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Discussion Starter #1
Hi guys new to the forum here,

So I have a MKIV na 93 model, have owned it for a while, just finished putting it back together after I stripped it and gave it a lick of paint,

I am having issues with my Idle, I have a new TPS new IACV I have thoroughly cleaned the throttle body,
When driving the idle sticks like I have cruise control unless I quickly stomp the throttle it then goes back down to a high idle, just revving the car in the shed it still sticks but when I push on the part of the throttle that closes the dashpot it brings the idle down, I can’t wind the dashpot adjuster screw any further to help close it, I was going to add another spring to help the situation but would rather fix it properly,
I have two dashpots and they both seem to function the same press in and release fine.

Any help would be greatly appreciated.
 

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From the land down under
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4,217 Posts
Welcome neighbour :)

Are you 100% sure that you installed the IACV correctly, and that its functioning correctly?

When you say, dashpot, what are you referring to? Its not a term I have heard used in this situation.
 

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Discussion Starter #3
Welcome neighbour :)

Are you 100% sure that you installed the IACV correctly, and that its functioning correctly?

When you say, dashpot, what are you referring to? Its not a term I have heard used in this situation.
Hey mate,
Dashpot is the little black plunger looking thing under the throttle cables and such,
Yeah IACV was installed correctly and is showing the correct values,
 

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96 JDM TT 6sp
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A dashpot is one of these. Like a hydraulic dampener. Between the ETCS stepper motor and the TPS on my stock TT throttle body.
254090
 

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96 JDM TT 6sp
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Hi guys new to the forum here,

So I have a MKIV na 93 model, have owned it for a while, just finished putting it back together after I stripped it and gave it a lick of paint,

I am having issues with my Idle, I have a new TPS new IACV I have thoroughly cleaned the throttle body,
When driving the idle sticks like I have cruise control unless I quickly stomp the throttle it then goes back down to a high idle, just revving the car in the shed it still sticks but when I push on the part of the throttle that closes the dashpot it brings the idle down, I can’t wind the dashpot adjuster screw any further to help close it, I was going to add another spring to help the situation but would rather fix it properly,
I have two dashpots and they both seem to function the same press in and release fine.

Any help would be greatly appreciated.
Let me know if you need any measurements or similar. I have a stock version of an NA and TT throttle body here. I'm near brissy/GC for what it's worth :D
 

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I had drivability issues on my 94 Turbo. The car suddenly would idle a little erratically and seemed to get extra throttle input when I let off the gas. I figured it was the IACV. Then I tried this: I knew the issue was intermittant so as the car idled at around 800 or so, I disconnected the IACV connector. This resolved the issue of the erratic idle and throttle. However it has left me with no IACV funtion.

I believe the capacitor in the ECU for the IACV failed and caused this erratic operation. This, even after I had the ECU rebuilt months before with all new capacitors.

So, try disconnecting the IACV if you can get the car to idle properly for a moment. If that works, consider trying a spare ECU that is known to work properly. Yes, I think we all should have a spare ECU as a tool for diagnostic purposes.
 

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From the land down under
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I had never known the throttle closing damper was referred to as a dashpot haha.

Agree with the above ^ A known working ECU is a great diagnostic tool for our aging steeds
 

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Discussion Starter #9
Cheers guys for the reply’s and info I am using a known working ECU, I took the throttle body and gave it a good and through clean, going to install it again today and see if any change, just trying to eliminate things one at a time
 
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