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04 grand prix sluggish misses and dies


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dlc723e
New User

May 26, 2012, 9:01 AM

Post #1 of 5 (2041 views)
04 grand prix sluggish misses and dies Sign In

hello, can someone please help me. my 04 grand prix is sluggish when i press the gass petal. the gas petal feels heavy when i press it. when it's low on gas it misses and dies, but it starts right back up. dealership was unable to duplicat the problem. did tune up with fuel injection cleaning. did fuel filter thursday evening. i think the fuel pressure test was done at the dealership. yesterday morning mechanic said he thinks it's something in the engine. he mentioned the possibility of the crank censore or ignition censor. he also mentioned he's almost positive it isn't the fuel pump since it starts right back up and it runs. any ideas on what else it could be?


Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

May 26, 2012, 9:07 AM

Post #2 of 5 (2035 views)
Re: 04 grand prix sluggish misses and dies Sign In

Get a code reading even if CEL isn't lit. May be low fuel pressure and the law is it will give good #s when checkedMad Went thru one last year that every time I checked it was in spec and finally caught it too low,

T



dlc723e
New User

May 26, 2012, 9:11 AM

Post #3 of 5 (2029 views)
Re: 04 grand prix sluggish misses and dies Sign In

at the dealer they said there were no codes


Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

May 26, 2012, 10:18 AM

Post #4 of 5 (2005 views)
Re: 04 grand prix sluggish misses and dies Sign In

Not if they didn't check. If really misfiring this OBDII (96 and up) should be able to say random misfire or pick which cylinder. If they just reset it it may not store a new code right away. It's free (basic check) at more and more mostly parts outlets in many places now. Doesn't necessarily tell you exactly what or why but what area to chase down.

If a place will get you a reading now while misfiring it should show something,

T



Discretesignals
Ultimate Carjunky / Moderator
Discretesignals profile image

May 26, 2012, 11:01 AM

Post #5 of 5 (1992 views)
Re: 04 grand prix sluggish misses and dies Sign In

Any recent repairs done to it before this starting happening? Is this supercharged?


To start off I would monitor fuel trims while driving to see if the PCM is compensating for anything. Long and short term should be around 0 % or less than 10 %. Then I would floor,WOT, while driving and watch the front O2 sensor voltage. It should go rich or around .9 volts. If it doesn't go rich, the engine isn't getting enough fuel at WOT(wide open throttle). That is when you look at fuel pressure and MAF sensor frequency. If the fuel pressure looks good while gunning it, I'd sweep the MAF sensor with an oscilloscope and watch for any drop outs in frequency and see what the max frequency you get out of the sensor at WOT. If the frequency is low, check to make sure the MAF doesn't have dirty elements or something getting up on the diffuser. You can also unplug the MAF sensor and see if your power returns. If power returns when you unplug your MAF, you have a problem with the MAF.





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(This post was edited by Discretesignals on May 26, 2012, 11:10 AM)






 
 
 






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