Intermittent not starting issue

Tiny
JERRICASPELTS
  • MEMBER
  • 2009 PONTIAC G6
  • 2.4L
  • 4 CYL
  • 2WD
  • AUTOMATIC
  • 182,200 MILES
I've changed the new battery, alternator, starter, key modular, both cam shaft position sensors, and checked the relays. So when I go to start it sometimes it starts just fine other times it don't does not. Like when the battery is drained no lights on the dash thing and sometimes the lights come on but it don't start. And when it does start and I try driving it it will go but then just shuts off, and it wont start again for a while. But I don't have to mess with anything try moving wires to see if that get it to start. Or I can try starting it try again and again and I can get it to start sometimes. I have no clue what's wrong.
Friday, September 18th, 2020 AT 3:19 PM

9 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,101 POSTS
Hi,

What you described sounds like it could be a connection issue. Are the battery terminals clean and tight? Also, have you checked body grounds from the battery as well as the ground from the battery to the engine block?

https://www.2carpros.com/articles/everything-goes-dead-when-engine-is-cranked

Let me know.

Joe
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Friday, September 18th, 2020 AT 8:15 PM
Tiny
JERRICASPELTS
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I forgot to put that the battery terminals are new and yes they are tight on the battery and to the block and ground.
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Saturday, September 19th, 2020 AT 2:41 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,101 POSTS
Does this only seem to happen when the engine is warm or could it be anytime? Also, when you experience this, does it eventually start working again? Is there anything you can think of that seems to prompt it to happen?

I'm sorry for so many questions. It sounds like a connection issue, so I'm trying to determine what you should check. Hope you understand.

Joe
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Saturday, September 19th, 2020 AT 6:56 PM
Tiny
JERRICASPELTS
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  • 1 POST
No questions are totally fine, I have no idea and I can't afford to take it to a shop. But the car don't ever stay running long enough to even get warm. And no I haven't been able to get the car running for more then a couple minutes, before it shuts off. Only thing that's happened was my son who went to mechanic school decided to be lazy and didn't want to change the starter so his not so smart friend that quit the same school did. It started and ran fine. My son then drove it to a town about 35 miles away and he said it shuts off 5 times on his way there. I went to see what was wrong and found that his friend didn't have the starter on tight at all because he cross threaded the nut I fixed it still wasn't fixed. Next day went back and changed both cam shaft position sensors. It started right up ran for ten min backed it up and went forward was fine, I left my son drove it to the stop sign that's about 2 or 2 in half miles down stopped and it shut off wouldn't start. So before this I changed the battery and terminals about 5 months, before any of this. And then the alternator went out I changed a week before the starter, then I changed the camshaft position sensor, then the key modular and that's when I checked the relays. That's the order of the things I did. It has almost half a tank of gas. My sister says the catalytic converter is plugged, I say timing or electrical. But I've wasted enough money on guessing can't be doing that.
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Monday, September 21st, 2020 AT 7:04 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,101 POSTS
When you repaired the starter that was installed, the terminals are tight now, correct?

As far as it running and then stalling, have you checked to see if there are diagnostic trouble codes stored? Also. When it fails to start, does the starter still engage? If it does, have you checked for spark and fuel to the engine?

A bad crankshaft position sensor can cause a similar issue, but not the power refusing to turn on dash lights.

Let me know. If the lights on the dash are still showing problems when this happens, you have a bad connection at some point. It could be corrosion, a partially broken wire not allowing enough power to flow, and so on. And yes, I agree with you that it sounds electrical (especially if the lights are still not working all the time). A plugged catalytic converter will cause engine power loss, poor running conditions, and usually a rotten egg smell.

Let me know.
Joe
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Monday, September 21st, 2020 AT 7:14 PM
Tiny
JERRICASPELTS
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Yes, the starter is tight now, and it does not stall it either won't start and the times it does start it shuts off maybe a minute or two after. The check engine light was on but after I changed the cam shaft sensors it turned off hasn't been back on since. The starter engages and the fuel pump you can hear it click in. The spark plugs I have not checked or the coil pack.
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Friday, September 25th, 2020 AT 10:24 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,101 POSTS
Hi,

What will need done is to check for spark and fuel when the car doesn't start. Although you hear the fuel pump, it may not be producing enough pressure. Or, you may be losing spark due to a faulty crankshaft position sensor.

It seems as if you have a scan tool. If so and it can read live data, if the engine doesn't start, see if there is an RPM signal when cranking the engine.

If that isn't possible, then we need to do it a different way. Here are two links. One explains how to check for ignition spark and the other fuel pressure.

https://www.2carpros.com/articles/how-to-test-an-ignition-system

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

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

Take care,
Joe
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Friday, September 25th, 2020 AT 9:14 PM
Tiny
JERRICASPELTS
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  • 1 POST
Quick question my stepdad said check the VVT sensor. I have no idea what that is for, what it does, or where it is. Could that be a possibility or no? I will try what you said tomorrow and see how it goes. Thanks so much.
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Saturday, September 26th, 2020 AT 12:59 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,101 POSTS
Hi,

If the sensor fails, the computer will adapt to a predetermined setting allowing the engine to run. Plus, it will set a code related to a cam sensor, VVT actuator and so on.

Let me know.

Take care,
Joe
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Saturday, September 26th, 2020 AT 5:29 PM

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