bfg Posted January 27, 2013 Share Posted January 27, 2013 I have a 75 280z and the pedal doesn't like to return lower than 1500. It was worse before but after lubricating all the joints between the pedal and the engine its gotten much better but not perfect. after inspecting I found that the spring that pushes the pedal back is pretty weak. Anyone know where I can find one? Quote Link to comment Share on other sites More sharing options...
Nigel Posted January 27, 2013 Share Posted January 27, 2013 What about the throttle body spring? The throttle body spring is what is intended to produce the throttle return force. The pedal spring only has to be strong enough to support the weight of the pedal. Nigel '73 240ZT Quote Link to comment Share on other sites More sharing options...
bfg Posted January 27, 2013 Author Share Posted January 27, 2013 That could be it. The entire linkage setup seems to be worn down so I'd like to replace it but I'm not sure where to get it. Is there a place to get springs for Z's or can I go to the hardware store and get something as close as possible? I'm also thinking about doing the throttle cable conversion as I've heard its relatively easy. Quote Link to comment Share on other sites More sharing options...
NewZed Posted January 27, 2013 Share Posted January 27, 2013 The early 280Z's PCV system allowed dirty blowby gases to deposit crud around the throttle blade. Nissan moved the hose in 77. I had a similar problem as yours on my 76, with the RPM hanging high after everything got warm. I fixed it with carb cleaner and Scotch-brite. Remove the hose from the AFM to the throttle body and see what's in there. Quote Link to comment Share on other sites More sharing options...
Tony D Posted January 31, 2013 Share Posted January 31, 2013 Crud on the T/B bore is why the factory had you clean it each tune up interval. It's also the reason the heat hoses go to there---keeps the T/B warm at small throttle openings. It makes that PCV Sludge freeze up solid---and your throttle can stick open a bit further than 1500! Keep it clean, and warm, and you're golden. The linkage itself is designed over-center---that is, it self returns because of mechanical loadings. But it depends on unbinding free travel to keep everything light and linear. Quote Link to comment Share on other sites More sharing options...
siteunseen Posted January 31, 2013 Share Posted January 31, 2013 I had that same problem too on my 9/'76 until I re-routed the hoses like a '78 has them. Quote Link to comment Share on other sites More sharing options...
bfg Posted June 24, 2013 Author Share Posted June 24, 2013 I finally got around to replacing my PCV valve. (I know It's been slow going) Everything seems to be clean and no change. The throttle sticking was getting worse since I got the car registered and on the road so I figured it was time to do something about it. I think I'm going to try replacing the throttle return spring next. Quote Link to comment Share on other sites More sharing options...
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