It is a plunger that the throttle rocker (whatever its called) rests against when the throttle is closed. When opened, the plunger slides up. I am asking because I noticed the movement of the plunger is delayed, i.e. when I open the throttle, the plunder slowly moves up and when I allow the throttle to quickly close, the plunger has some resistance that delays the action. I am wondering if it should behave this way or if the action of the plunger should be instantaneous.
Thanks for playing and I'll post another pic for perspective.

 

Dash pot, cuts down back fires.

 

 

suppose to work the way you described it.

 

Wow, that was quick--thanks. Any insight into how it works or if it should be instant action vs. delayed response? Would the motor response be improved if it were instant?

 

I call it Steve! ... no, seriously... you said "Name this Part!"....

okay... it's purpose is to keep the throttle from closing too quickly and causing the engine to run rich until the ecu can catch up with things.
It's vacuum controlled, meaning the more vacuum it gets, the less effect it has on the throttle since engine vacuum is higher as the throttle gets closer to being closed. More vacuum pulls it further away from the throttle lever. Get it?

 

when the thottle closes it prevents it from slamming shut by slowly closing it. Does nothing on exceleration (?sp)

 

acceleration

 

if it is operating properly, it can actually help acceleration particularly during gear-shifts.

 

mine stuck one day so I removed it. so used to rev matching the old fashioned way now I don't notice it being gone.

 

what exactly is REV-MATCHING?

 

rev-matching is getting the engine at the rpm necessary to freely engage the next gear, without relying on the synchro's

 

Rev Matching kind of brings me back to the reason I am asking:
The delay on closing the throttle (revving down...?) is kind of annoying. I understand that it helps things stay smooth during shifting and that it allows the fuel control to catch up so I don't plan on messing with it. But, it feels less "connected." Like the action of the car is not connected immediately to the input of the driver. For me, this is kind of important.
My last car was an '87 16 valve GTi with about as much modification as can be California legal (exhaust, cams, decked head, etc.)
It was nice and quick (certainly not fast by modern standards) but what I really loved about the car was the immediacy and the responsiveness. If I blipped the throttle, it wound up and dropped quickly. I don't expect the Toyota to be in the ballpark in this regard, both because it is Japanese vs. German and because it is a completely different animal with a different purpose, BUT, I am always trying to find ways to make it more drivable and by that I mean "connected"; as close to immediate and accurate response to driver input as possible.
Anyway, I know I am in the minority on this forum talking about "drivability" rather than "wheelability" but thanks for the responses and let me know any tips for any improvements in this regard.

 

@SC2WD- ever wonder why VW dropped the CIS-E (KE-Jetronic) system?
CIS-E was mechanical injection with electronic controls built on top.

 

I hadn't really thought about why they dropped it. I know a lot of people complain about it being finicky but I had great luck with mine. (In fact, I think I still have a complete fuel injection set up, brand new in my garage.) Sounds like you know something about Volkswagens...?
Enlighten me about the system!

 

I had a 78 and 81 VW Scirocco way back when, so I know a thing or two about the old K-jetronic Bosch systems. The KE was the norm when I ridded myself (after many objections- the car had frame damage) of the 81.

For a given engine configuration, the mechanical nature of the CIS system worked well, actually better than a full electronic system could at the time, but emissions controls didn't work well with it. They made it work up to the late 80's, early 90's though. The frequency valve concept let them custom tailor the mixture more than the fuel distribution plate could on its own. After that, the mechanical aspects couldn't compensate for conditions quickly enough, or rather electronics caught up and could do thinks more quickly, so it went full electronic.

 

One more question. Why will Volkswagens only work properly with Bosch components while Toyotas will barely work at all using Bosch?

 

bosch designed the system used by the VW's.... ND (NipponDenso) engineered the components to work with the Toyota design?

 

yup yup.. hit the nail on the head there.. now from what i have heard toyota motors dont like bosch or autolite spark plugs and wires for some reason.. never dealt with it cause iv always ran NGK or Denso..has any one heard this one?

 

Hmmm....I've heard NGK was about the best you can run for Toyota's. I've never had good luck with Bosch or Autolite...IMHO they are junk.

Oh yeah...the first and second pictures are of your throttle body...duh!