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Discussion Starter · #1 ·
Help For about two months I have been having a problem with my 2005 Silverado. The truck is a K3500 extended cab non dually LT truck with a 5 speed allison. After the engine is warmed up to the operating temp. I can not seem to exceed 2000 rpm. As I advance the accelerator I start to lose rpm ,the transmission will down shift ,the rpm will momentarily increase as I continue to slow. When the rpm drops below 2000 the power will return and begin to accelerate again. It does not do this all the time but I get no warning when it will. Once I back off on the accelerator and allow the rpm to decrease I seem to have the power back. If any one out there can help I would appreciate it Thank you........ Alf.
 

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Have you checked your fuel filter? Sounds like you're not getting the fuel volume you need to keep the cylinders charged at the right pressure. Fuel filter replacement would be the cheapest and most likely suspect.
 

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Fuel filter. How long since your last change-out? Try not to let it go more than 10K miles.

You very well could have gotten a bad batch of fuel. It can happen. If its a continuing problem, you may need to run some Power Service 911 treatment or Howe's fuel treatment to get it under control.


BTW, Welcome to the Garage, fellow Michigander.
 

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The first sign of fuel filter plugged is a loss of hi idle power, the power loss goes up at lower rpm on torque rise engines.

A plugged filter is consistent, it does not allow more fuel sometimes.

A fuel filter can plug in 30-40 miles after getting bad fuel and the next filter will last about twice as long. five or six filter changes are possible with a full load of bad fuel befor the fuel is polished enough that it does not plug filters but by that time you will have more fuel ( hopefully from a clean tank).

I would suspect the throttle position sensor may be electrically noisey. Do you have any codes?

keydl
 

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It sounds like its in limp mode.2000RPM is about what they give you in limp mode.Like was emntioned replace fuel filter first,then if that doesnt do it,it may be time to take it in.
 

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I unwrapped my garden hose to wash off the car a week ago. The hose still had some ice in it, but when I put it in the sun and opened the valve pushing the 50 degree water from the pump house onto the ice, the ice jam slowly melted. Back on the other end of the hose I had screwed on the spray nozzle and had opened it up. At first, there was nothing, no air, nothing. But as the ice melted, I began to hear air hissing and soon a slow stream of water was ejected from the nozzle. I closed the nozzle and waited for the pressure to build to the 77 psi I've got it set to in the pump house. I, at first, began to spray the car with short five second bursts from the hose because after that time, the pressure was gone and all that was left was a dribble, so I had to wait again for the pressure to build. I repeated this about ten times before the hose was clear of the ice blockage and then I was able to finish rinsing off the dirt from the car without pausing to let the pressure build again. My point in all this? The fuel filter can allow a certain volume of fuel past it while it's still clogged. It's not black and white. It may be clogged at 60% allowing the engine to work under very light loads. Once a heavier load is put on the engine, however, the volume of required fuel will not be delivered because the filter has a blockage in it. It's entirely probable that the filter can be clogged without causing any noticeable performance problem until you're needing that extra fuel to pull out into traffic. Change it often.
 

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Discussion Starter · #7 ·
Thanks.. I will try the fuel filter and after that I will repost to let you know the results, again thank all of you for confirming my thought process. I bought a new Fram filter and was suprised at the $50.00 price. That would be a little salty if I need to change it every 10,000 miles........ALF
 

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Discussion Starter · #8 ·
Follow up on dura max delima

Thanks to all who replied to my question, The fuel filter seems to have done the trick. Since changing the filter I have experienced no further "limp" mode issues. I was {however} suprised that with all the "WIZ Bang" stuff the driver information center can report that a fuel flow issue is not indicated:thanks: ........Alf
 

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TDG Mafia # 81
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Glad to hear that was your issue, and that you got it resolved. Like Tom said, a fuel filter should be replaced every 10-15K along with the Allison auto transmission filter if you have one.

Tony
 
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