Stuck CSV or ???

[mattduncan]

greetings,

This will be long winded. I don't want to be rude, but if you are going to "guess" at the solution to my problem, please don't respond, I've dumped a lot of money into this problem and I'm about to rip out my %*&#$ hair...

To start, I have a 82 SC stock with MSD ignition ~145,000. On a scale of 1-10 on mechanics, I'm a 7. I've read most of the threads regarding "high idle" and "CSV" and "AAV, AAR", etc., with no specific answer seen. Some of the other unlucky people out there have a very similar problem and I haven't read a "resolution" that realy fixes the problem.

When cold, like frosty out cold, the car has difficutly starting. Starts on first crank, chugs like its going to backfire. If I give it gas it will. I installed a Pop-off valve to cover my butt just in case. I know the car so when it's cold I'll start it, let it chug for about 3 seconds, then kill the engine. Start it again and I'm at a nice "choked" idle. When starting warm, not a problem. The car runs all nice.... then....

When the car starts to "warm up" the idle will raise with the temp. Very, Very consistant. I just dumped money in to fix a "stall after deceleration" syndrom and at that time had the mixture adjusted. Talked to the mechanic and we agree the car is slowly becoming more "rich" as the temperature increases. When the car is still "cold" (around the first bar) and the idle is around ~900, the car runs very strong. Then, it slowly starts to get worse until the idle gets to about 1200 then it stops there. The car will eventualy run into the "red" on the temp guage if I'm not careful and I can feel a substantual power loss.

Soooo, before I invest an unknown amount of money into "hunt-and-peck" fix-it tactics, I thought I'd ask some pros. My questions are as follows:

1. What "parts" adjust the CO mix based on temperature?

2. Can a CSV get stuck and therefore run constantly rich?

3. I've recently replaced the O2 sens and had the wire re-ran (it got burned), how does the 02 sens actualy effect the CO mix?

4. Today I checked the AAV and AAR. According to the Haynes (I know it sucks, it's all I have) manual, by pulling and pluging different hoses and the idle changes this or that way, this or that is defective. According to the book, nothing is wrong. I don't trust it, what other test(s) can I do to the AAV, AAR to verify proper functionality?

5. I'm going to invest 2 more hours at a different shop on thursday to have them look at it. Should I point them in a certan direction or just let them have at it?

In retrospect, I really don't have the money to own, I mean maintain a Porche. I can't afford dumping much more into this and your help would/will be very helpful. My wife will kill me if I invest much more into my "baby"...

[Zeke]

I'm not going to guess at anything. I used to start my CIS car the same way when really cold. I think that it's an almost 'official' way to start these cars. So, that part might not need to be fixed.

[Jim Sims]

Until a pressure test rig is used to measure the CIS system pressures under the various starting and operating conditions even the "pro's" will be guessing. The cost of two hours of time at a reputable Porsche shop will pay for a CIS fuel injection manual (with a troubleshooting tree or list) and pressure test rig for the Bosch K-jetronic CIS fuel injection system. If you are a "7" you can use these to do your own troubleshooting and save significant amounts of money and frustration. There are several possible culprits for your problem in terms of components but to list them would be guessing . Cheers, Jim

[IROC]

JC Whitney used to sell these CIS pressure testing kits cheap. $40 or so and invaluable for troubleshooting these kinds of problems.

Mike

[tsuter]

1. WUR primarily but also Thermotime switch and AAR
2. Yes - but unlikley - you'd get smoke and black plugs
3. O2 sensor doesn't affect CO at cold start
4. 12V test and Oven bake test.
5. System pressure test and Control pressure test.

[vash]

not to be rude back to you, but you and your mechanic are going at it all wrong. hook up the above mention gauge, and find out what the problem is. oh yea, get a Bosch CIS book. i like the watson version, reads like a cookbook. my guess, is the Warm up reg. it totally controls your mixture depending on temp. by backfiring, you would be lean, so that would rule out the CSV leaking. get the gauge, hook it up, find out that you have a high cold control pressure, (greater than 2 bar @ 70 degree outside temps). start the car, find out what the warm control pressure is. piece of cake. save your hair pulling, get the gauge.

cliff

p.s. a few more hours at a 911 pro can get costly. save the money, do it yourself.

[mattduncan]

I've been searching around for info on the CIS and I found this...very quick helpful page for reference... I do believe that the diagram should say Aux air reg as aposed to aux air valve. Am I wrong...

CIS Cheat sheet

Thanks for all your input. The more I search, the more I'm thinking it's the AAR. I will test it tonight and replace some vacuum lines before taking it to the shop... I'm tosed on buying a Fuel pressure guage now, I really do think its "air" related. I may try the very scary carb cleaner test...I will post my results when I find them.

[konish]

Matt,
I honestly don't think your two problems are totally connected. Your cold start problem may indeed be your WUR. Mine was way out of spec and had to be adjusted. Can't remeber but is your car a Lambda car with a freq valve? Even after I adjusted my WUR, it still ran like crap. I tested the freq for resistance then cleaned all my connections to the freq valve and voila, it worked! Adjusted the mixture and the car starts like a champ in the morning (aside from the NORMAL 1/2 second stumble as the plate begins to rise).
1. Check and see if the dome lights work...if not replace the fuse. The circuit powers the freq valve relay.
2. If the lights work, check the relay. The car can be tuned to run without the freq valve but it'll never run right without it working.
3. Test your freq vlave connections for continuity and power. Test the freq valve coil...should be about 2 ohms of resistance (from memory)
4. Clean the (14 pin?) connector near the left hand rear shock tower behind the heater motor. (this is waht ultimately led to mine not working)

Your increasing warm idle isn't a sign of too rich...it's too lean. The AAV is open when cold and the fact that your car starts at all means that the CSV is working AND the AAV is working too. If it was stuck closed, it would be awful hard to start in the morning. As the heater comes on line, it closes the valve therefore STOPPING the controlled air leak (lean condition) into the system.
1. Pinch the AAV hose going into the airbox when the engine is warm and see if the idle drops. I know you said you did that, but that hose needs to be REALLY squeezed (like with a painr of needle nose pliers) in order to shut it for the test. The idle should drop.
2. Or, you can remove the AAV (between cyl 5&6) and put it in the freezer for an hour or so. It should be fully open. Then, hit it with a hair dryer and it should start to close. If it does not, then you have your answer.
3. Repalce the AAV if it isn't working

If your car's temp is going into the red, you may have ignition problems as well.

Please, please, please trust the guys who have gone through the CIS learning curve pain...BUY THE GAUGES. Really for $40 to buy the gauges and a cheap multimeter, you can diagnose 95% the problems you may have with CIS. There is NO way you can truly diagnose the problem without testing the control and system pressure. Seriously, you'll go crazy throwing money at the problem when the solution could be free! (well less the $40 :-) I hope you get this worked out, but truth be told I only got to the point where my car runs well after reading Probsts book on CIS, Haynes manual, and the Bentley so you do need to understand the basics before you begin. THe Probst book was purchased at Borders, so I know its immediately available....good too, I couldn't put it down and it still resides on my night stand much to my wifes chagrin.

R/
Dustin

[jdowty3]

Make sure your looking at the correct parts. I pulled and cleaned what I thought was the AAR, it was actually the Decel Valve. The AAR is hidden behind the Decel Valve and the air box. It's a MAJOR pain to get off, and probably 10 times harder to reinstall. I removed my Decel Valve and AAR and have not experienced any problems but my climate is significantly warmer. I plugged the open hoses for now but plan to replace the 2 triple Y hoses with a single hose from the The AAV is easier to remove if you have an allen wrench of the right length. If you remove the AAV hot, it should be closed and should open as it cools down. Mine worked but I cleaned it with carb spray and put some 3-in-1 oil on the valve disc.
good luck

[tsuter]

Here is a picture from our host of the AAR. Its in red, The AAV above it is not. You might even have two AAVs.

[mattduncan]

damn... all the aav aar info is conflicting... The picutre posted is what I belive (and my manual) sais is the AAR. I removed it in th past and it has a "disc" that rotates to allow air or restrict it. The thing above it, I can't locate on my car. I have something above my AAR that looks like that same type of diaphram but has only one small vacuum line on it (right in the center), not two big ones. According to my manual this is the AAV. I don't know what or where the decel valve is...

[konish]

right...tsuter is correct...my bad it is indeed the AAR

[jdowty3]

The item in red is the AAR, the other is the AAV. The one not in the above diagram that looks like an AAV with a small vacuum hose on the opposite side of the large hoses is the Decel Valve. You have to reach behind and to the left of the Decel Valve to feel the AAV. I had a problem with a sticking high idle when the motor was warm that was the Decel Valve not closing all the way.

[mattduncan]

ok, it's at the shop... Problem #1 found. (someone correct me if i'm wrong) The back voltage to the O2 sensor is intermittent from the Lambda unit. This is causing my mixture to flux from .5 to 2.5%!! I talked with the owner about "band-aiding" it by bypassing the O2 sensor. He wasn't keen on the idea but would run with it if the car will maintain proper mixture levels. Any thoughts? Also, how does one properly bypass the O2?

Prob #2. Minor vacuum leaks.. I can fix most of them by removing the Bonnet. No Prob...

[jdowty3]

Prob #1 - The easy way. I just unplugged mine.
Prob #2 - If you have a womans hat on your motor, you should remove it regardless any vacuum issues (sorry, the smart ass in me escapes occasionally). Is the Bonnett the same as the deck lid or the air box cover?

[mattduncan]

nope, not a womans head gear... the big black arched plastic on the very,very top of the engine just left of the fuel distributor and right of the throttle linkage...Comes of with two large "pipe clamps"... Also, i thought I read that one can't just unplug the O2 and expect things to work, it needs a Closed Circuit or something of that nature..??..

[jdowty3]

the big black plastic thing is the air box cover but removing it won't do anything about vacuum leaks. The leaks are on the other side of the air metering plate and the extra air throws off the amount of injected fuel so the car runs lean. The O2 sensor will try to adjust the lean condition but may not ba able to compensate completely. On a well tuned engine, the O2 sensor makes minute adjustments to keep the engine neither lean nor rich. My O2 sensor made the engine surge so I unplgged it. No more surging. Many people have disconnected their O2 sensors without ill effects, other than possibly less MPG.

[mattduncan]

Do you mean air filter cover?? that's not what i'm refering to. I mean this...



Behind this and below it are vacuum lines...

[echrisconnor]

This may be obvious, but be sure to fix your air/vacuum leaks before you have your mixture adjusted. Otherwise, you may fix something and whack it out again.

For the sake of common vernacular, the following resource I have found to be excellent for CIS help. All its teriminology is technically correct. You'll then be able to discern between an AAR and an AAV, etc.

http://members.rennlist.com/jimwms/CIS/CIShome.html

[jdowty3]

PET actually calls the part above, going from the fuel distributor metering plate to the throttle housing, the air box. I had always thought of the air filter housing and cover as the "air box".
"echrisconnor" is correct, the CIS primer he links to is great info.