no power right after 6.0L starts

[apolahar08]

i have a 200 silverado 2500 6.0L and it has no power when i start it up. its like it is only running on 4 cylinders and it bogs down. if i put it into drive and floor it it doesnt go past 2500 rpm's. i replaced fuel filter and pump and fuel pressure regulator. the problem goes away after about 45 seconds and then it runs alot better. still a little wierd around 1000-2,000 rpms though... please help!!

[T.M.I.]

i have the same trouble with a 99 2500 cant find the problem any suggestions.

[vncj96]

I would start with ignition components, plugs, wires, coils and distributer. They are easy to inspect and can be tested for froo at autozone or oriellys, then you arent just guessing and throwing parts at it.

[T.M.I.]

I have run tons of tests and scaned it . i even took it to 3 garages 2 dealers and no ansers. the truck has lots of new parts fuel pump ,filter,plugs,wires,map senser,temp senser. also changed mas air flow and idel air control. still runs bad for about 30 to 60 sec runs ok after that until i shut it off .start it back up same thing .

[eyegore]

I have an '07 with the same issues. Bogs down and crappy performance on a cold start. Had computer reflashed and updated. Seem to help for awhile. GM tech told me that I should try a custom tune with a programmer from a performance shop. Have not done it yet so I can't comment if it works. Worth the try, just hasn't been on the top of my priority list.

[T.M.I.]

How bad was the power loss ? And did the flash tune fix it or just temporarily?

[eyegore]

With mine, it was somewhat temporarily. It did some good but not perfect. Will be trying to find a custom tune from a performance shop in the near future.