engine surging/pulsing...

[DucatiSSsp]

Hi Mr. Tech

Just bought a 06 sierra 1500 4x4 5.3 special edtion package. Noticed at steady 50mph I'm getting a slight engine FI pulsing. Also this truck does not seem to get up and go like a coworkers chevy 5.3. I really have to stomp it to the ground to get it to kick in and go. only one time have I stomped on it and it responded like i think it should. still less than 500 on the odo. I am planning on taking it in soon but would like your opinion. truck seems to run fine otherwise but above 2k rpm seems lethargic.

TIA,

Bryce

[GM-Tech]

Without actually experiencing it myself, and with only your perception rather than some hard diagnostic facts, it is hard for me to form an opinion. What you feel is lethargic may seem perfectly normal to me.

 

Don't compare to your buddy's truck unless it is identical in every respect. Same year, gearing, 4x4, etc. Even if it's an identical truck in all those areas, there are still some manufacturing tolerance differences that could make one vehicle operate slightly different than another truck.

[High Mileage]

Hi Mr. Tech

Just bought a 06 sierra 1500 4x4 5.3 special edtion package. Noticed at steady 50mph I'm getting a slight engine FI pulsing. Was this problem ever resolved? I've got an 02 doing the same thing. At around 1500 rpm it is really noticable. It seems like the tourqe converter is sliping in and out of lock up as I can see the tach fluctuating 50 to 100 rpms. Hope you can respond. Thanks

[Mo Mason]

I have a 2000 Silverado 4X4 Z71 5.3L that surges between 40-50 mph. The tach fluctuates 50-100 rpms. I can hear the engine surging it is very noticeable, nothing imagined. At highway speed 70-80 mph there is NO surging. I can smoke the tires off the line, no problem. Even get second gear scratch sometimes, no problem. But just trying to hold a steady 45 mph and it surges up and down. I have replaced the fuel pump and fuel filter. Put a pressure gauge on it and it goes to 50 psi and holds there, at idle. Any ideas appreciated.

 

MO

[Mo Mason]

I have a 2000 Silverado 4X4 Z71 5.3L that surges between 40-50 mph. The tach fluctuates 50-100 rpms. I can hear the engine surging it is very noticeable, nothing imagined. At highway speed 70-80 mph there is NO surging. I can smoke the tires off the line, no problem. Even get second gear scratch sometimes, no problem. But just trying to hold a steady 45 mph and it surges up and down. I have replaced the fuel pump and fuel filter. Put a pressure gauge on it and it goes to 50 psi and holds there, at idle. Any ideas appreciated.

 

MO

 

At first I thought this to be fuel related but I am beginning to think it maybe a transmission problem. Vacuum leak? Don't know where to go from here. Somebody point me in the right direction. Please.