Engine turns over but will not start?

1996 BUICK CENTURY
210,000 MILES • 3.1L • V6 • 2WD • AUTOMATIC
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SAMSONCRASS
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  • 2 POSTS
When I go to start up my car listed above, it will turn over, but it will not start. I have checked my fuel pump/filter and there doesn’t seem to be any issue there, though I don’t have a pressure gauge to verify correct fuel pressure. I can also smell fuel in the engine compartment when turning it over. I have also ruled out the idle air control valve and the MAF. Very occasionally, the vehicle will start but it won’t hit a proper idle before it shuts off. I do have a voltmeter and a mostly full set of tools but I’m at a loss on where to go from here.
Jun 21, 2023 at 2:01 AM
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MATHGEN
  • ✓Experienced Mechanic
  • 128 POSTS
The first thing I would do here is to test for good spark at the spark plugs. You can use a spark tester, or a spark plug attached to the plug wire and properly grounded.

Here is a video that should help:

https://youtu.be/baq_aEWNQ0Y


I have also attached a diagram of the plug wire layout for your engine. Note that there are three separate coils, I would test each one to make sure they are all working properly. If you have good spark, then I would move on to testing the fuel system. Most parts houses, Napa, AutoZone, etc. have a loaner tool program where you can get a fuel system pressure tester.
Here is a link on how to test the fuel delivery system. The blue circle on the diagram shows the location of the test port.

https://youtu.be/peh7-pFycyc

The fuel pressure for this vehicle should be 41-47psi.

Please let me know what you find and if you need further assistance and we will take it from there.
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Jun 21, 2023 at 11:26 PM
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SAMSONCRASS
  • MEMBER
  • 2 POSTS
Fantastic! I’ll run those tests first thing tomorrow morning and post the results.
Jun 22, 2023 at 9:06 AM
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STRAILER
  • ✓Experienced Mechanic
  • 55,249 POSTS
MATHGEN is one of your best! Please let us know how it goes.
Jun 25, 2023 at 4:46 AM
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