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Discussion Starter #1
I just bought an 04 duramax and when i accelerate slowly it starts surging up to about ten mph, then once it shifts its smooth until i stop again. I don't think it the fuel filter. A friend said that theres a sensor on the fuel pedal and maybe it wasn't sensing correctly. Anyone else having this problem and or know how to fix it?
Thanks
Robert
 

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Hi :
I have an 05 and was doing the same as that surging all the time , I finally replaced th fuel pressure regulator and that cured the problem .
 

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Discussion Starter #4
where is the fuel pressure regulator? i have noticed that it surges between 1200 and1700 rpm. if you pick up speed fast its fine, but going slow-like across a parking lot, it surges to the point you have to let off the throttle and let it settle down. Ive heard several possibilities like- a bad injection pump, bad injectors, bad fuel filter, but know one seems to know. i changed the fuel filter and that didnt help
 

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I was thinking there was a dealer reflash for surging???
 

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There is a reflash. It doesn't address most surge issues, like the one described here. I have remedied almost all surge issues with EFILive, it is a matter of logging fuel pressure and fuel pulse, then locating the offending areas on the stock tune, and correcting/smoothing that area. Works very well.

Most people have this surge in the LLY, but most don't really notice it because it is in a transient rpm range that we don't spend much time in.
 

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Mine surges a bit but it isn't too anoying. I guess some are worse than others.
 

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Discussion Starter #10
so it sounds like there is a fix for the problem, but which is the fastest, easiest, best, and cheapest?
Thanks
 

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Low speed surge

I have a 04.5 2500HD which has an over sensitive throttle. Travelling over a rough road at low speeds causes slight changes in throttle pressure which in turn causes the surge. Had it to the dealer four time but he has been unable to correct the problem.
 

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that is not a surge technically. It is operator induced feedback. A bump causes the throttle open, causes the foot to come off, etc.

It happens when braking some large aircraft as well, its called a PIO, pilot induced oscillation. But I know what you are referring to, it can also me minimized by using an EFILive created throttle table that is not so sensitive in the fist half of pedal travel.
 

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Finally some light at the end of the tunnel. This problem has had me tearing my hair out for the last year.
Is EFILive the only way to created a throttle table. Can I use one of the plug in tuners to dampen the throttle response.
 

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my LLY was the same way and then i put a PPE tuner on and it is better then before but not quite as steady as my LBZ,so i'm not sure if there is a cure avalible for that problem but i'm sure there is stuff avalible to make it better..good luck
 

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Is EFILive the only way to created a throttle table.

Can I use one of the plug in tuners to dampen the throttle response.
1. yes and 2. no. Be careful. There are several ideas of what surge is, and different causes for each.

I suggested EFI, because it allows you to log and see the surge, then draw conclusions on where it can be fixed. No other diagnostic tool has this capability, certainly not a handheld tuner.
 

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not to steal the thred but im having a simliar problem when i start to drive around 1100 rpm in first my truck surges bad like its trying to shift to secound but cant then it will finally shift and no more surge even at 1100 rpm only surges while moving in first if in park nuturel drive at a idle no surge what so ever if im in park i can rev to 1100 and no surge if im in drive and i break torque to 1100 no surge its only when im moving in 1st gear any suggestions tranny going out it has 270000 miles idk its past to my knodkege never a tuner on it it was all stock when i got it
 
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