What causes the motor to run fine for 10 or 20 mins then die?
MEMBER606
MEMBER
1992 PONTIAC BONNEVILLE
168,000 MILES
It starts ok, idles ok, then drive it for 10 mins it will start missing out then die.
Monday, December 5th, 2011 AT 3:00 AM
19 Replies
JACOBANDNICKOLAS
MECHANIC
109,772 POSTS
It could be an ignition or fuel problem. Does the car start righ back up? If not, when it doesn't start, check to see if there is spark and fuel to the engine. Also, check fuel pump pressure.
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Monday, November 5th, 2018 AT 7:08 PM
MEMBER606
MEMBER
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It doesnt start back up untill it's completely cooled down, I changed the spark plugs and the old one which are only a few months old had really bad carbon deposites, before I did it wouldnt start at all, Im thinking its bad gas bu Im not for sure, could it be he ignition coil packs? Or does it sound like bad gas?
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Monday, November 5th, 2018 AT 7:08 PM
JACOBANDNICKOLAS
MECHANIC
109,772 POSTS
It sounds like either a bad crank sensor or fuel pump. When it doesn't start, check for spark and fuel to the engine. One will be missing. Then we will know what circuit to focus on.
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Monday, November 5th, 2018 AT 7:08 PM
MEMBER606
MEMBER
15 POSTS
Ok that narrows it down, I did two different diagnostics and no code came up at all, whats the best way to check for spark or fuel? If a code doesnt come up does that mean the crank sensor is fine?
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Monday, November 5th, 2018 AT 7:08 PM
JACOBANDNICKOLAS
MECHANIC
109,772 POSTS
No, it could still be bad. Go to our homepage under the DIY section for detailed instruction for checking both. There is also a video for checking fuel pump pressure.
Let me know what you find.
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Monday, November 5th, 2018 AT 7:08 PM
MEMBER606
MEMBER
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Ok, thank you so much for your advice, it does sound like a crank sensor to me but before I assume that I will check the fuel pressure and check for spark, and yes I will definitely let you know what I find out, again thank you
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Monday, November 5th, 2018 AT 7:08 PM
JACOBANDNICKOLAS
MECHANIC
109,772 POSTS
Sounds good. Make sure you check for both when it won't start.
Look forward to hearing from you. Also, if you need a fuel pressure gauge, most parts stores will lend or rent them.
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Monday, November 5th, 2018 AT 7:08 PM
MEMBER606
MEMBER
15 POSTS
Ok, I did a spark and fuel test, and I found spark to the plugs but theres no fuel coming from the test valve on the motor, not even a little, so does that sound like a fuel pump?
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Monday, November 5th, 2018 AT 7:08 PM
JACOBANDNICKOLAS
MECHANIC
109,772 POSTS
Either a bad pump or a plugged fuel filter. Disconnect the filter and connect gauge there to see if there is pressure. If none before the filter, then the pump is most likely bad.
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Monday, November 5th, 2018 AT 7:08 PM
MEMBER606
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Awesome, thank you, I shall do that and see how it turns out.
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Monday, November 5th, 2018 AT 7:08 PM
JACOBANDNICKOLAS
MECHANIC
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Sounds good.
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Monday, November 5th, 2018 AT 7:08 PM
MEMBER606
MEMBER
15 POSTS
I have one more question, some one told me a relay sounds more likely than a pump because he said fuel pumps dont work then not then work then not, but if hes right how could I tell if I have a bad relay? Or do you think hes wrong?
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Monday, November 5th, 2018 AT 7:08 PM
JACOBANDNICKOLAS
MECHANIC
109,772 POSTS
First, pump do go in and out working. However, you can simply check the relay by switching it with a different relay in the relay box with the same part number. I'm sure you will find a match. Switch them and see if there is any difference.
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Monday, November 5th, 2018 AT 7:08 PM
HOMER1967
MECHANIC
875 POSTS
I would bet on the i.C.M. Which is your ignition control module. It's underneath the three coils, remove it and take it to your local auto supply store and they should be able to test it for you and it's usually free. Then go from there. This is a very common issue with these cars/engines. And you have all the symptoms
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Monday, November 5th, 2018 AT 7:08 PM
MEMBER606
MEMBER
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Ok I had another theory, I tried changing out the fuel pump relay which on my car is under the passenger side glove box next on top of the secondary fuse box and it fired right up and ran the whole time but it idled at 2000rpms and didnt go down, then I turned it off and it wouldnt start back up, so does this still sound like a fuel pump problem?
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Monday, November 5th, 2018 AT 7:08 PM
MEMBER606
MEMBER
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I successfully installed a new fuel pump and that didnt fix the problem, and it gets adequate spark, so the only other thing I can think of is the throttle, what do you think?
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Monday, November 5th, 2018 AT 7:08 PM
JACOBANDNICKOLAS
MECHANIC
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Make sure proper pressure is making it to the fuel rail and the injectors are getting power.
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Monday, November 5th, 2018 AT 7:08 PM
MEMBER606
MEMBER
15 POSTS
Would that indicate a bad icm if no power reached the injectors? And I checked fuel pressure again and the test valve shown no pressure but I disconnected the feed from it and fuel blasted out, but I wanted to hear your opinion before concluding anything, could that mean a bad regulator?
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Monday, November 5th, 2018 AT 7:08 PM
MEMBER606
MEMBER
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I think I have found the problem, the check engine light did not light up untill the car died again, so right then and there I did a diagnostic, trouble code 58 came up and it said fault with anti-theft system, can you tell me what to star looking at like the module itself or a relay?