Too Fast Warm Up Idle!

[Vincent Hill]

I used the search engine and finally figured out that WUR was Warm Up Regulator and AAR Auxiliary Air Regulator (Maybe )

My engine idles at 2,500 at 25 to 35 degrees F and takes about 5 minutes to drop down then only to about 1800 to 2000 and 5 minutes later it will be 1200 to 1400 or a little lower for my NORMAL Idle of about 1000 to 1100.

Are there no EASY Adjustments for the Warm up REGULATOR or the or the "AAR"

It seems to me that on my 1976 I made some kind of adjustment on the AAR and I Thought there was some kind of Adjustment on the Warm Up Regulator!

[James Brown]

Vince, there easy to adjust IF you know what there doing and understand HOW to change it. you need some special tools, a CIS fuel pressure Gage set (assuming this is a CIS car) and you have to take apart these components that normally don't come apart. MAYBE you can tap on the WUR or decrease the amount of air that goes through the AAR but these are just temporary fixes. you need to read and understand how the CIS SYSTEM component works together, by adjusting one part, it effects another part.
Good news is that you can do it! now, what year car, engine, anything not stock?, millage and pictures! Oh, if you have the control pressure reading for that temp. would be helpful.
Do you have Wayne's books? a Bentley manual? there is a good CIS primer on this board somewhere that explains how the Bosch CIS works (required reading). That should be a good start for now. Tons of others will chime in and "walk you along the path of enlightenment"

[oneblueyedog]

Check your floor mat to see if it's bumping the accelerator pedal.

I imagine the AAV takes longer to close in the cold weather.

Oddly enough I was monkeying with my decel valve in warm weather and found that if it is set at the recommended vac pressure, it kept my idle up at about 2500 for far too long in the winter plus an occasional backfire. I did what many do and plugged the vac line on top going to the t. It made the idle drop to normal. So that meant that the decel valve kept the idle up with that extra air it gets from the AAV. I then connected a mighty vac to the top of the decel valve and pulled a vac to see when the engine revved up. Yep, at about 15 (fully warm). I then reset the decel valve until way past 20. It now falls gently at fully warm, but not a drastic drop to stall the car as when it was plugged.

Some people set them to keep the car revved up for a shift. Mine does that in bitter cold, but not when fully warm or in warm weather. We have had temps of mid 70's to upper 20's the last 2 weeks, so I'm constantly chasing CIS tune. 3mm wrench in the center console at all times.

Not sure what year your car is, but sounds like a 78-79.

[Paulporsche]

Pelican "Mystery Train" has a great thread on AAR adjustment and repair.

See Jim Williams' website for CIS info.

Make sure all ignition components are operating correctly, incl your distrib. Then check for vacuum leaks and check your fuel and control pressures to make sure they are within spec. Make sure your AF mixture is @ about 3.5% CO.

Make sure your sensor plate and plunger are moving freely and your airbox popoff valve is seating correctly.

Quite often high idle speeds are due to a vacuum leak @ the decel valve. You can plug the line to the top of it and see if there is a change.

Make sure your vacuum retard on the diz is operating correctly, or remove it altogether. And be sure your timing is correct.

You should have a warm idle speed of about 950. @ a 30F start your high idle should be about 2000 and go down to 950 by about 5 min.

[T77911S]

i take it you no longer have a 76???? you need to always post the year.

you dont want to go changing the WUR to change the idle or warm up times. the WUR has absolutley nothing to do with the AAR. although they both are used in cold startup, they do not effect one another. the WUR has specs it operates at, do not change it from that unless you really know what you are trying to achieve and know that changing CP's will get you there. the only change to the AAR that i have heard of is trying to change how fast it heats up which changes how long it holds the idle up.


15 is too low for a decel valve. it needs to be above 20. it should open with the higher vacuum from closing the throttle plate at high RPMS and not with idle vacuum.

[Vincent Hill]

I had my car information under my last profile, but when I had problems posting Pics I opened a new profile and Wayne moved everything over to this profile. I will fix this TODAY!

I have a 1982 911 SC with about 122,000 miles (It was a Garage Queen never driven if there was a possibility of Rain)

I have fuel Pressure Gauges that I made adapters to measure Everything when I had the 1976. Last Night I went out after seeing the results of the search engine about the AAR. I did find that the Hose on the outside was loose, so I took it off and cleaned it and the AAR with Brake Cleaner and pushed it back on and tightened it.

Second, I lowered the Idle which I had set about 1200 to make sure it ran clean for emissions to about 950 with the clutch out and lights and heat ON.

Today (About 25 degrees F) It star ted up at 2K went to 2.5K and in a minute or so was at 2Kand after blipping the throttle it was at 1800. In about 3 minutes. Please understand that this is about 800 RPMS LOWER than it was in less time. My wife left for work so I do not know how long it took to get to Regular Idle.

So at least this is Better and I remember either replacing the AAR or Adjusting where the Valve blade was to make the 76 run better. At least it is a lot closer to what it is supposed to be.

More Later and 100% thanks for the information so far.

[jmancool]

I find the idle in my 1979 SC starts at about 2000rpm but it doesn't drop for a long time. My drive to work is about 30 minutes and it may drop back to normal idle by the time I reach work but usually once I turn the car off and restart it the engine shortly after, the idle is normal at about 850 - 900 rpm. Anyone have any ideas?

[T77911S]

Originally Posted by jmancool

I find the idle in my 1979 SC starts at about 2000rpm but it doesn't drop for a long time. My drive to work is about 30 minutes and it may drop back to normal idle by the time I reach work but usually once I turn the car off and restart it the engine shortly after, the idle is normal at about 850 - 900 rpm. Anyone have any ideas?

its best to start your own thread. it can get confusing when others jump in and want help with their car- too many different conversations going on.

check for 12v to the aux air regulator (AAR). if that is good, try spraying some wd40 in it, it may be sticking or do a search here and rebuild it.

[Vincent Hill]

Several People have now said that I need to "Clean" the AAR with either Carb Cleaner or WD 40. I also remember that in the 1976 I had to make an adjustment so it was fully closed and esolved my problems there. I plan to remove it and Clean and adjust it (How ever I did it) and then I think It all will be fine. I AM glad to see that a Hing RPM is normal but that is 2K and not 3K. Lowering the hot idle went a long ways to getting this better. I also see a few Vacuum lines I need to replace. They are as hard as Plastic and break the same!

[Paulporsche]

Have you checked out Mystery Train's AAR thread?

Have you checked for a vac leak @ the decel valve?

[jmancool]

Thank Paul for the good advice, Mystery Train's AAR thread was excellant.