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

Cold start rough idle : \

Thread Tools
 
Search this Thread
 
Old 10-06-2007 | 10:43 PM
  #1  
thetremendousti's Avatar
Thread Starter
w0rld's l0ngest m0t0rswap
 
Joined: Sep 2007
Posts: 676
From: Torrance, CA
Cold start rough idle : \

In my '81 ZX N/A whenever i cold start it, it maintains a rough idle until driven up and down the block a few times or on the freeway. Why is this, could this be timing? How do i check the timing, would it be easier to buy a "timing light" and a haynes or to just take it to "pierre'z" in hawthorne?
Old 10-06-2007 | 10:56 PM
  #2  
NismoPick's Avatar
The Good Twin
 
Joined: Aug 2005
Posts: 20,639
From: Wild Wild West, UTAH!
Classic cold start valve and/or air regulator problem. SEARCH for "cold start" and you will find your answer.
Old 10-07-2007 | 10:12 AM
  #3  
duowing's Avatar
NisTuner
 
Joined: Sep 2005
Posts: 2,800
From: Cleveland, Ohio
It could also be related to the Cylinder Head Temp Sensor. My car though would idle alright, it was just that it would pop, sputter, and just really be hard to drive when cold. Oh when it's cold and idling weird does it run fine otherwise?
Old 10-07-2007 | 06:28 PM
  #4  
thetremendousti's Avatar
Thread Starter
w0rld's l0ngest m0t0rswap
 
Joined: Sep 2007
Posts: 676
From: Torrance, CA
yeah it runs fine, it just coughs and sputters once or twice when you cold start it. otherwise as long as it's warm it's good to go.
Old 10-08-2007 | 12:16 AM
  #5  
duowing's Avatar
NisTuner
 
Joined: Sep 2005
Posts: 2,800
From: Cleveland, Ohio
My bet is on the air regulator.
Old 11-04-2007 | 11:05 PM
  #6  
thetremendousti's Avatar
Thread Starter
w0rld's l0ngest m0t0rswap
 
Joined: Sep 2007
Posts: 676
From: Torrance, CA
well today i cleaned out the AFM and everything in it was surprisingly very clean, and i adjusted the carbon contacts so they're "fresh" just a bunch of orange stuff in the box, looked like rust or soemthing....odd....but that's all that was in there, and the idle is still wierd, it is 500 when i start cold and warming up to about 800 so what's going on here?! Yes, i know i'm asking this in 2 different places but the other thread isn't coming up as recently posted....
Old 11-05-2007 | 12:54 PM
  #7  
NismoPick's Avatar
The Good Twin
 
Joined: Aug 2005
Posts: 20,639
From: Wild Wild West, UTAH!
Did you ever check the cold start and air regulator???

Originally Posted by NismoPick
Classic cold start valve and/or air regulator problem. SEARCH for "cold start" and you will find your answer.
Old 11-05-2007 | 09:13 PM
  #8  
duckyz's Avatar
Registered User
 
Joined: Jun 2002
Posts: 903
From: Alameda, CA
Geez....let's start at the beginning.

What's your air filter look like?

Start at the easiest thing and go from there. My Z doesn't like the transition from summer to winter, but I have things pretty dialed in and all I usually need to do is adjust the idle screw.
Old 11-05-2007 | 09:20 PM
  #9  
thetremendousti's Avatar
Thread Starter
w0rld's l0ngest m0t0rswap
 
Joined: Sep 2007
Posts: 676
From: Torrance, CA
yeah filter's fine, but i REALLY don't know what to do about the idle! I REALLY had to crank it this morning to get it started and it died a few times, then sputtered, its getting worse sounds like. Cold start valve you think?
Old 11-06-2007 | 07:44 AM
  #10  
NismoPick's Avatar
The Good Twin
 
Joined: Aug 2005
Posts: 20,639
From: Wild Wild West, UTAH!
Originally Posted by thetremendousti
Cold start valve you think?
For the third time....

Originally Posted by NismoPick
Classic cold start valve and/or air regulator problem. SEARCH for "cold start" and you will find your answer.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
bongpogi
280ZX Performance / Technical
3
08-19-2015 12:15 PM
vgterian94
300ZX (Z31) Forums
3
07-29-2014 08:58 PM
mrdark
280ZX (S130) Forums
7
10-26-2012 05:31 PM
Jory
300ZX (Z31) Performance / Technical
5
10-23-2012 08:40 AM
zed head
300ZX (Z32) Forums
15
07-10-2010 02:42 AM




All times are GMT -7. The time now is 08:50 PM.