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Alex
Alex, ASE Certified Technician
Category: Chevy
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Experience:  ASE Certified Master Technician, L1 Advanced Level Specialist
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2005 chevy malibu: 4 cylinder will not start..narrowed..fuel injectors

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2005 chevy malibu 4 cylinder will not start. I believe we have narrowed the problem to the fuel injectors. Fire will get to the injectors but will not break. as long as you pour gas in car will run. we have changed the fuel pump, cleaned fuses, replaced modulator valve ect.
can you help
Hello. My name is XXXXX XXXXX I'll be assisting you with your question.

Have you checked fuel pressure? If so what were your readings? And have you checked for spark and fuel injector pulse?
Customer: replied 6 years ago.

fuel pressure is about 60 pound but we don't understand what spark and fuel injector pulse is. again, fire gets to injectors but does not break to burn the gas

thanks

I see. Connect a test light across the fuel injector connector pins and crank the engine. If the test light flashes, you have fuel injector pulse and you know they are being commanded to fire by the PCM.

Also, when you say you pour gas in, are you talking about at the intake? Or into the tank? Is the security light flashing?
Customer: replied 6 years ago.

We have already tried step one and it was not being commanded to fire, we poured gas in the intake and the security light was flashing. my friend wants to know how or where to locate the spark and fuel injector pulse to test

 

Step one is checking for injector pulse. Since you've already done that and found you have no injector pulse, that is your problem. The security system is disabling the fuel injectors and the PCM is not commanding them to open.

You don't need to check for spark pulse because the engine runs when you pour gas into the intake, so you know you have spark.

What you need to try is the security re-learn procedure. This procedure must be followed exactly. It also must be done with the master key. If you try this and it does not work after several tries, you'll need to replace the passlock sensor, and then do this procedure again:

1. Perform a security system relearn. 2. Let the vehicle sit for more than 10 minutes with the key off. 3. Attempt to start the engine, leave the key in the run position, monitoring the security system indicator. 4. After 10 minutes, the security indicator will change state. 5. Turn the key off and wait 10 seconds. 6. Attempt to start the engine. If the engine stalls, wait another 10 minutes with the key on. 7. After the second 10 minute timer has expired, turn the key off for 10 seconds. 8. Attempt to start the engine. If the engine stalls, wait another 10 minutes with the key on. 9. After the 3rd 10-minute timer has expired, shut the key off for 10 seconds. 10. The security system will relearn on the 4th starting attempt, and the engine should start and run.
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Customer: replied 6 years ago.

You are wonderful, just one more question. Is the security re-learn procedure in the owners manual or where can i go online and print directions, also where is the passlock sensor located. I love this site and i will recommend to all my friends, if you haven't already guess i am a woman who is asking questions for my husband, son and friends

so when you answer this i will gladly pay you for your time

have a great evening

Did the procedure go through on your end? The passlock sensor is located on top of the ignition key cylinder.

1. Perform a security system relearn. 2. Let the vehicle sit for more than 10 minutes with the key off. 3. Attempt to start the engine, leave the key in the run position, monitoring the security system indicator. 4. After 10 minutes, the security indicator will change state. 5. Turn the key off and wait 10 seconds. 6. Attempt to start the engine. If the engine stalls, wait another 10 minutes with the key on. 7. After the second 10 minute timer has expired, turn the key off for 10 seconds. 8. Attempt to start the engine. If the engine stalls, wait another 10 minutes with the key on. 9. After the 3rd 10-minute timer has expired, shut the key off for 10 seconds. 10. The security system will relearn on the 4th starting attempt, and the engine should start and run.
Customer: replied 6 years ago.
would it be a good idea to change the passlock sensor anyway when we reset the security system,
Not necessarily. There's a very good chance the sensor needs to be replaced but I would only replace the sensor if you are unable to get the engine started using the procedure. Sometimes, after a battery disconnect or for other unexplained reasons, these vehicles will fail to start and just need to have the relearn procedure done.
Customer: replied 6 years ago.

Actually we disconnected the battery for 15 minutes and then tried to start, but someone had suggested it might be security problem. the car did not start but we will follow your instructions tomorrow to reset

thanks again

i may be talking to you again tomorrow night, we are mechanic wannabes, because we have not much money, so we try to narrow the problem ourself, because the computer did not show any problem when we tested

 

Thanks let me know how it turns out. Don't forget to click accept if you are satisfied.