280ZX (S130) Forums Dedicated to 79-83 ZCars

'83 Zx turbo: Hot idle problem

Thread Tools
 
Search this Thread
 
Old 12-13-2011, 10:59 AM
  #1  
mjz
Registered User
Thread Starter
 
mjz's Avatar
 
Join Date: Dec 2011
Posts: 9
'83 Zx turbo: Hot idle problem

I have an '83 ZXT that idle's normally with the ACC vacuum line capped.
If I re-connect the vacuum line to the ACC valve, the car almost stalls.

Any thoughts on the problem? The ACC valve seems fine (works normally).

When the engine is cold, the idle is good even if the vacuum line is connected, only as the engine warms does the problem materialize.
mjz is offline  
Old 12-14-2011, 08:46 AM
  #2  
The Good Twin
 
NismoPick's Avatar
 
Join Date: Aug 2005
Location: Wild Wild West, UTAH!
Posts: 20,639
Welcome to ZDriver!

Are you connecting the vacuum line to the intake manifold or to the EGR / AAC actuator pump under the AFM?
NismoPick is offline  
Old 12-14-2011, 10:14 AM
  #3  
mjz
Registered User
Thread Starter
 
mjz's Avatar
 
Join Date: Dec 2011
Posts: 9
Originally Posted by NismoPick
Welcome to ZDriver!

Are you connecting the vacuum line to the intake manifold or to the EGR / AAC actuator pump under the AFM?

The vacuum line is factory connection. The AAC line connects to the actuator pump (V.C.M) near the AFM. Right now it is disconnected and unplugged. I don't believe there is anything wrong with the AAC since the car idles just fine not connected. If I connect the vacuum line, the idle drops to almost stall (i.e. the AAC is actuating and letting in too much air).
mjz is offline  
Old 12-14-2011, 10:32 AM
  #4  
The Good Twin
 
NismoPick's Avatar
 
Join Date: Aug 2005
Location: Wild Wild West, UTAH!
Posts: 20,639
IIRC, the AAC default is open. If you are hooking up vacuum, it is closing it, limiting the air flow. The same problem occurs when you remove the AAC all together and use a block off plate.

Double check that all the vacuum lines are run correctly, and that the EGR / AAC lines haven't been switched. Either way, if it runs fine disconnected, you can just leave it be.
NismoPick is offline  
Old 12-14-2011, 02:00 PM
  #5  
mjz
Registered User
Thread Starter
 
mjz's Avatar
 
Join Date: Dec 2011
Posts: 9
Originally Posted by NismoPick
IIRC, the AAC default is open. If you are hooking up vacuum, it is closing it, limiting the air flow. The same problem occurs when you remove the AAC all together and use a block off plate.

Double check that all the vacuum lines are run correctly, and that the EGR / AAC lines haven't been switched. Either way, if it runs fine disconnected, you can just leave it be.
What good is it - if it's not needed? (AAC blocked off).
mjz is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
dillenrocha
240Z, 260Z, 280Z Performance / Technical
2
08-21-2013 02:29 PM
Kremlar
300ZX (Z32) Forums
2
09-15-2011 05:20 AM
jooom
300ZX (Z32) Performance / Technical
1
08-06-2005 04:35 PM
mm107
300ZX (Z32) Performance / Technical
4
08-03-2005 06:43 PM
deckart
300ZX (Z32) Forums
3
11-27-2002 04:20 AM



Quick Reply: '83 Zx turbo: Hot idle problem



All times are GMT -7. The time now is 05:01 AM.