| I just finished doing this on 3ZC and thought some here might benefit from it.
Setting and Synchronizing Throttle Bodies
This is my own personal approach on the subject. I've done this sort of thing over the years on my motorcycles with the aid of either vaccum guages and/or carb stix (mercury stix).
However, since those sort of tools won't be applied here, a more rudimentary approach will be taken.
This sort of undertaking is by no means difficult and requires only the basics of tools to complete. It appears that since the Z32 is now at the 20 year mark, certain parts are starting to show their wear. This is no different when it comes to the Throttle Bodies (TB's). After 20 years of having the butterfly slamming against the venturi of the TB, it's understandable that there's going to be a certain amount of wear. However, since there are two TB's, it's concievable that both may not wear at the same rate over the course of 20 years.
In the same token, the throttle linkage may also have worn slightly which will also compound the issue. Worn throttle linkage settings and worn TB butterfly settings can combine to produce significant idle/performance issues. To begin with we'll look that the TB's first.
The effects that worn TB's can produce would be an inconsistant idle and/or low speed/throttle hesitation. This can be attributed to having an unequal amount of air getting past each TB butterfly.
To correct this a few steps need to be taken to ensure each is set correctly to provide equal amount of air passage. 1. In order to facilitate this project, it would be stronly advised to do a thorough cleaning of each TB before hand.
Removing the TB's would be highly suggested but not 100% necessary. There are directions in the Factory Service Manual (FSM) for this but it's a fairly straight forward process anyway. I'll describe this procedure with the TB's removed. For those that are not removing the TB linkage, you will need to loosen the set stop screw on the outer part of the TB linkage that makes contact with the main throttle linkage arm. This will prevent the TB from having a pre-mature stop point from that linkage set-screw setting. We'll get back to that later. See Throttle Linkage set screw to the far left in this pic. It needs to be loosened first if the TB's are not removed from the plenum.
2. Once the throttle linkage stopper effect is removed from the equation, we can focus on the TB itself.
Placing the TB's up to the light and looking through them we will no doubtedly see some light around the peripherals of the TB butterfly. We want to try to eliminate this as much as possible.
To do this we need to loosen the TB butterfly set stop-screw so as to allow the butterfly to travel to it's max closed position by aid of it's spring mechanism. To visually see the difference may be difficult to the naked eye.
I would next open the butterfly by hand and place a thin strip of paper between the butterfly and the venturi and let the butterfly gently close pinching that piece of paper.
By applying minimal pulling pressure on that strip of paper I will adjust the butterfly set stop screw so to the point where the butterfly will start to allow the slip of paper to move forward. At that point, lock the set screw nut down. You may want to confirm this a few times until you're satisfied you have that minimal clearance. Try not to rip that piece of paper in half for obvious reasons.
Do the same procedures as mentioned above for the other TB.
Now that each individual TB is set to their own fully closed position, we now have to make sure that each will open at the exact same time.
The thottle linkage has a fixed blade arm at the either end.
 
As I mentioned before, the TB outer set stop screws (the ones closest to the throttle linkage) make contact with the main linkage's fixed blade arm as seen here.
Those fixed blade arms must move each TB linkage at the exact same time. Having a third person at this point would be advantageous.
While your helper ever so slightly moves (pulls) the throttle cable you need to visually see that each TB linkage is moving at the exact same time.
Again, each TB has it's own set screw adjuster to make the necessary adjustments so that each will move at the same time.
I didn't want to rely on my visual acquity so I returned to the thin strips of paper again. By placing a thin piece of paper in both TB's, I would get my helper to very slowly pull on the throttle cable. Ensure beforehand that there's adequate slack of the throttle cable to begin with.
The object here of course is to apply equal pull pressure on those strips of paper while the throttle cable is pulled slowly and have them release at the exact same time. When one is released sooner you will have to adjust those outer set screws (your choice) until those pieces of paper release at the same time.
If you're so inclined, you can step back and visually observe your handiwork with your helper moving the throttle cable.
At this point, ensure your throttle linkage set screw nuts are locked down and you can replace your intake hoses.
Now that we've ensured that each TB is hitting it's max close point and that each TB is opening and closing at the exact same time and that the throttle cable tension has been correctly set, we've finished with the TB setting and synchronizing. But we're not altogether completely finished.
I neglected to mention at the beginning anything about removing the TPS prior to starting as I assumed that that would be a given. Now that we're done with the TB's we need to re-install the TPS and correctly set for the targetted .42V to .44V. *Those voltages are my preference*
Once that is done, we should have a much more responsive throttle without any hesitation and hopefully a much better idle as well.
Depending on the extent of our corrections made to the TB's, it may be necessary to go back to the normal idle setting procedures. I strongly recommend the FSM with the Swipnet links for setting your idle.
Hopefully this will be the last time one would have to do this during the course of ownership of their Z32. La-Z-Link
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Throttle Body Setting and Synchronizing - 
