81 sc cis
 

Picked up a 79 SC with an 81 engine and lambda CIS.The wiring has been disconected from the air flow sensor,cold start valve,frequency valve,and throttle position sensor(Think thats what it is,a black plastic potentiometer attatched to the throttle valve)and temp switch on timing chain cover.The four disconnects on the rear of the engine are interchangeable,and colored green,blue,and two are black(Is there more?did I miss one?lol).Does anybody know what goes where?Thought the colors would match sensor colors,but no dice.The cold start and air flow sensor inlets are blue,the throttle sensor and frequency valve are black.Its in the car,and the disconnects are difficult to remove back there,and too many possible combinations to sort thru trial and error.Been searching this forum,and have Probsts book,but cant find a wiring diagram,or color photos to reference.

Chris

Wire connectors.........
 

Chris,

How to identify each:

AFS (air flow sensor)......this belongs to the engine wire harness with 2 brown wires.

CSV (cold start valve)...............this also belongs to the engine wire with 2 wires (yellow and red/black).

FV(frequency valve..............this belongs to the 12-pin connector wire harness at the back of the engine going to the ECU. It has two (2) wires both red/black.

TPS (throttle position switch)......this belongs also with the 12-pin wire harness and has three (wires). Look for these numbers: (9), (2), & (10) on the plug. Wires are blue/white (9), brown (2), and green/red (10).

Keep us posted.

Tony

Here is a picture Tony posted a few years ago. I am not sure if it's from his 78 or another SC engine he worked on. It's not an 81 or later.

I remember that the lengths of the wires help dictate where they go but Tony's method is foolproof if you can determine the wire colors.

I also have detailed pics of the rear of my 81 I can post this evening.

http://forums.pelicanparts.com/uploa...1386782430.jpg

Thank you Tony and Bob,the CIS is new to me.Was searching under cis lambda wiring diagrams and got zilch,then searched using cis lambda wiring and hit paydirt.Found some relevent threads,and noticed that both you gentelman are a great resource for the CIS noob.Used an inspection camera to trace the wire origins,and think i got it....Had a PDF of FSW,but am now unable to access it and Probst book doesnt mention input voltage to the sensors.Is there avoltage differential between the engine harness and ECU harness?Assuming the ECU to be in the mV range,and was wondering if probing the connectors for voltage would be definitive?Gonna give a go and I will post my findings.Dont want to peel back the insulation at this point,but you gotta do what you gotta do!When I drop this motor I now I know to only unhook the ECU-powered connectors!

I'll send the close up pics I have later tonight. Honestly, I remember when putting them back on (with the help of the pictures) that it was not confusing.

Picture taken from MCA photo library.......
 

Chris,

Look at the attached picture of an '82 SC's wire connections. You could see all four (4) plugs or connectors in question.

http://forums.pelicanparts.com/uploa...1386801021.jpg

AFS----------------Green plug
CSV----------------Blue plug
FV-----------------Black plug
TPS----------------Big black rectangular plug with 3 wires

The plug color are just guide and if for some reason you have a different color, go by the wire connected to the said plug. HTH.

Tony

That's what you need. Thanks, Tony.

Thanks for the shot of the 82 engine Tony,its gold.It looks so simple with engine out,I feel kinda lame posting this thread.when I turn the ignition on,I can hear the frequency valve humming,and I get a great spray pattern from a pulled injector when i lift the sensor arm,but get no spray during cranking.The fuel pump isnt kicking in either.Im charging the battery right now,give her another go when its charged up in an hour.I feel the problem must be electrical due to no fuel pressure while cranking.What should my next diagnostic be?The fuel pump works in the ignition on position,and lifting the sensor plate arm.Could the problem be in the sensor plate//fuel distributor?

The AFS connector is a safety switch for the fuel pump, it enables the pump during cranking. The TTS and CSV are also powered during cranking only.
Sounds like the AFS isn't connected, check below the CDI for a white T connector and make sure it is plugged in. The brown/red wire in that connector is the wire going to the AFS. It should be grounded when the ignition is off and the plate is at rest.
HTH

Dennis

Bob,does your 81 pressure control regulator have two ports(one one top,about 12mm,and one on the side,3mm for vacuum/or venting?was reading that lambda WURS dont have vacuum outlets.Are these for venting?Or do I have the wrong WUR?Part number is 0 438 140 089.Looking through Jim Williams' cross reference and the part number he lists is 090 105 108.Is this a replacement part number?The engine install was done by the PO.The history is shaky.No engine replacement was mentioned by PO,but the reciepts show 10k engine rebuild 70k miles ago,no mention of an 1981 engine and CIS lambda being installed in the 79 chassis anywhere in 100 or so service record reciepts.

Thanks for the help,
Chris

Chris, What type of engine do you have? Euro or US? Engine case number is near the oil pressure sender on the flat part below the engine serial number. 930/10 Euro, 930/16 US
Engine serial number will work too... (engine serial number is on the right side of the fan housing)
I'm thinking an 089 WUR is for a euro engine.

Confirmed.....WUR specs2

Good read here:
http://forums.pelicanparts.com/porsche-911-technical-forum/756338-81-911sc-cis-lambda-mia.html

Dennis,I looked through Probsts book and cant find the definition of CDI(Capacitve Discharge Ignition?) .I want to check that T connector out!

Identify your engine........
 

Chris,

What type engine do you have? USA or Row model. If your engine is using the lambda system then you should have a USA spec with WUR-090. A RoW car would not need a lambda unit with WUR-089.

WUR-089 is vacuum assisted.
WUR-090 is non vac assisted.

Whenever I do an engine start-up for the first time specially for an engine with unknown history, I check the following:
a). Ignition timing, sparks, and valve timing.
b). That the fuel system is delivering the correct fuel pressures (control and system).
c). FP test: Ignition switch @ ON position, FP relay removed, 87a-30 jumpered with in-line fuse.
Or Ignition switch @ ON position, FP relay installed, and lifting the AFS plate. In both cases, the FV would be activated too.
d). Check the cold control fuel pressures versus time at 30 sec. intervals till it stabilized to WCP (warm control pressure).
e). Do an air/vacuum test.

With these above info, You could more or less tell if the engine will start or not without even running the engine unless you have a serious air leak in the system. In other words, if everything is close to spec, there's no reason why it won't run. I could lend you one WUR-090 for your start-up. PM me.

Tony

Sorry Chris,
CDI is the Bosch unit for your ignition mounted at the rear fuse panel.
White T connector is right below the CDI unit in this picture of my car.
http://forums.pelicanparts.com/uploa...1386819434.jpg



Tony has stated what I was eluding to, if your engine and CIS is a Euro (or ROW) version the Lambda is not used... I was wondering if someone put the wrong engine harness on a ROW engine or just the wrong WUR on a US engine. Or, a combination of both...It makes a difference...

my engine is a 930-16,81 us spec.Kinda funny,the owners manual inside the glove box was for an 81sc,chassis was made in late 78.I dont know the extent of the update...there is ecu under the drivers seat,with two relays,unmounted,laying on the floor.In regards to Tony,i have completed a fused switch to jump the fuel pump relay.was hunting around tonight for fittings to bridge between the WUR and fuel distributor to measure fuel pressure and struck out.Im hooking up the fuel pump switch and going to measure fuel delivery and pressure/control pressure throughflow tonight.Tomorrow I can get to Mcfadden-Dale for the for fittings and a three way stopcock for my fuel pressure gauge.Thanks Dennis for the WUR link,looks like my WUR is supposed to have a vacuum port,maybe its the correct one.Wont find out until i pressure test tomorrow.And thanks for clarification on the CDI/White T connector.There is no white T connector,just the incoming and outgoing wire bundles.Im going to try and post photos(never done it,ANOTHER learning experience!)

Thank you all for your help!!

My game plan_
1-jump fuel pump relay,measure fuel quantities and post.
2-Check ecu for part number,pin count,and wire colors/pin positions.
3-Check fuel pressures when I get my fuel pressure gauge adapters.
4-Hunt around for that mia white T connector
Also wondering if back probing the sensors in situ will help with CIS?Was the only way I could I could diagnose my OBD 1 on my Jeep...

Chris

Jumped pin 30 to pin 67a,and fuel pump powered up.Removed fuel return line to the fuel tank,pulled the electrical plug off the WUR, and recieved a healthy amount of gas,appx 250cc in 15 sec.Will get exact flow rate in the morning.Need to probe the AFS connector during cranking when I get a helper!

Chris

Have some part numbers...
Air flow meter-0438 120 149
Fuel distributor-0438-100-077-78989 846
Throttle body-930 110 24815
Aux air reg- 0280 140 218

Thanks for sharing the knowledge!
Chris

Oops Dennis my bad.Reread your post, and yes i do have the euro 089 WUR.Thanks for the info,am wondering what else doesnt have a correct part number!

Chris

Some more info-The heads and intake runners are small port(34mm)and the air box has the CSV tubing.Im pretty sure the engine is a USA model

Chris