idle stabilizer
#1
Racer
Thread Starter
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
I have a few gremlins on my 86 951. A few minutes after a cold start the car will lump/hunt at a slightly lower idle speed. I did the idle speed adjustment via clarks-garage, a while a jump/bypass the idle valve under the test ports the idle is correct, unhook the wire and it lumps around again. My questions is , can you bypass this valve, or must it be replaced?
#2
UAE Rennlist Ambassador
Rennlist Member
Rennlist Member
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
You can bypass the valve, but the car would idle very low when cold and when the ac is on.
Better to replace it, Ian at 944online sell rebult units for ~US$80 or so.
Click Here
Better to replace it, Ian at 944online sell rebult units for ~US$80 or so.
Click Here
#5
Banned
Join Date: Feb 2004
Location: In self-imposed exile.
Posts: 14,072
Likes: 0
Received 8 Likes
on
7 Posts
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Oop, yea just checked. . . I'd still get a new one though. . . Seems like an awful lot of people have been having problems with these lately so perhaps they're reaching the end of their useful lives. I actually have a used one to swap into my 951 but I'm not holding my breath that it will work (already tried one - worked fine for a month then same problem). If it doesn't work or ends up dying as well, I'm goin' with a new one.
#6
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
A lot of times these valves tend to get stuck mechanically, while still being electrically sound. Try using a lubricant on the valve like PB Blaster, WD-40, etc. Make sure that it won't freeze since it is getting colder out.
#7
Drifting
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Originally Posted by Melchior
A lot of times these valves tend to get stuck mechanically, while still being electrically sound.
Trending Topics
#9
Addict
Rennlist Member
Rennlist Member
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
I say just ditch it. Mine was bad an I capped off the ports for a year before I got around to buying a new one. A week after installing the new one I took it off again, I just like how the car feels much better without it. For what it's worth, I drove the car almost daily though a winter in Pittsburgh without any problems, just take it easy while the car is cold, which you should be doing anyway.
#10
Racer
Thread Starter
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Just verifying, are you removing the hose from the stabilzer to the intake and the hose from stabilizer to the interecooler tube? Do you have to jump or modify the ISV wire plug/harness? Anything I am forgetting?
#11
Nordschleife Master
Join Date: Aug 2003
Location: Los Angeles
Posts: 9,558
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
I bypassed mine, and can barely notice its gone. Not replacing it. Pull the hose of the intercooler pipe, cap that, pull the other hose off the intake manifold, cap that, unplug the plug and let it sit there, so need to jump it as far as i know.
~Eyal
~Eyal
#12
Drifting
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Originally Posted by mjensen
Could you guys explain how you are bypassing the ISV?
#13
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
digging up an old thread here. I was messing with my ISV and tried the electronic bypass method. I was wondering when the electronic bypass jumper is in place for setting the idle, it puts the valve in its center position, but does the center position still let air pass through? I find that if I clamp off the hose completely so air can pass through at all I get a different idle then if I just do the electronic bypass to set the idle. ................I was thinking that if the center position of the isv closes the valve off that clamping off the hose to the idle stabilizer would be ideal for setting the idle since no air would be allowed through, which works fine. but then when I unclamp the hose my idle is too high. Making me think the ISV is letting too much air through or the isv lets a percentage of air through all the time even at its center position. does anyone know?
#14
Addict
Rennlist Member
Rennlist
Small Business Partner
Rennlist Member
Rennlist
Small Business Partner
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
The ISV at center position is, essentially, half-open.
However, when using the electronic bypass, the ISV isn't set to 50%, it is set to (roughly) 9% open.
Clamping the ISV hose, and then setting the idle is not going to yield good results... The system expects that there is a specific amount of bypass air (thus the 9% open), and uses that for all its ISV control.
However, when using the electronic bypass, the ISV isn't set to 50%, it is set to (roughly) 9% open.
Clamping the ISV hose, and then setting the idle is not going to yield good results... The system expects that there is a specific amount of bypass air (thus the 9% open), and uses that for all its ISV control.
#15
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
The ISV at center position is, essentially, half-open.
However, when using the electronic bypass, the ISV isn't set to 50%, it is set to (roughly) 9% open.
Clamping the ISV hose, and then setting the idle is not going to yield good results... The system expects that there is a specific amount of bypass air (thus the 9% open), and uses that for all its ISV control.
However, when using the electronic bypass, the ISV isn't set to 50%, it is set to (roughly) 9% open.
Clamping the ISV hose, and then setting the idle is not going to yield good results... The system expects that there is a specific amount of bypass air (thus the 9% open), and uses that for all its ISV control.
Again logger install coming soon.