ive got a problem that i hope you guys can help me out with we have had a problem with the car shuddering/shaking under load .. it dosent matter speed,rpm,or temp

ive got a 04 Impalla ss 3.8lt supercharged auto

list of mods and whats been done

- stock motor
- stock supercharger
- K&N cold air
- Gibson cat back
- 1.5" drop springs
- new plugs and wires
- new sc idler pully
- new front upper dog legs
- new drive shafts
- new lower control arms
- 2x - 4 wheel alinement done
- trans flush per service manurel
- no play in ball joints or tie rods
- changed tires and rims to make sure no problems there

untill lately evything was fine but now eveytime you give it some gas the car shakes like your on a washboard

looking for some ideas before i have to put a new tranty in it as its the only thing that i can think of

thanks

 

Shudder makes me think of lack of fuel. Injectors possibly? My girlfriends car "shuddered" like you described under load as well, i popped the hood and messed with the injectors and it went away immediatly. Just an idea.

 

good idea .. ill have to have a look at that .. when i changed plugs they all looked good and light brown not white but thanks for the idea