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I just recently replaced my plugs and wires, so I decided to clean my throttle body intake and adjust my TPS sensor. While I was in there I accidently knocked this black plastic cap cover off and saw a filter. It was very clean, but could not find where the black cap went. It went under the main throttle body, so long ol buddy, till the starter needs replaced.
Its currently out right now, so I wanted to know if its something to worry about and what it could hurt?
I was wondering what this filter and cap goes too and its purpose? Any idea?
idk what it is but heres where it goes....i started a thread on this s while back and no one knew...i glued it back on and its been there for +6k miles....i wouldnt worry about it i drove without it to to see if anything changed but nothing....its not even connected to anything whatever it is!!! lol...if anyone knowsplease chime in
I found out what it is. Its called the DP ( Dash Pot ). It seems to be just another way to check for correct idle position. It does say not to clean the filter, but to replace it. The idle should be plus or minus 50, and around 700, in park.
I've been trying to figure out what this mysterious thing is/does, as well. I've seen some mentions of it being vacuum controlled, tied to the EGR system, but I don't see any vacuum lines going to it. As far as I can tell, the tip of the dashpot is pressed in by the throttle pin thingie (it rotates up to the right of the TPS) returning to its resting position, and has something to do with bypassing the throttle to smoothly let off the gas.
I'm wondering if it's worth taking mine apart and going through the testing procedures (FI-67). It seems like it moves properly, so probably not. And everything I touch on this $&#@! car crumbles in my hands... However, seeing the pictures in this thread makes me think the filter is worth blowing out with compressed air, same as the nearly identical looking EGR Vacuum Modulator filter.
After looking it over in more detail, I'm all but certain the Dashpot is just a way over-engineered adjustable bump stop for the throttle lever/pin thingie to keep from abruptly shutting the throttle plate when letting off the gas. The "bypass" referred to isn't the DP itself, but what the DP does to slow the closing of the throttle plate at the very end of its travel.
The filter looks to serve absolutely no purpose, other than maybe as a baffle to assist in rebound? It was completely free of dirt, as would be expected from a "filter" that is sealed off from airflow.
The cap on mine came off with little more than gravity to assist in the effort. And not surprisingly, the lip on the cap was half broken off, like every other plastic item on this car. I wrapped it with electrical tape, since gluing ABS is like training a cat, and put back in place.
Revisiting this, as I removed my Dashpot to see if it really does anything. It's definitely what I theorized above -- just a complex bump stop. It supposedly keeps the throttle plate from closing too abruptly when letting off the gas, but other vehicles seem to be fine without it... Maybe it works in conjunction with the IAC to modulate low-RPM bypass air? Here are some pics to help:
Plunger on top, cracked lid on bottom.
Opened up. Filter cartridge sitting in the lid's holder, vent holes and air bladder up above.
The screw immediately to the left of the TPS connectors is part of the pivot attached to the throttle plate; it hits the tip of the Dashpot plunger at the very end of its travel when closing.
There's a spring under the accordion boot of the plunger, and the filter cartridge looks to just be a baffle to keep things quiet, not that you'd ever be able to hear the air being squeezed by the plunger with the engine running. It's truly a bizarre little creation.
With it off the car, I was able to re-tape the lid to seal it up as good or better than when new, in case I decide to put it back on. I'm leaving it in the car for the time being, as it only takes a few seconds to reinstall if needed, but I couldn't tell any difference without it while driving around town today. If it remains an indiscernible difference, I may hack mine up to see if it can be shaved down to just the mounting bracket and plunger, since those are one piece and the plastic filter assembly sits on the end of it. It seems like the spring ought to be able to do its thing without the semi-sealed chamber behind it.
Do you guys happen to have the factory part number handy for this filter piece? It's the same filter for both SC400's and SC300's correct? Mine seems to have gone missing.
I could be incorrect but it looks exactly the same as the one for SC300's.
09-29-10, 03:17 PM
What is this?
