Shut off while driving will not start

Tiny
POWMEMAW
  • MEMBER
  • 2005 CHEVROLET TAHOE
  • 5.3L
  • V8
  • 4WD
  • AUTOMATIC
  • 200,000 MILES
My SUV shut off going down the road one day. After it sat for awhile it started, but smelled like sulfur coming from the exhaust. Thought it was the catalytic converter. Fixed it still had the same problem. Had it put on a code reader, said it was the fuel pump, replaced it. Ran for a week, quit running the same way going down the road, and now wont start, and not getting any fire.
Saturday, February 15th, 2020 AT 5:35 PM

2 Replies

Tiny
KASEKENNY
  • MECHANIC
  • 18,907 POSTS
When you say it has no fire, does that mean you don't have spark on the plugs or it is just not starting?

We need three things to start the engine. Spark at the right time, fuel, and compression.

Let's assume compression is okay for now but we need to narrow down the spark and fuel. Try using starter fluid in the intake and see if it fires. If so then we have a fuel issue. If not, pull a plug and connect it back to the coil then hold it against the engine block and see if it sparks.

Let me know about this and we can go from there. Thanks

https://www.2carpros.com/articles/car-cranks-but-wont-start

https://www.2carpros.com/articles/how-to-test-engine-compression
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Saturday, February 15th, 2020 AT 6:29 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 108,103 POSTS
Hi,

If you have no spark, there is a good chance it is related to the crankshaft position sensor. There are conditions where is can fail and not set a code.

Take a look through these links:

https://www.2carpros.com/articles/how-a-crank-shaft-angle-sensor-works

https://www.2carpros.com/articles/symptoms-of-a-bad-crankshaft-sensor

https://www.2carpros.com/articles/crankshaft-angle-sensor-replacement

Now, the easiest way to determine if that is the issue is with a live data scanner. Basically, you plug it in, go to live data, and watch for an RPM signal when cranking. If there is no signal, chances are it is the sensor.

Here are the directions specific to your vehicle for replacement. The sensor is actually behind the starter. The attached pics will correlate with these directions, and I will provide the relearn procedures after the replacement process.

________________________________

2005 Chevy Truck Tahoe 4WD V8-5.3L VIN T
Crankshaft Position (CKP) Sensor Replacement
Vehicle Powertrain Management Sensors and Switches - Powertrain Management Sensors and Switches - Computers and Control Systems Crankshaft Position Sensor Service and Repair Procedures Crankshaft Position (CKP) Sensor Replacement
CRANKSHAFT POSITION (CKP) SENSOR REPLACEMENT
CRANKSHAFT POSITION (CKP) SENSOR REPLACEMENT

REMOVAL PROCEDURE

IMPORTANT: Perform the CKP System Variation Learn Procedure whenever the crankshaft position sensor is removed or replaced.

pic 1

1. Remove the starter.
2. Disconnect the crankshaft position (CKP) sensor electrical connector.

pic 2

3. Clean the area around the CKP sensor before removal in order to avoid debris from entering the engine.
4. Remove the CKP sensor bolt.
5. Remove the CKP sensor.

INSTALLATION PROCEDURE

pic 3

1. Install the CKP sensor.

NOTE: Refer to Fastener Notice in Service Precautions.

2. Install the CKP sensor bolt.

Tighten the bolt to 25 N.m (18 lb ft).

pic 4

3. Connect the CKP sensor electrical connector.
4. Install the starter.
5. Perform the CKP system variation learn procedure. See: Vehicle > Programming and Relearning

________________________________________________-

2005 Chevy Truck Tahoe 4WD V8-5.3L VIN T
Crankshaft Position (CKP) - Variation Learn Procedure
Vehicle Testing and Inspection Programming and Relearning Crankshaft Position (CKP) - Variation Learn Procedure
CRANKSHAFT POSITION (CKP) - VARIATION LEARN PROCEDURE
CKP SYSTEM VARIATION LEARN PROCEDURE

1. Install a scan tool.
2. Monitor the powertrain control module (PCM) for DTCs with a scan tool. If other DTCs are set, except DTC P0315, refer to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information for the applicable DTC.
3. Select the crankshaft position variation learn procedure with a scan tool.
4. The scan tool instructs you to perform the following:
1. Accelerate to wide open throttle (WOT).
2. Release throttle when fuel cut-off occurs.
3. Observe fuel cut-off for applicable engine.
4. Engine should not accelerate beyond calibrated RPM value.
5. Release throttle immediately if value is exceeded.
6. Block drive wheels.
7. Set parking brake.
8. DO NOT apply brake pedal.
9. Cycle ignition from OFF to ON.
10. Apply and hold brake pedal.
11. Start and idle engine.
12. Turn the A/C OFF.
13. Vehicle must remain in Park or Neutral.
14. The scan tool monitors certain component signals to determine if all the conditions are met to continue with the procedure. The scan tool only displays the condition that inhibits the procedure. The scan tool monitors the following components:
- Crankshaft position (CKP) sensors activity-If there is a CKP sensor condition, refer to the applicable DTC.
- Camshaft position (CMP) signal activity-If there is a CMP signal condition, refer to the applicable DTC.
- Engine coolant temperature (ECT)-If the engine coolant temperature is not warm enough, idle the engine until the engine coolant temperature reaches the correct temperature.

5. Enable the CKP system variation learn procedure with the scan tool.
6. Accelerate to WOT.

IMPORTANT: While the learn procedure is in progress, release the throttle immediately when the engine starts to decelerate. The engine control is returned to the operator and the engine responds to throttle position after the learn procedure is complete.

7. Release throttle when fuel cut-off occurs.
8. The scan tool display reads Test In Progress.
9. The scan tool displays Learn Status: Learned this ignition. If the scan tool indicates that DTC P0315 ran and passed, the CKP variation learn procedure is complete. If the scan tool indicates DTC P0315 failed or did not run, refer to DTC P0315. If any other DTCs set, refer to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information for the applicable DTC.
10. Turn OFF the ignition for 30 seconds after the learn procedure is completed successfully.
11. The CKP system variation learn procedure is also required when the following service procedures have been performed, regardless of whether or not DTC P0315 is set:
- An engine replacement
- A PCM replacement
- A harmonic balancer replacement
- A crankshaft replacement
- A CKP sensor replacement
- Any engine repairs which disturb the crankshaft to CKP sensor relationship.

______________________________

Let me know if this helps. Also, if there are new codes set, let me know what they are. One last thing. The rotten egg smell, like you already know, is related to the catalytic converter. However, often the smell is a result of a rich fuel mixture damaging the converter. Once it is up and running again, make sure the fuel pressure is within spec.

One last thing. There is a common ground for all the coils on this vehicle. It should be located on the driver's side of the engine below the cylinder head. It is somewhat common for the ground to break down and loose contact or even just break. It will be a black wire. If it failed, you will lose spark. Interestingly, if it is a weak ground, I'm wondering if it may have caused an uneven or incomplete burn of the fuel which led to the smell and converter issues. If this is the problem, you will have an RPM signal indicating the crank sensor is good.

Let me know if this helps or if you have other questions.

Joe
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Saturday, February 15th, 2020 AT 6:30 PM

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