Bucking, misfiring and cutting out

2001 BUICK CENTURY
170,000 MILES • 3.8L • 6 CYL • 2WD • AUTOMATIC
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TOOLSGREGORY
  • MEMBER
  • 2 POSTS
The vehicle will bucks, misfires and sputters under load. We replaced the MAF sensor. No change. Scoped the crankshaft position sensor. The pattern is a nice square wave and it says good when the bucking is going on. Misfire monitor shows no coil misfires. Fuel pressure is good. No codes are showing or pending
Oct 11, 2019 at 9:59 AM
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TOOLSGREGORY
  • MEMBER
  • 2 POSTS
Update on the Buick century. The customer said cost was no option. We replaced the crankshaft position sensor, with again no fix. Pulled that off and put it back together. Next was the ignition control module. Finally we had some improvement. But now we had a constant misfire under load. We were getting a low number of misfires on number 4 monitor, around 6 to 14 per cycle. The wires were just replaced a few months ago and they looked great, so we then went with the number 4 1 coil. This is what the problem was from the beginning. We figure the coil was shorted out to the control module, as the 4/1 coil sits above the electronic part of the ignition module. We will not be forgetting about this one for a while. Thanks for letting me share, GH
Oct 11, 2019 at 4:51 PM
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KASEKENNY
  • AUTOMOTIVE REPAIR CONTRIBUTOR
  • 18,907 POSTS
Hi,

Well you made it easy on us. Next time you post something we will make sure to give you a few hours again before we respond to see if you fix it. Just kidding.

Sorry we didn't get to you sooner but glad you got it fixed. Thanks for posting that info as well. I am sure that will help others that have a similar issue.
Oct 11, 2019 at 5:29 PM
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