Truck Running Lean

05SBZ71 · April 8, 2008

Hey guys,

Quick question...I have an 05 Silverado with almost 27,000 miles and in the last couple of weeks it seems to be running a bit lean. This happens only every 3 or 4 days and usually not even on a consistent basis throughout the day that it does it. When accelerating up through the gears it seems hesitate, I feel as though I have to press the pedal harder than usual. It will also cut in and out just slightly enough to feel it when accelerating. On a couple occasions when coming to a stop the rpms will drop significantly, one time down to only 200 causing it to stall for just a second before I acclerated. I've spoken to my service manager who I have a good relationship with and he seems to believe that it could be a clogged throttle body. We've eliminated battery, fuel pump, alternator, etc. I'll probably have it looked at when I go in for an oil change, but I was just curious to know if anyone could offer anymore insight. Any opionions would greatly be appreciated.

Thomas

silveradocoa · April 8, 2008

there is a tsb on some truck about a rough or low idle. you clean the TB and do a reflash

leboyd · April 8, 2008

Hey guys,

Quick question...I have an 05 Silverado with almost 27,000 miles and in the last couple of weeks it seems to be running a bit lean. This happens only every 3 or 4 days and usually not even on a consistent basis throughout the day that it does it. When accelerating up through the gears it seems hesitate, I feel as though I have to press the pedal harder than usual. It will also cut in and out just slightly enough to feel it when accelerating. On a couple occasions when coming to a stop the rpms will drop significantly, one time down to only 200 causing it to stall for just a second before I acclerated. I've spoken to my service manager who I have a good relationship with and he seems to believe that it could be a clogged throttle body. We've eliminated battery, fuel pump, alternator, etc. I'll probably have it looked at when I go in for an oil change, but I was just curious to know if anyone could offer anymore insight. Any opionions would greatly be appreciated.

Thomas

A clogged throttle body would be amazing! The service manager said it "could be a CLOGGED throttle body"? I didn't think that was possible, but I guess you learn something new everyday! Or maybe, the service manager doesn't know what he's talking about. It could be a problem with the throttle body, but I don't think you can clog one unless you really try.

Battery? I can assure you it's time to get a new service manager if he suggested checking the battery.

I would start with the fuel filter. A little bad gas (picking up some gunk at the bottom of the barrel) might could do this. And it's cheap, fast and easy.

Does it run differently if it's cold, warm or hot? Once it does it (every 3 or 4 days), can you get it to repeat (e.g., once it happens can you make it happen again)?

There could be a number of things that affect this, but after the filter I would lean towards an electrical problem such as a small break in a wire or something. It could be the pressure regulator - there's just not enough information yet to trouble shoot it.