shorted condition detected in the control circuit of the high-speed radiator fan control relay.
P1490 (M) Low Speed Fan CTRL Relay Circuit An open or shorted condition detected in control circuit of the low-speed radiator fan control relay.
I do not believe the large radiator fan is running, jsut after starting the engine or after driving 20 miles.
Could this be the cause of engine stall?
L.W. Hughes III (ßill) wrote:
advance.
Engines can stall when too hot. This is not a good thing.....
I would be getting that into the dealer fast before you kill the engine. Overheating or running hot will fast cook the valve seals and turn the engine into a smoker, let along kill head gaskets, etc....
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT'suniskae wrote:
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