Sticky agressive throttle fix

[SledZ]

I could not stand the "sticky agressive" throttle any more. It is where you start to give it gas and it kind of sticks and then gives, making it hard to get a smooth start. After reading all the posts this appears to be a common problem on the early Z's and I could not find any pictures except for the tech article on ZHOME.COM

I decided to take off the "arm" grind off the weld and reposition it to see if I could get it to smooth out.

As you can see in the pictures it did not take much of a turn, in fact I would turn it a bit LESS because I had to shorten the top rod almost to it's max and unscrew in the accelerator rod a 1/4" to get the throttle to open all the way.

The reason I didn't repostition it again is because I really welded it up to much and didn't want to grind it off again and I thought I could adjust it more with the rods.

I can say for sure that it worked fantastic. The whole day I drove around I kept expecting the "stick then give" but it is as smooth as a new car. I can start at idle and slowly bring it up to any rpm.

Also if you have a new throttle boot this is the time to replace it. My neck is still out of joint!

[SledZ]

Here is what the throttle rods looked like before

[SledZ]

This is how it looked after

[halz]

At last someone has posted pictures of this fix - thanks!

From my research into the problem, there appeared to be two methods to address the issue. Yours was one way. The other was to replace the short rod that connects the throttle shaft to the parallel throttle actuator with a slightly longer version that has a slight curve in it. Both methods aim to overcome the initial resistance in the throttle assembly that we all experience in the standard setup.

You have spurred be to address this problem once and for all!

[panchovisa]

Guys,

Just be careful that at full throttle opening the belcrank is still moving towards the carb throttle linkage!!!! If not, the harder you push your throttle pedal you'll actually start closing the carbs down.

[Mr Camouflage]

Originally posted by panchovisa

Guys,

Just be careful that at full throttle opening the belcrank is still moving towards the carb throttle linkage!!!! If not, the harder you push your throttle pedal you'll actually start closing the carbs down.

I suppose you could adjust the pedal stop so that this wont happen.

[panchovisa]

What am I thinking! Never mind! I got the motion of bellcrank backwards. Dooh!

[kmack]

Originally posted by halz

The other was to replace the short rod that connects the throttle shaft to the parallel throttle actuator with a slightly longer version that has a slight curve in it.

This was the way I addressed mine. But I didn't swap out for a slightly longer rod. I just put a slight kink in mine and it took about 80% of the "stickyness" out of the throttle movement. If I ever decide to get the remaining 20% out, then I'll re-work my bell crank. But for now, it's SOOO much better!

[240ZX]

I had the same issue with my Z. However, at the time it had mucho miles on it and the throttle linkage was pretty loose, well used at best! I read articles that described the problem and some even went to the extent of fabricating and or modifying the existing set-up. Well, that is what I had in mind at the time too! But, here is what I did and it works smooth as butter now. First off I went about eliminating the excessive tolerances that occured from 30+ years of use in the linkage. Secondly, I adjusted the adjustable part of the linkage to minimize the camming effect (hard to push initially and then it get's easier all of a sudden) to a minimum. And thirdly, I replaced the two return springs with a pair of lighter Stainless steel springs. Of course I did some testing to make sure they were not too light! I now have a throttle that works smoothly and with good control. In addition, I attribute some of the smoother take offs to the addition of a 13 1/2 lbs flywheel......which originally everyone said was a bad idea for the street because it would be hard to drive!!??!!?? Well, the truth is that it actually drives much easier with the light flywheel than with the stock unit.......go figure!?

Just one man's opinion................that works!