Pontiac Problems? Ask a Mechanic for Answers ASAP
Hi, I’m Cary and I’ll be helping you today.Please understand that I can't smell, hear, or touch the vehicle, so patience is appreciated. Before leaving the site make sure and leave me a rating. You can still reply to me as many times as needed, even after the rating..
Does the vehicle ever shut off while driving or just will not start on start-up?
Have you noticed if the anti-thief light is on or flashing when it fails to start?
How often does it fail to start?
I have to go. I will opt out now so another expert can help.
Hello, my name is ***** ***** I'll be happy to assist you! I have an associates degree in automotive technology, I’m ASE certified with 15 total years in the field. Let me gather some information to help.
So we are on the same page your sure you have spark and the security light goes out while cranking. You have also noticed the injectors do not pulse. Have you noticed with a stethoscope listening for the click or do you have a noide light or voltmeter?
I've researched my database for similar problems and it backs up what I've seen at my shop. Without further testing it is likely the PCM (engine computer) is faulty. The fuel injectors are controlled internally by the PCM and the drivers can burnout. It usually starts as an intermittent problem and gets worse as you described. There are a few tests you can do if you have a multimeter or test light. Or if cheap enough maybe try a junk yard PCM to swap in as long as the engine and trans from the donor car are the same!
Let me know what else I can do to help. I can try to give you some test steps if you don't wanna gamble on the PCM.
Well in the field i would monitor the cam and crank sensor signals to be sure. You have spark so crank sensor should be ok and you already replaced the cam sensor. It is possible you have a wiring problem somewhere so thats why I would want to verify the signals with a capable scanner. You can test the injector electrical signals going out to the injectors with a test light. You would have to unplug the electrical connector to one of the injectors and place each end of the test light on each pins in the electrical connector of the injector. During cranking the pcm should make the test light flash with each injector pulse. If the test light doesn't flash then you know it is either the PCM or the wiring going to the injectors. I can provide wiring diagrams if you feel it will help. Let me know if I can further assist.
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Thanks again and I hope I was helpful!