New guy here! Need help with my 82 SC

[bradc]

Greeting everyone, I've been looking around here for a while, but have never posted. I picked up a 1982 911 SC yesterday in Virginia, looks great, seems to run pretty well. The first thing I want to get sorted(first of many I'm sure) is the idle. Once you start her up in the morning the idle will raise to about 1500rpm, ill let her sit for 5 minutes or so, then off to work I go. From that point on any time I come to a stop or push in the clutch, she wants to idle up near 2700rpm! Just a little high for my standards. Anyway if you shut the car off, then immeadiately turn it back on, there is no difference, still 2800 rpm. Now once I get to the office, I can let her sit for say 15 minutes, go back up and start her up and she idles perfect @ 950 rpm? Its weird? Doesnt matter if I drive her 5 minutes or 30 minutes on the initial drive the idle is always 2800rpm, but once she sits without running for 15 minutes shes fine. I have taken the oil cap off once she idles down and the motor does stumple, so does this mean vac lines are good. Also I have heard some mention of Warm up regulators?

The only mod that I know of is an H&K muffler? Here is a pic, and thanks for the help!!

[LUFTMAN]

check to see if the aux air regulator on no. 5 cyl. intake tube is working. just disconnect the black square 2 wire plug on inside of valve careful of breaking the brittle and hard to get to plug heat makes the plug get brittle over time. there is a tiny spring wire (lock) ring around the base of the plug. if you can get that spring wire off it will help with a tiny 90 degree pick tool. then take a voltmeter or a test light and see if you have 12volt power and ground -with car running if ok take a ohmmeter and see if you have 26 ohms on terminals of disconected aux air regulator unit testing internal coil winding of aux. air regulator. start there this is a problem part if not the problem then check to see if the additional air valve works that is the round valve on the pass. side of engine that has a vacum hose connected to center of the valve with engine racing(2800 rpm) pull the vacum hose off that valve and see if car returns to idle speed(950 rpm) if it does problem with air valve you can plug vacum hose with a golf tee and drive. good luck hope that helps you out. try the second check first it is eaiser regards tom

[Grady Clay]

bradc,
Welcome to Pelican, you will find a lot of help here
Very nice 911, welcome to the joy of Porsche ownership.
Drive carefully.

First, is there any relationship between operating the clutch and the idle?

High, variable idle can be one or more of several things.
A vacuum leak, something amiss with the Warm-Up Regulator (WUR), something amiss with the Auxiliary Air Regulator (AAR) per Tom's advice and other.
Clearly it is temperature sensitive.

Modify your start-up and driving:
Shift to neutral.
Start the car.
Let the clutch out.
Put on your seat belt.
Immediately drive off.
Give full throttle but keep the revs below about 4000 until you have oil temperature.
Once warm, find some excuse to give full throttle and pull (preferably uphill) to 6000 at least once.

The purposes are to let the engine & transmission oil circulate while you put on your belt.
Second is to get the engine warmed up as fast as possible after starting.
The engine doesn’t warm-up well sitting at idle.
The engine likes some full throttle pulls to keep things clean (and the catalytic converter functioning).

(Yes officer, it is part of maintaining my emissions system. )

See if this changes your high-idle issue (probably not).


With the engine at whatever idle, grab the air filter assembly and move it about with reasonable force.
Does the idle change (up or down)?

Again, WELCOME.

Best,
Grady

[bradc]

Thanks for the responses guys, I'll try to work on her this afternoon and let you know the results, hopefully good!

[Vin-barrett]

Lots of possibilities but the first I would rule out is the decel valve.
Its the brass flying saucer on the passenger side of the engine bay.
Common on SC's for high idle.
Poor quality cell phone pic shows it's hose removed and plugged with a bolt. Try this to see if the high idle goes away, only takes a minute to do.

[don gilbert]

I agree with vinny, check the decel vavle first. They are known to stick causing high idle. (as is the aar) tap on them while the idle is high and see what happens.

[bradc]

Ok so I unplugged the vac. hose on the decel valve, idle went from 2800 to about 2000, still very high, but definately lower. Again if you drive car from a cold start, whether its 5 minute drive or 30 minute drive, still idles high, but if you turn it off and comeback in 15 minutes or longer, it idles perfect! What is the aar and where is it at? Also near the flying saucer deal is a valve that looks like a Warm up Relay, passenger side, looks new, I know this is not the WUR, but it looks new? All help greatly appreciated, thanks again!!

[Brandon-FL]

Originally Posted by Grady Clay

(Yes officer, it is part of maintaining my emissions system. )

I need to remember this one next time I get pulled over.

Welcome and I love the look of the car. When you get your idle issue straightened out let us know some more about the car, history, plans, etc.

[bradc]

Originally Posted by Brandon-FL

I need to remember this one next time I get pulled over.

Welcome and I love the look of the car. When you get your idle issue straightened out let us know some more about the car, history, plans, etc.

I wish she idled as good as she looks!! Hopefully get her straightened out soon?

[bradc]

Here is a picture of the golf tee fix on the decel valve, this helped a little but still idles above 2200rpm


This is a picture of the valve looking thing(not sure what this is, passenger side) anyway it looks new


This looks like a charcoal canister?(sorry not familiar with Porsches!) is there supposed to be a hose connected here? A/C has been taken off, not sure if that affects it?

[bradc]

I hit the new looking valve in the second picture with a hammer and the idle came down to 1500rpm. Should I just carry a BFH with me everywhere I go?

[Kemo]

always carry a bfh...always.

[Kemo]

actually...im more concerned about that green wire hangin there.

[whiteSC]

Brad,

Congrats on the nice ride. There's a good intro on the FI system used in your car at :

CIS Primer for the Porsche 911

Troubleshooting, component identification and lots of useful stuff. I found out about it right here on Pelican by the way, where there are a lot of knowledgeable folks who are willing to help out.

Best of luck,
Jeff

[Vin-barrett]

Originally Posted by Kemo

actually...im more concerned about that green wire hangin there.

no biggie, just from the A/C compressor which looks like it's been removed

[bradc]

I assume the valve the silver looking valve I hit with the hammer is the AAR? is that correct? Thanks for the link by the way, it says the AAr is not closing if the idle is too high after warmup. If the previous mentioned valve is the AAR, it s look like someone has just replaced it.

[brads911sc]

The AAR for the 80-83 SC is NLA. Hopefully you can repair the one you have. Could post a WTB ad and buy a used one.. Perhaps its defective...

[Gunter]

bradc, easy with the hammer, AAR may not get power or?
Try this easy DIY AAR check hot and cold:

Check the AAR located on the right side of the engine between 5-6 intake runner.
It's the item that has a small electric plug and a large vacuum hose connected to it.
Open the clamp holding the outside-hose.
Pry it off with the screwdriver just enough to get it out of the way so you can see into the opening.
Don’t worry about the Alu pipe; it’ll move enough.
With the help of a small mirror and a light, peek inside the AAR.
When COLD, you should see an opening in the slide shaped like a half-moon.
Re-connect the hose, start the engine and let it get real hot.
Stop engine, remove the vac hose again, check the opening again.
When HOT, the opening should be completely closed.
If it isn't closed, the AAR is either kaput, out of adjustment or doesn't get any power.
You can spray some WD-40 into the valve in case it is just sticky.
To check the power, carefully open the tiny clip on the plug with a very small screwdriver and pull it off.
The wire clip is tricky but necessary; don't yank it off.
Start the engine and check the plug for 12 V. (Careful of the fan/belt!)
Just ignition ON will not get power to AAR or WUR; engine has to run.
(One wire is power, the other (brown) is ground)
With power to the AAR, it should close after about 5 minutes.
If all is well, replace the hose and clamp securely.
Let us know if the AAR works HOT and COLD.

[kodioneill]

A Porsche service bulletin from the 80's recommended the removal of the round brass colored valve ( photos in previous post ) placing a socket around the nipple and squeezing it in a vice and compressing it 1-2 mm. I never tried it, but I believe it was to help reduce the high idle condition.

[Gunter]

Originally Posted by kodioneill

A Porsche service bulletin from the 80's recommended the removal of the round brass colored valve ( photos in previous post ) placing a socket around the nipple and squeezing it in a vice and compressing it 1-2 mm. I never tried it, but I believe it was to help reduce the high idle condition.

That's for the AAV but, once done, cannot be reversed.

I'd check the AAR first to eliminate malfunction and then check the AAV for proper function. The Bosch CIS is reliable and works fine if all components are good.

When people go away from stock and make changes, it becomes a guessing-game.