When the motor is not running, the throttle shaft rotates smooth and steady. However, when the motor is running, the throttle shaft doesn't want to rotate when you try to first move it. It feels like your having to push it through a little invisible wall or something. Of course, once you push through that little bit at the start, it's okay. Well, it's okay until I let off the gas, and then I get to do it again.
I've tried lubricating about everything I can get to, but no change. Any ideas what might be causing this.
Thanks

 

the vaccume in the manifold is what causes that increased resistance. The outside air pressure puts force ont he throttle blades causing the shaft to bind. remove and check the shaft/ tb for wear and put some thick grease on the shaft and reinstall it. see if that helps

BTW, welcome aboard

 

btw.. i think its something like 40 lbs of force on the plates at 20 inHg in the manifold off the top of my head.

 

Just a thought, but check if your cable connecting pedal to throttle bracket is at the right length, in good shape and lubed up ok.

 

It's most likely the throttle cable itself binding, Lube that up first, it's easier..

 

He could always adjust the min air rate, and instead of following procedure exactly, he could open the throttle plates a little more and let the IAC decrease its idle counts to compensate. Might reduce that initial force to open the plates. I don't think I have any such thing on my car.

 

i had this same thing happening to me but it wasnt the cable. Worked fine as long as the engine wasnt started. Start the engien and the peddle was hard to depress initially. Cleaned and lubed the shaft and that fixed it.

 

I had the same issue with my throlltle blades sticking. I had adjusted the Min idle speed and the throttle blades were resting on the wall or the bore and the eventually, through heat and vibration, wore a groove in the bore of the TB and they would stick. So i turned the little screw a little and get them off the bore walls and no more problems.

-lars

 

Thanks a bunch for this incredible response. I have tried the basic stuff as far as checking and lubing the cable and the throttle linkage assemblies inside the car and on the throttle body.
Looks like it might be the shaft itself. I'll pull it apart Sunday and see if that might fix it. Either way, I really appreciate all the good advice. Thanks a lot.
Joe

 

mine does the same thing but only when it is cold it shure can be a pain in the as$ but oh well i live with it mabe once my procrastination wears off ill fix it!
Chris.

 

mine did the same thing....when i took the motor out and put it back together... the problem just went away.i must have done something to it...2 bad i dont know what