2011 5.3 hesitates on start-up

[LaserBlueZ71]

This only happens when the truck sits for more than 5 or 6 hours.

 

I start the truck, it fires, then hesitates to where it almost dies, than it takes off and runs normal. It doesn't ever actually stall, but it comes very close to it, only for a second or two. Whether or not I leave the key in the ON position for a while first to let the fuel pump run, makes no difference at all. Every time the truck sits for more than 5 or 6 hours, it starts like this. If I run the truck, then go use it again a few hours later, it starts with no hesitation.

 

2011 Silverado 5.3 AFM Flex Fuel, 6 speed, always run on Chevron 87, AFM is disabled via a Trinity tuner.

 

Thanks!

[Doug_Scott]

First thing I would do is remove the Trinity tune, put back to stock, and see if it still happens. Quickest way to eliminate half of the possibilities.

 

I am only bringing this up because while reading the post my mind was going off in one direction while I was comprehending what I was reading, only to have to forget all that and switch to the much simpler "slow/rough idle" that you actually meant. Hesitates when talking about engines, is a term that is used when you step on the gas pedal, and the engine does not respond right away, it pauses, or hesitates. What you have is that the engine fires right up, then idle speed drops below normal, close to stall, then picks right back up to normal. It is no big deal, just that it makes it a lot easier to describe something using more correct terms.

 

I am not picking on anyone, not being grammar police, I am just pointing out how it impacted me.

[LaserBlueZ71]

First thing I would do is remove the Trinity tune, put back to stock, and see if it still happens. Quickest way to eliminate half of the possibilities.

 

I am only bringing this up because while reading the post my mind was going off in one direction while I was comprehending what I was reading, only to have to forget all that and switch to the much simpler "slow/rough idle" that you actually meant. Hesitates when talking about engines, is a term that is used when you step on the gas pedal, and the engine does not respond right away, it pauses, or hesitates. What you have is that the engine fires right up, then idle speed drops below normal, close to stall, then picks right back up to normal. It is no big deal, just that it makes it a lot easier to describe something using more correct terms.

 

I am not picking on anyone, not being grammar police, I am just pointing out how it impacted me.

No no, it doesn't fire right up.

 

The engine catches, but only barely, then the RPM's fall away for a second until the engine almost dies, but it catches itself before it dies, then idles normally. Also, the truck is not running a tune. I simply disabled the AFM, but I did not load an after market tune.

 

I will try and get a youtube video of it.

Edited January 29, 2015 by LaserBlueZ71

[LaserBlueZ71]

Here we go.

 

If you turn up your speakers, you can hear the engine catch, almost die, and then run good.

 

 

[waumo1]

I have a 2011 and I'm not sure I would even think there was anything wrong from watching/listening to the video. I must not be getting it.

[Tman2900]

Did you ever get this solved? My truck has started doing the same thing.