I have a 2000 RCSB Silverado with a 4.8L and 3.42's and 100k on the odometer.

When im cruising around it seems as though when i give it some gas, its real sluggish; like i'm stuck in too high of a gear. When i put it in tow/haul mode its perfect, but it wont shift into third until after 35 mph and OD until after 60 mph.

What would correct this? Is there an adjustable downshift linkage like on older trucks, or is the downshift electronically controlled?

I know I would benefit from a Torque converter and some lower gears, but I can't afford it right now.

Any advice would be appreciated.

BTW a vette servo and B&M shift kit will go in this weekend.

 

I Have The Same Truck Mine Is Very Sluggish. And Throttle Response Is Horrible

 

The downshifts are controlled through the computer.

I have the same truck with a 5.3L with a 117K and it takes a good amount of gas to get it to downshift. My throttle response picked up quite a bit after I did the top engine cleaner deal to clean all the oil and crap outta the intake/engine. If the computer is pulling timing because of knock retard the top engine cleaner could help out.

I think gears would be the biggest benefit as far as helping out the sluggish feeling. The torque converter while taking off easy from a light or something will make it feel even more sluggish until you give it some gas.

 

What kind did you use...BG 44K is good.

 

That is the perfect description of how my 99 runs! Gotta get major throttle angle before it downshifts. Getting the computer reflashed/tuned is sounding better and better every day!!

 

well if it is fine in tow haul mode then it sounds like your Torque convertor is not unlocking soon enough(thus the too high of gear feeling) when you open the throttle, becuase putting it in tow haul mode only firms the shifts, holds hears longer and delays lockup.

 

mine did the same thing, even with mods it did this. however it has been alleviated with some gears. like xlr8nss said before me. get some gears and it will help more than a tune will.

 

What is BG 44K? I used Amsoil Power Foam to clean the intake/engine out. Works just like Sea Foam or GM top engine cleaner.

 

The only way to change the way the truck downshifts would be to get something like LS1edit, HP Tuners, or a custom tune to change things in the computer.

For seat of the pants feel to make the truck feel less sluggish gears are gonna be the best bet. If you have stock 3.42 gears a set of 4.10s will make a world of difference.

The top engine cleaner is a cheap way to maybe get some better throttle response if your engine is dirty and causing the computer to run low timing.

 

well also, to help on the part throttle acceleration you need to do the free mods. get rid of the egr, port and polish the tb, tb bypass and do the egr trim. however, if you do the egr delete you are gonna need tuning to get rid of the code that is gonna be thrown.