Notices
Drivetrain Gearbox, Diffs & Driveshafts etc

Why does my tuned engine do this?

Thread Tools
 
Search this Thread
 
Old 29 January 2005, 05:11 PM
  #1  
911
Scooby Regular
Thread Starter
 
911's Avatar
 
Join Date: May 2004
Posts: 11,341
Likes: 0
Received 1 Like on 1 Post
Question Why does my tuned engine do this?

Just got my Sti v3 all built with TD05 20g and lots of parts to complement the turbo.
While I'm waiting for the engine to be mapped it is on the stock Sti V3 ecu.
When i start the engine the tickover climbs and climbs from 1000 to 2000 to 3000..... when I chicken out (cold engine) and switch it off.
The throttle cable is disconnected.

This seems like a pipe or sensor could be the reason, but anyone had this themselves?

911
Old 29 January 2005, 06:12 PM
  #2  
john banks
Scooby Regular
 
john banks's Avatar
 
Join Date: Nov 2000
Location: 32 cylinders and many cats
Posts: 18,658
Likes: 0
Received 1 Like on 1 Post
Default

Not had it myself, but with the throttle cable disconnected is the engine vacuum not pulling on half the throttle plate and opening it? But to be honest, I think you'd understand this phenomenon better than me with your nuts and bolts knowledge of engines that far surpasses mine...
Old 29 January 2005, 06:25 PM
  #3  
RON
Scooby Regular
 
RON's Avatar
 
Join Date: Sep 2000
Location: Deepest Darkest Dorset!!
Posts: 10,011
Likes: 0
Received 1 Like on 1 Post
Default

Get someone to hold the throttle shut just in case,........
Old 29 January 2005, 06:42 PM
  #4  
DeanF
Scooby Regular
iTrader: (1)
 
DeanF's Avatar
 
Join Date: Apr 2002
Posts: 2,808
Likes: 0
Received 0 Likes on 0 Posts
Default

I've had it , but not on a scoob, Both times has been air related, Vacum hose Etc off the inlet, Liike Ron says , lock the throttle linkage shut, then you know it's not that, Difficult to hear on a noisy scoob, but listen for sucking sounds

Dean
Old 29 January 2005, 07:48 PM
  #5  
P20SPD
Drag it!
iTrader: (1)
 
P20SPD's Avatar
 
Join Date: Jun 2002
Location: Flame grilled Wagon anyone?
Posts: 9,866
Likes: 0
Received 0 Likes on 0 Posts
Default

air leak
Old 29 January 2005, 11:25 PM
  #6  
911
Scooby Regular
Thread Starter
 
911's Avatar
 
Join Date: May 2004
Posts: 11,341
Likes: 0
Received 1 Like on 1 Post
Default

Thanks everyone, but you have the wrong impression of my skills John! (Meccano comes to mind)

The time it happened when I blipped the throttle using the quadrents on the throttle body, the tick-over started to race immediately after it returned to closed.

Air related it is, another bloody hose!

911
Old 30 January 2005, 02:40 PM
  #7  
RoRu
Scooby Regular
 
RoRu's Avatar
 
Join Date: Jan 2003
Location: The Rock
Posts: 1,350
Likes: 0
Received 1 Like on 1 Post
Default

I had the same problem recently, turns out i did'nt reseat the inlet manifold properly and air was leaking in, could be worth a look.
Old 30 January 2005, 05:11 PM
  #8  
911
Scooby Regular
Thread Starter
 
911's Avatar
 
Join Date: May 2004
Posts: 11,341
Likes: 0
Received 1 Like on 1 Post
Default

Ro, thanks for that.
The inlet was a pig to get back-on after fitting all the fuel hoses etc, just hope the Idle valve is the problem and not the manifold gaskets!
Do the simple things first...(that WILL be a first...)

Graham.
Old 30 January 2005, 08:32 PM
  #9  
vulnax999
Scooby Senior
Support Scoobynet!
iTrader: (7)
 
vulnax999's Avatar
 
Join Date: May 2003
Posts: 4,347
Received 8 Likes on 7 Posts
Default

Idle control valve likely , you did fiddle with the breathers off there... did you turn it around ( should be marked with white line/paint, ) ditto throttle position sensor etc.

Really could do with sorting before your mapping session.

Good project thread there anyway mate!
Old 30 January 2005, 08:38 PM
  #10  
911
Scooby Regular
Thread Starter
 
911's Avatar
 
Join Date: May 2004
Posts: 11,341
Likes: 0
Received 1 Like on 1 Post
Default

Think I've just done it.

Took it all apart, cleaned the inner valve slide valve with brake cleaner amd a 'micro' squirt of WD40, washed the rubber collar and the delicate valve and disc same way.
Screwed it all back together. Noticed the vac pipe from the FPR to the inlet manifold was barely sealed os used heat shrink to double the brass tube dia and the vac tube is a good tight fit.

Started the engine, revved it a bit while it warmed up and it holds a steady tick-over.

Think I'm ok now except the engine check light is still on. That's the next job tomorrow night.

Thanks for the thread comment, been good doing it all and the 'conversations' are very interesting.

Graham.
Old 30 January 2005, 09:23 PM
  #11  
RON
Scooby Regular
 
RON's Avatar
 
Join Date: Sep 2000
Location: Deepest Darkest Dorset!!
Posts: 10,011
Likes: 0
Received 1 Like on 1 Post
Default

Good o!!!!!
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
KAS35RSTI
Subaru
27
04 November 2021 07:12 PM
Mattybr5@MB Developments
Full Cars Breaking For Spares
28
28 December 2015 11:07 PM
Sam Witwicky
Engine Management and ECU Remapping
17
13 November 2015 10:49 AM
Brzoza
Engine Management and ECU Remapping
1
02 October 2015 05:26 PM
Ganz1983
Subaru
5
02 October 2015 09:22 AM



Quick Reply: Why does my tuned engine do this?



All times are GMT +1. The time now is 01:18 PM.