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Hello everyone, i have owned my g8 gt for 2 weeks already and have loved it, besides a little issue that i cant seem to trace. Im no mechanic by any means but know my basic way around cars. So ive been having a problen with the acceleration of the car. I cant seem to floor it on a dead stop because itll just stop dead on its tracks and just slowly accelerate until it picks up speed and even then when it picks up speed ut sort of like "hiccups" when picking up the speed. Other times i can gun it from a dig and itll accelerate smoothly with no issues. Ive done research and it had the possibilty of bad spark plugs so i changed those along with new cables and it didnt seem to do anything. Any ideas?
 

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What you're describing could also just be traction control, especially with crappy tires. Try turning TC/ESC off and then CAREFULLY do another launch.
 

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Im not getting any codes, it passed smog recently as is. How would i check for vacuum leaks? And ill try the traction control, but engine just seems to lose power when accelerating. The other day i also noticed the stock exhaust manifold has some bolts missing from it. Idk if this would affect it?
 

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but engine just seems to lose power when accelerating
How else do you think TC works? It cuts power when it detects wheelspin. If your problem goes away when you floor it at higher gears, this strongly points to TC. If the problem exists at higher speed when you punch it, then it is more likely an engine-related issue.

The exhaust bolts could cause it to bog at low rpm, but that'd be met with a CEL most times. Regardless, find the replacement bolts! haha
 

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As far as im aware, its not tuned. I tried it without traction control and it did it regardless. I also noticed it does it under 2k rpms then just resumes normally. Itll miss a bit sometimes at WOT. And yeah i do need those bolts lol
 

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It does it at any speed as long as its under 2k rpms, after that it picks up nice. I have to ease into the throttle for it to accelerate smoothly. It still sort of like misses or hiccups sometimes in the higher rpms. Ive done the traction control trick and still same thing. Ive checked grounds, vacuum lines, new spark plugs and wires and all seems ok just dont know what else to narrow it down to. Ever so rarely i can accelerate smoothly.
 

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Current mileage of the vehicle?. Also, a short video of the engine bay under acceleration might be helpful. Could it be the air:fuel ratio is not optimum and it's getting too little air and too much fuel? If so, have you checked the air filter? The reverse could be true which would lean towards a vacuum leak as previously mentioned. Without any computer data showing what the ecm is seeing then you're essentially "taking shots in the wind". Could be a partially clogged fuel injector as well. Good luck
 

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Depending on mileage I might lean towards a dead or dying coil along with injectors or fuel pump. But that is only if it is not the exhaust manifold. At low rpm air can enter there causing a lean condition, which the pcm would then cut power if its knocking or (more typical) dump a ton of fuel. You need to reset your LT fuel trims, replace the missing bolts and the manifold gasket, and I would also do the O2 sensor if it was me.
 

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So the miss at higher rpms is gone. The spark plugs and wires seemed to work. I still have that annoying bogging at those low rpms. I took it to a mechanic so he can inspect the manifold leak and he said the leak is barely noticeable and that the missing bolt wont do much of a difference with my bogging. He pointed to the air filter which to me seems really dirty and almost clogged. So ill try that and he also said that it maybe can be my tranny oil since the engine doesnt bog down like that in those rpms in park. Tranny seems to run hot and sometimes reaches 105c so could that be the culprit?
 

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Pull the air filter and see if that fixes it. If so buy a new one. 220F is about normal on the high side when the oil is passing through the radiator in the summer. I swapped my pan and filter for the Camaro one though and it made a drastic difference.
 

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As far as im aware, its not tuned. I tried it without traction control and it did it regardless. I also noticed it does it under 2k rpms then just resumes normally. Itll miss a bit sometimes at WOT. And yeah i do need those bolts lol
I had a similar issue to what you are describing, changed plugs and wires and it went away.
 

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Martinez7409 did you find the problem? I’m having the same issue but I’m losing timing from the engine. New plugs, wires, maf sensor, and air filter. Only code is p0449 evap leak. Any help would help.
 

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Hello everyone, i have owned my g8 gt for 2 weeks already and have loved it, besides a little issue that i cant seem to trace. Im no mechanic by any means but know my basic way around cars. So ive been having a problen with the acceleration of the car. I cant seem to floor it on a dead stop because itll just stop dead on its tracks and just slowly accelerate until it picks up speed and even then when it picks up speed ut sort of like "hiccups" when picking up the speed. Other times i can gun it from a dig and itll accelerate smoothly with no issues. Ive done research and it had the possibilty of bad spark plugs so i changed those along with new cables and it didnt seem to do anything. Any ideas?
My G8 GT still does this and I have replaced spark plugs, wires, all intake manifold gaskets, and more, but have had no improvement. Fortunately, it has never gotten worse but after 2 years, it still annoys me. I have just never found the smoking gun and I don't have any codes from this either. I can confirm that it is not a traction issue.
 

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i can gun it from a dig and i till accelerate smoothly with no issues. Ive done research and it had the possibilty of bad spark plugs so i changed those along with new cables
 
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