CIS component part numbers, help me figure out what I have!

[wiggle_puppy]

Hello all,

I have a 1982 911SC that I bought with no documentation as a project. The car was very stripped out for track use and I'm slowly making if more drive-able. I installed an AEM wideband oxygen sensor on my left exhaust bank (the car is running headers and an M&K 2-2 muffler) to monitor the fuel mixture while driving. I found that the car runs VERY rich while idling (10:1 or so) and VERY lean while accelerating (15-17:1). Last year I fixed the air box cracks, cleaned the injectors (by myself using the wire trick), cleaned all CIS parts, replaced injector sleeves, replaced all gaskets (and intake tubes), and adjusted the valves. This year I'd like to get the car running "okay."

I absolutely plan on testing the pressures and everything but first I wanted to make sense of what I have. Since I have a 1982 car my CIS should be lambda controlled but the oxygen sensor, lambda ECU, and all wiring was removed prior to my ownership. Even more interesting is that it seems I have a '78/79 fuel distributor.

Part....................Number
Fuel distributor.....0 438 100 031
WUR...................163, 085, 060 (I see three numbers on this part and I'm not sure
..........................which are relevant
Intake runners......ending in 2R (small port, as expected)

I do not have a frequency valve and I believe this should be correct given the fact that I'm running a pre-lambda fuel head. Both the AAR and deceleration valve have been removed (though I do have those parts to reinstall).

There are two blue plugs behind the throttle, one for the cold start injector, the other for what might be the WOT switch.

So this looks like I'm running an early big-port CIS setup on a later 2R small port motor, not sure if this matters.

My next step is to verify pressures and wiring, but can you help me determine if my fuel distributor and WUR are matched?

Thanks!

[gomezoneill]

I can't help much but I can tell you the blue plugs (don't know why they're not different ) are for the cold start valve and the other is for the fuel pump switch located in the air cleaner/fuel distributor sensor plate housing.

[HarryD]

Visit this web site: 911 CIS Primer - Index

Should help.

[boyt911sc]

The numbers you posted were the wrong numbers. They are not the Bosch ID numbers. It should be a 10-digit number like this 0-438-140-xxx format. Look on top of the WUR or by the base of the post (if you have one). The FD-031 is for '78-'79 SC US spec. with 38-mm ID intake runners (4R). Do you know the number for the AAR? How about the AFM (air flow meter)? Thanks.

Tony

[wiggle_puppy]

Sorry for dropping off the face of the earth, I just got back home after some work travel. So I think I know what the problem is: my WUR is incorrect. In fact, my entire CIS system is just a hodge-podge of BS. I initially said that the WUR had the number "060" on it but I believe I was reading that upside down - this makes it a "090" WUR from a 1981-1983 car. The WUR has two vacuum connections, one on the top which is connected to the fuel distributor, and one out the side which is connected to the throttle body before the throttle plate.

Furthermore my car does NOT have a frequency valve (neat, right) and I assume this was removed when the oxygen sensor and related equipment was removed. The AAR numbers are 0 280 140 218 which means that I have a later AAR.

So my CIS is thus:

No lambda system, "backdated" fuel distributor, small port runners, and the "correct" 1982 AAR and WUR. I'm pretty screwed, huh?

At this point I think I'm going to order a Tbitz kit and wash my hands of this as setting the system right would require a boatload of parts: airbox, lambda system, frequency valve, and likely more. It makes me sick to think this but the car was just butchered at some point in the past.

[gazzerr]

That's really not unusual. Mine had all the right parts but some were disabled or plugged. Amazing what gets done to these cars. People looking for cheap fixes I guess.

[wiggle_puppy]

Plugging some of the hoses seems pretty common if it means that you're removing the AAV or the deceleration valve but eliminating the frequency valve from the system entirely is just madness (unless you also install an older WUR and AAV). I'm just really, really mad right now both at myself for buying the car without more care and at whoever did this to the CIS system in the first place and thought that it was a good idea. I installed my AEM wideband to help get my engine dialed in and now I've found that it's essentially impossible unless I spend $1000+ on a bevy of new CIS parts or convert to EFI.

I guess once I'm running Triumph ITBs and Megasquirt I'll be pretty damn happy but I was not planning on buying those parts this year AND I'm not going to be able to drive the car to my track day in June as a result.

[Walt Fricke]

The '78-79s worked pretty well without the Lambda system if you don't care about optimizing MPG and emissions to the 81-3 standards. The Lambda doesn't really contribute to performance, though if your system has it you'd best use it for the FV, though no need for the O2 sensor for performance - the default plus the three position throttle switch takes care of richening the idle and WOT valve frequency, and leaning part throttle some (which doesn't reduce track/AX performance).

I agree that often changes here are somewhat uneducated hack jobs - the three valves on the air supply side may not add much to track performance, but as long as they work they don't detract either, and keeping a basically stock system in spec is easier than trying to match what you have mixed.

The Euro 81-3 SCs did not have the Lambda system, so a FD and WUR from one should make your motor run fine. Yes, those Euros had 9.8 CR, not 9.3, but so what - mixture is easily enough adjusted.

[gazzerr]

I wouldn't beat yourself up too much. The parts are old and all the rubber seals, resistance coils and internal diaphrams and airbox (and O2 sensor) on mine were pretty much shot or leaked like crazy. Even the mounts on the system were so bad it had sagged and the cis was laying right on top of the engine shroud.

It would have needed a refurb anyway. I had to go through everything. Most of the parts are not that hard to find or rebuildable and there's a fantastic community on here keeping it going.

ITB's would be very cool if you have the cash to drop on it.

[boyt911sc]

Originally Posted by wiggle_puppy

Sorry for dropping off the face of the earth, I just got back home after some work travel. So I think I know what the problem is: my WUR is incorrect. In fact, my entire CIS system is just a hodge-podge of BS. I initially said that the WUR had the number "060" on it but I believe I was reading that upside down - this makes it a "090" WUR from a 1981-1983 car. The WUR has two vacuum connections, one on the top which is connected to the fuel distributor, and one out the side which is connected to the throttle body before the throttle plate.

Furthermore my car does NOT have a frequency valve (neat, right) and I assume this was removed when the oxygen sensor and related equipment was removed. The AAR numbers are 0 280 140 218 which means that I have a later AAR.

So my CIS is thus:

No lambda system, "backdated" fuel distributor, small port runners, and the "correct" 1982 AAR and WUR. I'm pretty screwed, huh?

At this point I think I'm going to order a Tbitz kit and wash my hands of this as setting the system right would require a boatload of parts: airbox, lambda system, frequency valve, and likely more. It makes me sick to think this but the car was just butchered at some point in the past.

Wiggle,

You have mistakenly identified your WUR as -090. The Bosch 0-438-140-090 (WUR) for '81~'83 SC US models is non-vacuum assisted and has no vacuum port at the side of the WUR. Take a picture of your WUR and will help you identify it. And you probably have an ignition distributor with advance and retard vac lines. You could make your 'late SC' engine run as a '78~'79 SC by using the correct CIS components and combinatioin.

You have the FD-031 already. So look for a vacuum assisted WUR like -045, -069, or -089. Then a decel valve and TTS (thermotime valve) on your shopping list. What ignition distributor do you have on the motor now?

Could you start and drive the car at the moment? If it does, the conversion would be a very easy (piece of cake). If it does not run at all, find someone to help you. If you are having difficulties now identifying your CIS components, testing and evaluating them would be a lot more challenging.

Tony

[wreckah]

i've been down this route before...looking for NLA CIS parts, second hand WUR's, benchtesting all these old components...the money flies out the door.
i bit the bullet and went for tbitz system, could not be happier. The car runs like a dream, and as a bonus: proper fueling means safety/longetivity, much better throttle response, and much quicker.

If you want to return this car to stock, including the lambda system with frequency valve ...be prepared to read hours, days, months, and still get nowhere. Very complicated setup.

[wiggle_puppy]

Originally Posted by boyt911sc

You have mistakenly identified your WUR as -090. The Bosch 0-438-140-090 (WUR) for '81~'83 SC US models is non-vacuum assisted and has no vacuum port at the side of the WUR. Take a picture of your WUR and will help you identify it.

Hi Tony,

Thanks for the offer. I have mistakenly told you that I had a vacuum port off the side of my WUR and I'm not sure why that was stuck in my brain. I definitely have the correct 090 WUR with a vacuum port on top (connected to the throttle before the butterfly), and a hose that connects to the fuel distributor.

I have a later style distributor with vacuum advance and retard but the vacuum retard is capped. The AAV has a four wire connector attached to it and two of the wires are cut...

Here are some pictures that will show this (sorry the WUR photo is out of focus but you can see the connections...it definitely says "090" next to the 0-438-140 stamping. You can also see a picture that shows that I don't have a frequency valve.










Keen eyes will see that the last photo shows two vacuum caps on throttle body connections which are completely borked. This is an older photo and those vacuum leaks have been rectified. This cleaned it up a little bit as the car now only leans out to 15:1 when accelerating rather than 17+:1. You can also see a healthy slathering of JB Weld as the airbox was split along the seams on the entire perimeter when I removed it last year. The car starts incredibly easily when cold (almost immediately after turning the key), idles high (1500 or so), then slowly knocks the idle down to 800-1000 or so. The car is a bit more difficult to start when warm as I have to crank it for 2-3 seconds before it will actually catch and sputter to life. The car even starts when it's 20 degrees outside and runs very well during those times.

[boyt911sc]

Originally Posted by wreckah

i've been down this route before...looking for NLA CIS parts, second hand WUR's, benchtesting all these old components...the money flies out the door.
i bit the bullet and went for tbitz system, could not be happier. The car runs like a dream, and as a bonus: proper fueling means safety/longetivity, much better throttle response, and much quicker.

If you want to return this car to stock, including the lambda system with frequency valve ...be prepared to read hours, days, months, and still get nowhere. Very complicated setup.

Jan,

I completely agree with you that an EFI system is more modern and efficient system than the CIS (Ketronic). But I completely disagree with you that CIS troubleshooting is very complicated. Aside from the ECU, there is no electronic involve in CIS troubleshooting. Basically it involves mechanical and electrical work only. No software or lap top needed to tune it.

The lack of basic understanding or knowledge is the basic difference between a frustrated troubleshooter and a successful one. There is no substitute for hands-on experience, the more you spend time doing things the better your skill is developed and enhanced.

The problem with the wrong CSV mount could have been detected much earlier if you were more serious and interested in finding the culprit/s rather than disposing the whole CIS unit. You may not like the CIS system because of your bad experience, but CIS troubleshooting is simple and easy if you know what your are doing. I have not encountered a CIS problem that you or any typical DIY'er could not diagnose or fix using simple tools. All my (special) tools were basically fabricated from stock materials obtained from local hardware stores like Home Depot or Lowe's.

Believe me, I want to build an EFI engine too. But my lack of computer skill is setting me back. Someday, I might try it or a 930 CIS.

Tony

[wiggle_puppy]

I've seen some very nicely done CIS cars and I would absolutely be inclined to stick to the system if my car was anywhere near original and/or the system wasn't so hacked. After having the system apart last year (I wish I had compared the part numbers then...) I was very impressed by the simple elegance (maybe not the right word) of the system. It's really an impressive piece of engineering and can be wonderful in good tune.

[boyt911sc]

Originally Posted by wiggle_puppy

I've seen some very nicely done CIS cars and I would absolutely be inclined to stick to the system if my car was anywhere near original and/or the system wasn't so hacked. After having the system apart last year (I wish I had compared the part numbers then...) I was very impressed by the simple elegance (maybe not the right word) of the system. It's really an impressive piece of engineering and can be wonderful in good tune.

wiggle,

For a decade ('80~'90), Bosch Ketronic (CIS) was the most popular automotive system world-wide. It was used by Porsche, MB, Ferrari, Volvo, BMW, Saab, Bentley, etc. until the introduction of EFI. There's no question EFI is better and more efficient than CIS. The biggest problem with CIS today is the diminishing numbers of experienced or trained technicians or mechanics. Most of these experienced mechanics are getting old and retiring. The new generations of technicians today are not familiar with this antiquated technology.

Tony