I have an 87 Renix 4.0 liter throttle body and the throttle shaft return spring look like it is getting weak and loose on the throttle shaft. The throttle shaft does not close all the way, all the time, causing it to idle high when its not closed all the way. I recently cleaned the throttle body with carb cleaner, so it is not dirty inside.

Also it looks like this is the only spring between the gas pedal and throttle shaft.

Does anyone know where I can purchase a new throttle return spring for this 87 throttle body?

 

Mabey the dealer. I would say screw it, if you need a new throttle body, get an intake manifold and TB off of a new model for more power and better fuel economy. If you dont want to do that then I would get another TB from the Junk Yard. Good Luck!!

 

I'm sure all you need would be a spring hooked to the throttle shaft(anything suitable) then rig up a mount to secure the other end.