Hunting Idle
04-16-2006, 05:08 PM
#1
Rennlist Member
Thread Starter
Hunting Idle
The idle on my 86 951 tends to hunt a little once it's warmed up. Not bad, but you can hear the rpms hunt about 10-20 rpms randomly. It's always done this, but it just recently started bugging me (when I heard another 951 with a baby smooth idle). 
When I jumper the diagnostic port, the hunting stops.
When I remove the diagnostic port jumper, but disconnect the O2 sensor connector, the idle hunts again.
So, I figure that means the Idle Stabilizer is causing the hunt. Agreed? If so, I guess I'll try spraying carb cleaner in it to loosen the gunk, unless someone has a better approach. Thanks.
When I jumper the diagnostic port, the hunting stops.
When I remove the diagnostic port jumper, but disconnect the O2 sensor connector, the idle hunts again.
So, I figure that means the Idle Stabilizer is causing the hunt. Agreed? If so, I guess I'll try spraying carb cleaner in it to loosen the gunk, unless someone has a better approach. Thanks.
04-16-2006, 07:05 PM
#2
Burning Brakes
Join Date: Feb 2002
Location: Edmonton
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Tom, did you check your idle air screw to make sure it is in and in the right position. On my car I had a bit of idle hunt and when I checked the idle air screw I believe it was way loose. When I reset it the hunting idle went away.
Just a thought. Also check the hose connection under the throttle body.
Dan
Just a thought. Also check the hose connection under the throttle body.
Dan
04-17-2006, 10:01 AM
#3
Drifting
Definitely sounds like the idle stabilizer valve is bad. I tried to clean mine w/ no effect. Since mine is a track car (and rarely sees cold starts and doesn't have AC) I just removed the valve and capped the openings on the intake. I have to give it a little gas when starting cold but no other issues.
You could always just leave the port jumpered assuming you don't have any cold start issues.
You could always just leave the port jumpered assuming you don't have any cold start issues.
04-17-2006, 12:14 PM
#4
Rennlist Member
Thread Starter
Yes, check idle screw to set base idle.
I'll try cleaning it and see if it helps. I think I lose my O2 sensor feedback if I leave it jumpered though.
I'll try cleaning it and see if it helps. I think I lose my O2 sensor feedback if I leave it jumpered though.
07-11-2006, 01:23 AM
#7
Rennlist Member
Thread Starter
Yes, I sorted it out. First, I replaced the ISV with a spare one I happen to have sitting around -- after hosing out the inside with carb cleaner. That helped some. Then, and more importantly, I pulled out the Huntley MAF, injectors, and ARC2 and replaced it with Vitesse's MAF, Chip Board, Piggyback, and injectors. Problem solved.
