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I have an 03 Pontiac grand am with the 3.4. Heres the problem, when it's idling below 1000 rpm it shakes but when you throttle up it smooths out, I just recently replaced the intake gasket a couple days ago and it was not doing this before. I'm assuming an air pocket in the fuel rail or maybe some injectors going bad but I'm open to suggestions. Plz any ideas will help

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2 Answers

Can't have air in the fuel rail,the air would blow
out thru the injectors as soon as they pulsed
When you say (I just replaced) does that mean you
do your own work,because if you paid a shop, they
failed to smoke test the repair,road test or anything else
& put the problem in there
Sounds like a vacuum leak but could be other issues,there
before or added to when intake was done
Did you put a vacuum gauge on it
There is a lot on the internet on how to read
those gauges

Posted on Jul 24, 2013

  • Jake Glidewell Jul 25, 2013

    Vacuums should be good...I'm leaning towards the MAF sensor being out of whack...I've seen it on some of the trucks at work, yes I do my own work I'm a diesel mech but this gas v6 **** I'm at a loss, will try the ITV and throttle body as mentioned in one of the other solutions suggested, may also have a sensor going bad, who knows with this car, thanks for the help tho


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  • Cars & Trucks Master
  • 5,494 Answers

The idle may just be a bit too low. Clean the inside of the throttle body assembly with a sensor safe cleaner, and also the idle control valve or motor. The passages under the idle control can get gummed up, too.
Fuel rails do not get air trapped inside, and a bad injector would not get better as rpm's go up. It's probably something else.

Posted on Jul 24, 2013


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