Warm up issue and access to AAR

[jedwards1123]

Hi all.
On start up, my 83 SC 3.0 starts perfectly, hunts for about 10 seconds then heads for around 1800 rpm where it stays for far too long. Even idles too high for too long when warmed up.
I understand that the AAR and AAV are the point to start but i cannot work out how to gain access to them without dropping the motor?
Any hints?

Also, I understand that the AAR controls the duration of the warmup and voltage supply is the first thing to test. Is that correct?

[Two Rivers]

You might look at the AAV valve to see if the spring that pulls the slider valve closed is broken. After it is off the car look at it and shake it and see if the slider moves back and forth. If it is you can drill the rivets and replace the spring from a hardware store and replace the rivets with the kind you peen over.

After the repair put 12 volts and ground to the pin connectors and time how long it takes to close.

The valve is not to hard to take off just have to take your time, I use a Allen wrench. 5MM if I remember right. Remove the air cleaner cover for more access.
The AC compressor will also have to be taken loose and layed over the right rear fender with a towel or something under it so as not to scratch the paint.

[T77911S]

that is the AAR, (regulator, not valve). it is located between runners 5 and 6. and easy check is for 12v on the connector. do the easy stuff first.

i would also check fuel pressures and mixture. oh, and check for 12v on the WUR.

if the idle eventually comes down, the AAR is getting hot fromt the engine and closeing, as it should.

[Two Rivers]

Your right AAR. I have called it a AAV for so long I know what I Mean to myself. There is a up dated AAR with different resistance in the heater from 33 to 26 ohms. As of May 82.

The AAR can also be adjusted by driving the cap plug exactly 0.5 mm in. Warning if the 0,5mm is exceeded you will have to rig a way to pull it back out or buy a new one. Most likely it will be damaged.

[Bob Kontak]

Originally Posted by Two Rivers

The AAR can also be adjusted by driving the cap plug exactly 0.5 mm in. Warning if the 0,5mm is exceeded you will have to rig a way to pull it back out or buy a new one. Most likely it will be damaged.

Interesting. Never knew this. Here is a more detailed description of the process.

Auxiliary Air Regulatory Adjustment

[boyt911sc]

Originally Posted by jedwards1123

Hi all.
On start up, my 83 SC 3.0 starts perfectly, hunts for about 10 seconds then heads for around 1800 rpm where it stays for far too long. Even idles too high for too long when warmed up.
I understand that the AAR and AAV are the point to start but i cannot work out how to gain access to them without dropping the motor?
Any hints?

Also, I understand that the AAR controls the duration of the warmup and voltage supply is the first thing to test. Is that correct?

Jeff,

You can remove both the AAR & AAV without dropping the engine. The AAR is easy to access but the AAV, needs some flexibility and ingenuity to remove it. A partial drop would help a lot.

How long does the 1800 rpm last? 'Too long' is relative. Give us more specific duration like 2 or 3 minutes. 'High' how much in measurable number? Keep us posted.

Tony

[jedwards1123]

Thanks for the input Tony and everyone else.
In terms of details, from stone cold with morning temps of around 15C, she revs go to around 1800 and stay up for around 4 to 5 minutes. As I live 10 minutes from work, having it rev its guts out for 1/2 the time I drive it, really reduces the driving pleasure.
Even when its 3/4's warmed up, (temp gauge out of the lower red sector) it revs to 1800 for 2 minutes or so, with no apparent need. In our climate, which rarely ever gets below 10C night or day, even in winter, 1 to 2 minutes should be more than enough to overcome cold cylinders.

My other thought is if its possible to disconnect the AAR without upsetting normal running, or would this introduce air flow and vacuum issues?

[T77911S]

check out the AAR first. 10 minutes with a MM can tell you a lot, or even a test light.

the AAV works off of vacuum, or lack of. with no vacuum, the AAV opens to assist in starting. once it is running, the vacuum should pull it closed.

[Gunter]

No need to remove the AAR for testing,
No need to do a partial drop,
But if you have A/C, the compressor is in the way.
Your choice of moving the compressor to make room.

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.

[boyt911sc]

Originally Posted by Gunter

No need to remove the AAR for testing,
No need to do a partial drop,
But if you have A/C, the compressor is in the way.
Your choice of moving the compressor to make room.

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.

Gunter,

You could test the AAR, WUR, or thermovalve (optional) in a CIS engine without the need of running the engine. All they need is power to terminal #30 (FP relay socket). When you perform a FP test (running the FP), both the WUR and AAR are energized!!!!

Connecting terminals 87a & 30 using a suitable jumper wire with in-line fuse will energized the following FP, WUR & AAR. A good AAR will be totally closed in 4 or 5 minutes or less by the electric heater alone. Running the engine to test the FP, WUR, & AAR is just another way of wasting fuel and totally unnecessary IMHO.

How is your new car (993)? I'm still looking for a good buy.

Tony

[Gunter]

Hey Tony,

993 and 911 always stored in Winter.

The reason why I don't recommend jumpering the pump relay for testing the AAR is that not all DIY's have the expertise or feel comfortable around electrical issues.

However, if someone is comfortable with the process to jumper 30 & 87a as explained in the Bentley SC Repair Manual page 201-5, go for it.

IMHO, simply starting the engine eliminates making up the fused jumper wire, etc.

Happy Ho-Ho.

[boyt911sc]

Originally Posted by Gunter

Hey Tony,

993 and 911 always stored in Winter.

The reason why I don't recommend jumpering the pump relay for testing the AAR is that not all DIY's have the expertise or feel comfortable around electrical issues.

However, if someone is comfortable with the process to jumper 30 & 87a as explained in the Bentley SC Repair Manual page 201-5, go for it.

IMHO, simply starting the engine eliminates making up the fused jumper wire, etc.

Happy Ho-Ho.

Gunter,

I agree with you. Many new CIS owners are not well familiar with some of the tricks we do and some have no reference manual like Bentley. I have taken it for granted. Thanks for the feedback.

Tony