Last x Days Posts  1 | 3 | 7 Days  Search  Topics  Tree View  Help
  Soarer Central * Mechanical - TT * General Mechanical * Low idle all of a sudden???? Previous Previous    Next Next  

Author Message
Scott Wilkes
Tinkerer
Tasmania
TT

Posts: 19
Reg: 10-2008

Top of pagePrevious messageNext messageBottom of page Link to this message

Rating: N/A
Votes: 0 (Vote!)

Saturday, October 25, 2008 - 03:48 pm, by:  Scott Wilkes (Scottywilkes) Quote hilighted text Edit Post Delete Post Print Post   View Post/Check IP (Moderator/Admin Only) Move Post (Moderator/Admin Only)

ok, got the car a week ago, everything is going great, yesterday i went to get lunch from work, came back, shut it off and went back to work, when i started it back up at the end of the day, instead of starting and sitting on 12-1500 on choke, it dropped straight down to 600 revs, even when off choke before it would idle at 7-800 revs.

I removed the idle speed motor and cleaned it out, pulled the plugs to make sure the coils and plugs are ok, but none of that made a difference. Any idea what it could be causing this? As it did it so suddenly.

Also if u tap the throttle when its idling, it hicups a bit and then takes off.

Car runs beautifully, in boost, out of boost etc, has the same power as before, just idles really low. Thanks
Rob Rojo
Goo Roo
NSW
Soarer TT

Posts: 1108
Reg: 12-2007

Top of pagePrevious messageNext messageBottom of page Link to this message

Rating: N/A
Votes: 0 (Vote!)

Saturday, October 25, 2008 - 08:46 pm, by:  Rob Rojo (Rob_tt) Quote hilighted text Edit Post Delete Post Print Post   View Post/Check IP (Moderator/Admin Only) Move Post (Moderator/Admin Only)

I would try to reset the ECU first if you have not already done so.
Rob Rojo
Goo Roo
NSW
Soarer TT

Posts: 1109
Reg: 12-2007

Top of pagePrevious messageNext messageBottom of page Link to this message

Rating: N/A
Votes: 0 (Vote!)

Saturday, October 25, 2008 - 08:48 pm, by:  Rob Rojo (Rob_tt) Quote hilighted text Edit Post Delete Post Print Post   View Post/Check IP (Moderator/Admin Only) Move Post (Moderator/Admin Only)

And then would be looking at the voltage from the TPS. Voltage at 0% throttle should be around 0.50v and at 100% throttle around 3.8v
Scott Wilkes
Tinkerer
Tasmania
TT

Posts: 20
Reg: 10-2008

Top of pagePrevious messageNext messageBottom of page Link to this message

Rating: N/A
Votes: 0 (Vote!)

Saturday, October 25, 2008 - 09:48 pm, by:  Scott Wilkes (Scottywilkes) Quote hilighted text Edit Post Delete Post Print Post   View Post/Check IP (Moderator/Admin Only) Move Post (Moderator/Admin Only)

yeah i reset the ECU, u can do that via unhooking the battery for a while yeah? I had the battery out for about 20 mins while to get to some other bits. It hasnt effected the driving of the car at all, its just it dosnt go into choke when cold and is very rough at idling, dosnt stall though.

Im assuming the throttle position sensor is the black adjustable sensor opposite where the throttle cable pivots the throttle body plate?
Rob Rojo
Goo Roo
NSW
Soarer TT

Posts: 1112
Reg: 12-2007

Top of pagePrevious messageNext messageBottom of page Link to this message

Rating: N/A
Votes: 0 (Vote!)

Saturday, October 25, 2008 - 10:05 pm, by:  Rob Rojo (Rob_tt) Quote hilighted text Edit Post Delete Post Print Post   View Post/Check IP (Moderator/Admin Only) Move Post (Moderator/Admin Only)


Scott Wilkes wrote on Saturday, October 25, 2008 - 09:48 pm:

Im assuming the throttle position sensor is the black adjustable sensor opposite where the throttle cable pivots the throttle body plate?



Yes, thats the one.
Scott Wilkes
Tinkerer
Tasmania
TT

Posts: 21
Reg: 10-2008

Top of pagePrevious messageNext messageBottom of page Link to this message

Rating: N/A
Votes: 0 (Vote!)

Saturday, October 25, 2008 - 10:39 pm, by:  Scott Wilkes (Scottywilkes) Quote hilighted text Edit Post Delete Post Print Post   View Post/Check IP (Moderator/Admin Only) Move Post (Moderator/Admin Only)

thanks mate il check it out tomorrow. Where would i find the auto choke on it? I wouldnt mind checking that out to
Cihan Aday
Moderator
etuner.com.au
JZZ30

Posts: 2726
Reg: 07-2005

Top of pagePrevious messageNext messageBottom of page Link to this message

Rating: N/A
Votes: 0 (Vote!)

Sunday, October 26, 2008 - 11:10 am, by:  Cihan Aday (Cihan) Quote hilighted text Edit Post Delete Post Print Post   View Post/Check IP (Moderator/Admin Only) Move Post (Moderator/Admin Only)

Auto choke?

When the throttle position signal is registering that your foot is coming off the accelerator, the Idle Speed Controller (a stepper motor) opens an airway to the intake manifold (bypassing the throttle body) and is modulated by the ECU to maintain a steady idle.

To 'auto-choke', the ECU relies on the same principal but elevates engine RPM, pulls a few degrees ignition advance and enriches the fuel mixture.

To diagnose, you need to check the TPS resistance & output voltage (as mentioned) and disassemble then clean the ISCV (idle speed control valve). A lot of the time the cause is related to these items, but on the odd occasion it resides within the ECU itself.

Goodluck!
Scott Wilkes
Tinkerer
Tasmania
TT

Posts: 22
Reg: 10-2008

Top of pagePrevious messageNext messageBottom of page Link to this message

Rating: N/A
Votes: 0 (Vote!)

Sunday, October 26, 2008 - 11:55 am, by:  Scott Wilkes (Scottywilkes) Quote hilighted text Edit Post Delete Post Print Post   View Post/Check IP (Moderator/Admin Only) Move Post (Moderator/Admin Only)

yeah ive taken the ISCV out and cleaned it out, it was quite clean, sprayed it out with carby cleaner, and it came out rather clean, did that, blew it out and reinstalled it, but that didnt help, ive got the TPS out now,

Would u be able to tell me how to check output voltage? Im guessing it has to be hooked up to do that otherwise there wouldnt be any input voltage HAHA.

Also anyone got the specs of resitance at part, full and idle positions. Or is there a guide on here anywhere? Thanks

Add Your Message Here
Eye Candy
Click for full size
Bold text Italics Underline Center Text Upload photo from your hard drive Make a List Make a Table Make an Image Thumbnail Create a hyperlink Insert a clipart image Formatting Help
         

Username: Important Posting Information:
If asking a question, have you done a search to see if your question has already been answered?
Be aware that the use of SMS-speak eg "u" instead of "you" etc, will get your post deleted.
Password:
Enable HTML code in message
Automatically activate URLs in message

  Administration Administration      Log Out Log Out Previous Previous      Next Next