My car seems to studder while gently accelerating?

Tiny
TMCKENZIE
  • MEMBER
  • 2009 SATURN AURA
  • 65,000 MILES
It revs up just fine, I checked the fuel pressure and it's running at 60psi and when the engine is reved up it stays at 60psi. I pulled the injectors and they seem to be working fine. But while I'm driving 45-75 mph I can feel the car studder. The tach also flutters a bit when I can feel it. It only use to do this when I would push on the gas and put some load on the engine ( first noticed it when going up hill slightly )now it does intermittently while driving on flat roads also. I don't know what else to check. It's not putting any check engine lights or codes on. 2009 Saturn aura 2.4lL
Friday, July 20th, 2012 AT 7:51 PM

8 Replies

Tiny
SATURNTECH9
  • MECHANIC
  • 30,869 POSTS
Is it worse with the ac on?Also have you checked for codes I kniw you said you dont have any but did you check for any?
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Friday, July 20th, 2012 AT 8:03 PM
Tiny
TMCKENZIE
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  • 5 POSTS
I checked it for codes today, it didn't have any. I haven't checked with ac off. I will
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Saturday, July 21st, 2012 AT 12:13 AM
Tiny
SATURNTECH9
  • MECHANIC
  • 30,869 POSTS
If its worse with ac off its most likey a ignition issue spark plugs failing coil etc.
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Saturday, July 21st, 2012 AT 1:05 AM
Tiny
TMCKENZIE
  • MEMBER
  • 5 POSTS
I just drove it and it seems to bit worse with the ac off, it shutters more frequent. I also forgot to mention when I pulled the injectors one of them came out pretty tuff and the nozzle looked a bit burnt, the others looked nice and clean. How can I test the coil packs? And would one be going bad without throwing a check engine with a code?
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Saturday, July 21st, 2012 AT 4:12 PM
Tiny
SATURNTECH9
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Iam sorry I ment to say if it was worse with the ac on?So is it worse with the ac on?Also if one of the injectors tips looked burnt that would be a dirty injector since there is really nothing at the tip of the injector to be burnt.I have bad coils set codes and have also seen them not set codes.
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Saturday, July 21st, 2012 AT 5:09 PM
Tiny
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Is there a way I can test the coil packs?
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Saturday, July 21st, 2012 AT 6:08 PM
Tiny
TMCKENZIE
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  • 5 POSTS
I drove it again and yes your right its more pronounced with the ac on. I can feel it when it's off, but turned back on its much more noticeable.
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Saturday, July 21st, 2012 AT 8:30 PM
Tiny
SATURNTECH9
  • MECHANIC
  • 30,869 POSTS
I posted a trouble tree for the ignition system dont replace anything just follow the trouble all the way down. That way you can test the wires etc. Heres the problem with a problem like your having it is a coil issue which we dont know that it is. Its only failing under load I also dont put much faith in testing the coil with a ohms meter. My sisters honda had no spark only had one coil it tested good ohms wise. Found a plused trigger to the coil so I new the coil was bad. It sounds like a coil issue since with the air on it cuts out worse. Most of the ones I have seen like that turned out to be a ignition issue.I would also check the spark plugs visually look at them for cracks black carbon etc.
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Monday, July 23rd, 2012 AT 7:59 PM

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