Random misfire

156,000 MILES • 4.3L • V6 • 4WD • AUTOMATIC
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JUSTINV
  • MEMBER
  • 1 POST
I have a random misfire and am stumped. I changed the cap and rotor, plugs, EGR valve, mass air flow sensor, ignition module, ignition coil wire and sprayed carburetor cleaner around intake to check for leak and still the same problem. When I first start my car it idles fine, but after a few minutes it starts to miss and idle really rough until I give it a little gas while in park and it is fine again for a few seconds then starts again. I notice no problems when actually driving the vehicle only seems to be at stoplights or just when I am parked. Please help!
Feb 21, 2017 at 12:29 PM
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STRAILER
  • ✓Experienced Mechanic
  • 55,554 POSTS
Hey,

It sounds like the fuel pump is getting weak, rung this test to see if the pressure is up to where it is suppose to be.

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


Please run this test and get back to us so we can continue helping you.

Best, Ken


Feb 24, 2017 at 3:37 AM
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