I have 77 targa with a 2.7 engine. I have begun to experience what I am characterizing as a sticky throttle. When I shift gears and remove my foot from the gas the engine does not rev back but actually revs up a couple hundred RPM's. I have lubricated the throttle linkage at the engine to no avail. This problem seems to get worst as the engine heats up. Any suggestions? Thanks.

 

Have you made sure the return spring is still good. Sounds like there is not enough tension on the spring.

 

Are you referring to the spring on the throttle body?

 

I'd offer that 2 of the 3 throttle rod bellcrank bushings are very dirty and perhaps need replacing and lubricating.

One is at the front of the engine on top and off to the left a bit and the other is down by the transmission (left side).

The bellcranks are bushed in plastic that does not last forever and gets gummed up.

 

Yes. Sometimes they lose their tensile strength. Steve is probably more correct in that those bushings get gummed up. I suggest removing them and cleaning them real well and reinstall them. Don't use any Acetone based or Xylene on the plastic stuff because it slowly starts to melt it away. Good luck.

 

Thanks guys. I'm going to check out the bushings and springs.

 

Don't know how the '77 linkage is but on my '73 it's very easy to disconnect the linkage at several points. By seperating the linkage and feeling which side is binding you can very quickly zero in on the joint w/ the problem. For me, it's been the actual throttle body shaft on more than one occasion (only when the car is warm). Good Luck!