Car misses and dies, then runs perfect
07-12-2015, 06:05 PM
#1
On The Tree
Thread Starter
Car misses and dies, then runs perfect Yesterday I was sitting at a stop light, my car was running fine, no codes nothing unusual and suddenly it sputtered out and died, for about 5 minutes I could no get the car to start, it would turn over but would not start. After about 5 minutes or so it cranked up and ran perfect still not throwing any codes, and it ran fine for the rest of the day. Today I went out and tried to crank the car and it cranked and ran, but was misfiring very badly and then sputtered out and died again, and once again after about 5 minutes struggling to get it to crank it ran perfect again, but this time it is throwing the code for a cylinder 4 misfire, now I've checked the plugs and wires, and tested the resistance on the fuel injectors and got about 16 ohms on each one, the car only has a catback and lid, any idea what could be wrong?
07-13-2015, 11:36 PM
#3
Sounds like a Crank Shaft Position sensor on its way out......
And NO...they will not throw a code until they are completely failed.....which is one of the idiot lights we still have in these late model cars.
I would change it....takes about 10 minutes. If it fixes it, good. If not....return it for a full refund. Just tell them you never installed it because you found the problem was something else. Clean it real good.....
.
And NO...they will not throw a code until they are completely failed.....which is one of the idiot lights we still have in these late model cars.
I would change it....takes about 10 minutes. If it fixes it, good. If not....return it for a full refund. Just tell them you never installed it because you found the problem was something else. Clean it real good.....
.
07-17-2015, 05:09 PM
#4
On The Tree
Thread Starter
It did it for the first time since my last post today, and this time it was cylinder 1, but it was also showing pending codes for a 2 coil packs and a fuel injecter, I know the coil packs don't go bad on these cars often and if it was that I would think it would be bad all the time, any more suggestions?
07-21-2015, 07:54 PM
#7
peteggl,
Curious....did you read post #3.........
If you suspect a coil pack is the issue.....swap it with another cylinder and then see if the code follows over to that cylinder. If it doesn't........read post #3.
Failing CPS cause all kinds of crazy **** to happen.
.
Curious....did you read post #3.........
If you suspect a coil pack is the issue.....swap it with another cylinder and then see if the code follows over to that cylinder. If it doesn't........read post #3.
Failing CPS cause all kinds of crazy **** to happen.
.
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07-25-2015, 10:39 AM
#8
On The Tree
Thread Starter
Yes I changed the CPS, the car is getting no spark at all now and will not fire up, but will turn over
07-25-2015, 06:07 PM
#11
Try cranking the engine over.....and have a friend grab the entire wiring harness bundle that is coming directly out of the PCM, with both hands, and while you are cranking the engine over move that wiring bundle back and forth and side to side. See if it tries to fire......
If it does then you have a loose of frayed ground wire coming out of the PCM.
Could also be a loose ground wire behind the passengers side head...check those bolts, see if they are tight.
,
If it does then you have a loose of frayed ground wire coming out of the PCM.
Could also be a loose ground wire behind the passengers side head...check those bolts, see if they are tight.
,
07-25-2015, 07:32 PM
#12
On The Tree
Thread Starter
Try cranking the engine over.....and have a friend grab the entire wiring harness bundle that is coming directly out of the PCM, with both hands, and while you are cranking the engine over move that wiring bundle back and forth and side to side. See if it tries to fire......
If it does then you have a loose of frayed ground wire coming out of the PCM.
Could also be a loose ground wire behind the passengers side head...check those bolts, see if they are tight.
,
If it does then you have a loose of frayed ground wire coming out of the PCM.
Could also be a loose ground wire behind the passengers side head...check those bolts, see if they are tight.
,
07-25-2015, 07:56 PM
#14
Crank sensor does spark.
Its time to look at the PCM and/or ground wires.......
I had a problem where the PCM-to-Engine ground wire in that bundle of wires coming out of the PCM frayed apart. The electrical guru guy that came to my house moved that bundle of wires as I turned the engine over and it tried to actually start.
He ripped the bundle open and found that ground wire was frayed. So instead of running a new wire all the way to the rear passenger head, he just spliced in a new wire and bolted it down using one of my valley cover bolts. Started right up......
.
07-25-2015, 08:34 PM
#15
On The Tree
Thread Starter
I believe the cam sensor only dictates fuel pulsing.....could be wrong.
Crank sensor does spark.
Its time to look at the PCM and/or ground wires.......
I had a problem where the PCM-to-Engine ground wire in that bundle of wires coming out of the PCM frayed apart. The electrical guru guy that came to my house moved that bundle of wires as I turned the engine over and it tried to actually start.
He ripped the bundle open and found that ground wire was frayed. So instead of running a new wire all the way to the rear passenger head, he just spliced in a new wire and bolted it down using one of my valley cover bolts. Started right up......
.
Crank sensor does spark.
Its time to look at the PCM and/or ground wires.......
I had a problem where the PCM-to-Engine ground wire in that bundle of wires coming out of the PCM frayed apart. The electrical guru guy that came to my house moved that bundle of wires as I turned the engine over and it tried to actually start.
He ripped the bundle open and found that ground wire was frayed. So instead of running a new wire all the way to the rear passenger head, he just spliced in a new wire and bolted it down using one of my valley cover bolts. Started right up......
.
Just tried wiggling the pcm wiring harness around and still got nothing, although I am now throwing a code for coils A-H primary/secondary circuit
07-26-2015, 05:05 PM
#17
If you have no spark and no injector pulse that points to the crank sensor and/or wiring, IMO
Is your tach still showing RPMS when you crank it?
Have you checked for codes since it won't start at all?
Does the car have headers? If so check the wiring harness that goes down the the crank sensor. I've seen several times that wiring harness gets cooked from the headers.
Also if you haven't, check all your fuses.
What type of scanner/code reader do you have and does it show any live data?
Is your tach still showing RPMS when you crank it?
Have you checked for codes since it won't start at all?
Does the car have headers? If so check the wiring harness that goes down the the crank sensor. I've seen several times that wiring harness gets cooked from the headers.
Also if you haven't, check all your fuses.
What type of scanner/code reader do you have and does it show any live data?
07-26-2015, 05:09 PM
#18
From the General,
The Crankshaft Position (CKP) sensor is located in the right rear of the engine, behind the starter. The CKP sensor is a dual magneto resistive type sensor. This sensor is not speed dependent. The dual micro switches monitor both notches of the reluctor wheel for greater accuracy. The CKP sensor works in conjunction with a 24X reluctor wheel. The reluctor wheel is mounted on the rear of the crankshaft. The 24X reluctor wheel uses two different width notches that are 15 degrees apart. This Pulse Width Encoded pattern allows cylinder position identification within 90 degrees of crankshaft rotation. In some cases, cylinder identification can be located in 45 degrees of crankshaft rotation. This reluctor wheel also has dual track notches that are 180 degrees out of phase. The dual track design allows for quicker starts and accuracy.
The PCM also receives a 4X signal from the Crankshaft Position sensor. The PCM utilizes the 4X signal for the following:
Misfire
Tachometer output
Spark control
Fuel control
Certain diagnostics
Observe that as long as the PCM receives the Crankshaft Position sensor 24X signal, the engine will start. The PCM can determine top dead center for all cylinders by using the Crankshaft Position sensor 24X signal alone. The Camshaft Position sensor 1X signal is used by the PCM to determine if the cylinder at top dead center is on the firing stroke, or the exhaust stroke. The system attempts synchronization and looks for an increase in engine speed indicating the engine started. If the PCM does not detect an increase in engine speed, the PCM assumes it incorrectly synchronized to the exhaust stroke and re-synchronizes to the opposite cam position. A slightly longer cranking time may be a symptom of this condition.
The Camshaft Position (CMP) sensor is mounted through the top of the engine block at the rear of the valley cover. The CMP sensor works in conjunction with a 1X reluctor wheel on the camshaft. The CMP sensor is used to determine whether a cylinder is on the firing or the exhaust stroke. As the camshaft rotates, the reluctor wheel interrupts a magnetic field produced by a magnet within the sensor. The CMP sensor internal circuitry detects this and produces a signal which is used by the PCM. The PCM uses this signal in combination with the CKP 24X signal to determine crankshaft position and stroke.
The Crankshaft Position (CKP) sensor is located in the right rear of the engine, behind the starter. The CKP sensor is a dual magneto resistive type sensor. This sensor is not speed dependent. The dual micro switches monitor both notches of the reluctor wheel for greater accuracy. The CKP sensor works in conjunction with a 24X reluctor wheel. The reluctor wheel is mounted on the rear of the crankshaft. The 24X reluctor wheel uses two different width notches that are 15 degrees apart. This Pulse Width Encoded pattern allows cylinder position identification within 90 degrees of crankshaft rotation. In some cases, cylinder identification can be located in 45 degrees of crankshaft rotation. This reluctor wheel also has dual track notches that are 180 degrees out of phase. The dual track design allows for quicker starts and accuracy.
The PCM also receives a 4X signal from the Crankshaft Position sensor. The PCM utilizes the 4X signal for the following:
Misfire
Tachometer output
Spark control
Fuel control
Certain diagnostics
Observe that as long as the PCM receives the Crankshaft Position sensor 24X signal, the engine will start. The PCM can determine top dead center for all cylinders by using the Crankshaft Position sensor 24X signal alone. The Camshaft Position sensor 1X signal is used by the PCM to determine if the cylinder at top dead center is on the firing stroke, or the exhaust stroke. The system attempts synchronization and looks for an increase in engine speed indicating the engine started. If the PCM does not detect an increase in engine speed, the PCM assumes it incorrectly synchronized to the exhaust stroke and re-synchronizes to the opposite cam position. A slightly longer cranking time may be a symptom of this condition.
The Camshaft Position (CMP) sensor is mounted through the top of the engine block at the rear of the valley cover. The CMP sensor works in conjunction with a 1X reluctor wheel on the camshaft. The CMP sensor is used to determine whether a cylinder is on the firing or the exhaust stroke. As the camshaft rotates, the reluctor wheel interrupts a magnetic field produced by a magnet within the sensor. The CMP sensor internal circuitry detects this and produces a signal which is used by the PCM. The PCM uses this signal in combination with the CKP 24X signal to determine crankshaft position and stroke.
07-26-2015, 05:27 PM
#19
If you scanner/code reader shows engine RPM, check it when you are cranking the engine. If it shows 0 the PCM isn't going to command the engine to start.
Some other things to check,
The CKP gets it power from the PCM from pin 2 on the blue PCM connector. You can check it at the PCM for power but that doesn't tell you if you are getting power to CKP.
Pin 12 on the blue PCM connector is the CKP signal input to the PCM. What you can do is use a multi meter and connect it on pin 2 and 12 and crank the engine over. This checks the power, ground and input to the PCM. The CKP uses a 12v square wave pattern to tell the PCM where it's at. Using a multi meter will only show you the average voltage.
INJ1/INJ2 are the fuses for the injectors. If the fuses are good verify you have power at the injectors. The pink wire is the 12v ignition power source. If you have power there then you know the PCM is not commanding the injectors to fire.
If you don't have power at the injectors then it's a wiring issue but the chances of two separate circuits being open or shorted to ground are pretty slim. Especially because you have no spark.
Some other things to check,
The CKP gets it power from the PCM from pin 2 on the blue PCM connector. You can check it at the PCM for power but that doesn't tell you if you are getting power to CKP.
Pin 12 on the blue PCM connector is the CKP signal input to the PCM. What you can do is use a multi meter and connect it on pin 2 and 12 and crank the engine over. This checks the power, ground and input to the PCM. The CKP uses a 12v square wave pattern to tell the PCM where it's at. Using a multi meter will only show you the average voltage.
INJ1/INJ2 are the fuses for the injectors. If the fuses are good verify you have power at the injectors. The pink wire is the 12v ignition power source. If you have power there then you know the PCM is not commanding the injectors to fire.
If you don't have power at the injectors then it's a wiring issue but the chances of two separate circuits being open or shorted to ground are pretty slim. Especially because you have no spark.
07-26-2015, 06:09 PM
#20
On The Tree
Thread Starter
If you have no spark and no injector pulse that points to the crank sensor and/or wiring, IMO
Is your tach still showing RPMS when you crank it?
Have you checked for codes since it won't start at all?
Does the car have headers? If so check the wiring harness that goes down the the crank sensor. I've seen several times that wiring harness gets cooked from the headers.
Also if you haven't, check all your fuses.
What type of scanner/code reader do you have and does it show any live data?
Is your tach still showing RPMS when you crank it?
Have you checked for codes since it won't start at all?
Does the car have headers? If so check the wiring harness that goes down the the crank sensor. I've seen several times that wiring harness gets cooked from the headers.
Also if you haven't, check all your fuses.
What type of scanner/code reader do you have and does it show any live data?