Fast Idle, '88 S4
11-01-2004, 05:31 PM
#1
Three Wheelin'
Thread Starter
Fast Idle, '88 S4
My '88 S4 seems to want to idle north of 1,000 rpms (~1100 on the tach, which may not be totally reliable, but it "sounds" too fast). Searches of previous threads indicate that the idle speed on an S4 is not adjustable, and I should be searching for a vacuum leak. Does the current group of observers concur? And absent a vacuum leak, do I then suspect the MAF or the LH? Is it true that there's no idle adjustment? I heard the same about my 944, which proved to be incorrect...
It shifts rather hard into reverse, which is my primary concern, although it probably leads to more heat than desired when stopped in traffic, too.
Thoughts and ramblings appreciated.
It shifts rather hard into reverse, which is my primary concern, although it probably leads to more heat than desired when stopped in traffic, too.
Thoughts and ramblings appreciated.
11-01-2004, 05:51 PM
#2
Range Master
Pepsie Lite
Lifetime Rennlist
Member
Pepsie Lite
Lifetime Rennlist
Member
Yes, look for a vacuum leak. Check the tension on your throttle cable just in case, but it still sounds like a vacuum leak.
11-01-2004, 07:03 PM
#3
Rennlist Member
Hi Brian,
Does your cruise work ? If not, this is a good clue there is a vac leak - albeit a bad one.....
The idle system is quite complicated, it is automatically set when the system works correctly, it is not adjustable. Another cause of the problem could be that the idle valve is stuck, search the archives on this one.
Does your cruise work ? If not, this is a good clue there is a vac leak - albeit a bad one.....
The idle system is quite complicated, it is automatically set when the system works correctly, it is not adjustable. Another cause of the problem could be that the idle valve is stuck, search the archives on this one.
11-01-2004, 09:20 PM
#5
Three Wheelin'
Thread Starter
Okay, so I disconnected the ground strap, and reconnected it. Car started and hunted/ran rough for a bit below 750 RPM or so, and gradually worked its way up to around 750, maybe a bit higher, on the tach. Then also disconnected the idle stabilizer vacuum line and squirted a ****load of lubricant (something for a bicycle chain, with Teflon) down it...currently soaking. And I adjusted the TB cable position just a wee bit slacker.
So the problem may be fixed, I should know in a half hour (someone posted 1-2 frosties worth of time, seems about right). Sounds like it's no fun if the idle stablizer poops out, the r/r of the manifold is a ~6 hour job?
So the problem may be fixed, I should know in a half hour (someone posted 1-2 frosties worth of time, seems about right). Sounds like it's no fun if the idle stablizer poops out, the r/r of the manifold is a ~6 hour job?
11-01-2004, 11:11 PM
#7
I remember encountering this problem a while ago. After some trial-and-error, I found that the cruise control cable was too tight. AS soon as I backed it off, the idle was perfect.