2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

Idle normal when cold, but high when warm

Thread Tools
 
Search this Thread
 
Old Jan 27, 2006 | 02:10 PM
  #1  
X-JaVeN-X's Avatar
Thread Starter
Drive.
Tenured Member 15 Years
 
Joined: Oct 2002
Posts: 1,676
Likes: 1
From: Washington, North Carolina
Idle normal when cold, but high when warm

Ok, I got tired of looking through idle problem threads. I couldn't find many that were having idle issues only after the car was warm. So anyway, when I first start the car in the morning, it goes to 700rpm and stays there (emissions and cold start assist removed) Anyway, once I pull through the gears once...the idle comes back down and settles at about 1500 rpms. Pretty darn sure it's not a vac leak. What else would cause it to have a normal idle at startup, but a high idle after the car is warm?
Reply
Old Jan 27, 2006 | 02:58 PM
  #2  
SureShot's Avatar
Seduced by the DARK SIDE
Tenured Member 15 Years
 
Joined: Apr 2001
Posts: 7,323
Likes: 2
From: Orange Park FL (near Jax)
If you have the thermo-wax & it's cold start fast idle cam, the cold start idle should start at 1500.
Then it should ease back as the coolant warms up.

My guess- The fast idle cam is not working at all and your throttle is sitting on the hard stop.
Then as the engine & oil warms up the internal friction goes down & the revs go up.

The rotary engine idle torque is so low that a cold stiff motor will stall without some help.

My car has no thermo-wax or fast idle cam or AWS, but I still have the BAC & the air bypass solenoid.

Last edited by SureShot; Jan 27, 2006 at 03:02 PM.
Reply
Old Jan 27, 2006 | 05:06 PM
  #3  
NZConvertible's Avatar
I'm a boost creep...
Tenured Member 05 Years
 
Joined: Jan 2002
Posts: 15,608
Likes: 8
From: Auckland, New Zealand
Originally Posted by X-JaVeN-X
What else would cause it to have a normal idle at startup, but a high idle after the car is warm?
Your cold idle isn't normal, it's supposed to be 900-1000rpm. That's what the thermowax is for. My guess is if you find out what's causing the high warm idle your cold idle will drop too, and it won't be able to idle without your help.

Did you remove all of the linkages associated with the thermowax? Not doing so can result in a high warm idle. Do you still have the BAC valve? If you do what happens if you unplug it? If you don't, and assuming you have no vac leaks, try winding the primary throttle stop screw out.
Reply
Old Jan 29, 2006 | 09:15 PM
  #4  
X-JaVeN-X's Avatar
Thread Starter
Drive.
Tenured Member 15 Years
 
Joined: Oct 2002
Posts: 1,676
Likes: 1
From: Washington, North Carolina
alright...the car is doing a little bit of a different idle now

it starts up at 700 and slowly rises to ~900-1000rpm, over about a 1 minute time frame. Then after it warms up, it idles at about 1300rpm. Gonna try the above things when I get a chance.
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
gxl90rx7
Haltech Forum
4
Sep 14, 2015 03:09 PM
rx7shirley
2nd Generation Specific (1986-1992)
6
Sep 2, 2015 02:11 PM




All times are GMT -5. The time now is 04:01 AM.