One day I was driving and when I turned the engine off it would start back the crankshaft position sensor was bad but I replaced it any ideas of what might be my problem
2003 Trailblazer LT Ext cranks but wont start no fuel pressure
- Thread starter TrailblazerLTExtended
- Start date
Mooseman
Moderator
Cranks but won't start
When I turn the key on my 2004 trailblazer it will not start.Just keeps cranking.I have replaced the ignition switch and it still won't start.Could anyone please direct me on common issues that may be causing my trailblazer to not start?
gmtnation.com
What led you to replace the CKP sensor? Does the fuel pump run at all? Does it prime? Tried jumping the fuel pump relay? Does it run then? Check fuses? Check power to the relay?
I am assuming we are talking about a 4.2 EXT? Doesnt he have to do a crankshaft relearn after replacing that?
Strongly recommended but not likely to cause a no start situation.
Yup... IF he can Figure Out (and Fix) whatever the issue is that is Stopping the Engine from Starting.
OP... The Details? The MORE... The Merrier. :>)
The CASE Re-Learn Instructions (for Tech 2 Owners) to follow after (1) Changing the PCM, (2) Replacing or Rebuilding the 4L60E Transmission (3) Replacing the (CKP) Crankshaft Position Sensor.
Connect a scan tool to make sure there are no trouble codes stored in the computer’s memory. If there is any power train trouble code other than P1336 (Crankshaft Position Variation not learned), the computer will disable the relearn function until the problem that caused the code has been eliminated. Also, make sure that the engine coolant (check it when the engine is cold) and oil levels are at an acceptable level.
1. Set the parking brake and block the drive wheels. Make sure that the hood is closed.
2. Start the engine and make sure that the engine coolant temperature is at least 158 degrees F.
3. Turn the engine off for at least 10 seconds.
4. Select the crankshaft position variation learn procedure (CASE Learn)on your scan tool.
5. Make sure that the transmission is in Park. Start the engine.
6. Apply the brakes and hold the pedal firmly.
7. Follow the scan tool instructions.
CAUTION: You are going to increase the engine speed to approximately 3000 RPM, 4000 RPM, or 5150 RPM. That’s the variation learn fuel cutoff RPM (depending upon the engine), and that it’s important to release the throttle when the engine RPM starts to decrease as a result of the fuel cutoff going into effect. Failure to do such will result in over revving of the engine, causing possible engine damage.
8. Once the engine has returned to idle, check the status of Diagnostic trouble code P1336. If the scan tool indicates that the CASE has been learned, the relearn procedure is now complete. If CASE has not been re-learned, check for the presence of other Power Train Codes. If any exist, correct the problems, then repeat this Re-Learn Procedure.
OP... The Details? The MORE... The Merrier. :>)
The CASE Re-Learn Instructions (for Tech 2 Owners) to follow after (1) Changing the PCM, (2) Replacing or Rebuilding the 4L60E Transmission (3) Replacing the (CKP) Crankshaft Position Sensor.
Connect a scan tool to make sure there are no trouble codes stored in the computer’s memory. If there is any power train trouble code other than P1336 (Crankshaft Position Variation not learned), the computer will disable the relearn function until the problem that caused the code has been eliminated. Also, make sure that the engine coolant (check it when the engine is cold) and oil levels are at an acceptable level.
1. Set the parking brake and block the drive wheels. Make sure that the hood is closed.
2. Start the engine and make sure that the engine coolant temperature is at least 158 degrees F.
3. Turn the engine off for at least 10 seconds.
4. Select the crankshaft position variation learn procedure (CASE Learn)on your scan tool.
5. Make sure that the transmission is in Park. Start the engine.
6. Apply the brakes and hold the pedal firmly.
7. Follow the scan tool instructions.
CAUTION: You are going to increase the engine speed to approximately 3000 RPM, 4000 RPM, or 5150 RPM. That’s the variation learn fuel cutoff RPM (depending upon the engine), and that it’s important to release the throttle when the engine RPM starts to decrease as a result of the fuel cutoff going into effect. Failure to do such will result in over revving of the engine, causing possible engine damage.
8. Once the engine has returned to idle, check the status of Diagnostic trouble code P1336. If the scan tool indicates that the CASE has been learned, the relearn procedure is now complete. If CASE has not been re-learned, check for the presence of other Power Train Codes. If any exist, correct the problems, then repeat this Re-Learn Procedure.
Mooseman
Moderator
The lack of a CASE relearn would not cause a no start condition, only set a cam/crank correlation error code. In fact, the engine has to be running to do it.