Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   Pelican Parts Forums > Porsche Forums > 911 / 930 Turbo & Super Charging Forum


Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Certified User
 
billjam's Avatar
 
Join Date: Aug 2007
Location: Perth, Western Australia
Posts: 2,002
Garage
930 Electrical & Emissions Parts Locations

It has been driving me nuts trying to cross-reference items in the factory wiring diagrams, manuals and the emissions control system diagram AND actually identifying where they are physically located on the car.
What set me off on this course this time was another bout of electrical gremlins (yet to be diagnosed) and a dose of frustration with Porsche not being consistent with their part names.

Anyhow, I have made up a list of most of the engine electrical and emissions components and tried to fill in as many blanks as I could. I still have a few question marks to deal with, and I know that some items are in there twice (like temp sensors), but I'd love some assistance to finish this off.
In particular, can you help with the actual location of items on rows 6, 17, 18, 22, 24, 25, 31, 32.
PM, email or post any details that you can add to the list and I will update it and re-post. Feel free to add details of items I may have missed, or correct any mistakes.



It's not practical to load the wiring diagrams here for reference, but here is the Emission Control System diagram from the Owner's Handbook that is referred to in column F.


__________________
Bill
1988 Carrera - 3.6 engine (with ITBs, COPs, MS3X) and a whole set of turbo body panels waiting in the attic.
Day job ... www.sspowdercoat.com.au
Memories: '68 912, '72 911T, '80 911SC, '84 911, '85 930, '86 930, '87 911
Old 01-12-2012, 05:39 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)
Turbofrog
 
smurfbus's Avatar
 
Join Date: Aug 2009
Location: Europe
Posts: 1,510
IIRC the thermo time switch #7 they refer to is in the driver side cam chain cover. It has wires to the 7th injector to help cold starts.

Not sure what the other #31 temperature time switch is. There is a white wire at the driver side heat regulator box near the rear upper shock mount that looks like temp related.
__________________
************************************************** *******************************
79 930: HX40#18, MS3pro+ID1000+044+E85, Ignition: 123/TUNE/MSD6A, BB+2*turbosmart38, WMI.
Old 01-12-2012, 08:52 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)
Certified User
 
billjam's Avatar
 
Join Date: Aug 2007
Location: Perth, Western Australia
Posts: 2,002
Garage
Quote:
Originally Posted by smurfbus View Post
IIRC the thermo time switch #7 they refer to is in the driver side cam chain cover. It has wires to the 7th injector to help cold starts.

Not sure what the other #31 temperature time switch is. There is a white wire at the driver side heat regulator box near the rear upper shock mount that looks like temp related.
I think you meant "thermo time switch #10". Yes, it seems that rows 6, 15 and 31 are all the same item. Also, row 5 "cold start valve" is the 7th injector.
Thanks for those hints.

Item 32 which is called "throttle bypass valve" on the wiring diagram (at O46) really has me puzzled. It seems to be closely connected to the WUR. Anyone got any ideas on that one?
Also still looking for all the info for all the blanks.

List is updated in blue ...

__________________
Bill
1988 Carrera - 3.6 engine (with ITBs, COPs, MS3X) and a whole set of turbo body panels waiting in the attic.
Day job ... www.sspowdercoat.com.au
Memories: '68 912, '72 911T, '80 911SC, '84 911, '85 930, '86 930, '87 911
Old 01-13-2012, 12:38 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)
Turbofrog
 
smurfbus's Avatar
 
Join Date: Aug 2009
Location: Europe
Posts: 1,510
WUR and AAR have the same 12V from fuel pump relay and the AAR bypasses TB. It could be another term for AAR
__________________
************************************************** *******************************
79 930: HX40#18, MS3pro+ID1000+044+E85, Ignition: 123/TUNE/MSD6A, BB+2*turbosmart38, WMI.
Old 01-13-2012, 03:07 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #4 (permalink)
Turbofrog
 
smurfbus's Avatar
 
Join Date: Aug 2009
Location: Europe
Posts: 1,510
I bet this is the other thermovalve
930 oil tank ?
__________________
************************************************** *******************************
79 930: HX40#18, MS3pro+ID1000+044+E85, Ignition: 123/TUNE/MSD6A, BB+2*turbosmart38, WMI.
Old 01-16-2012, 07:06 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)
Certified User
 
billjam's Avatar
 
Join Date: Aug 2007
Location: Perth, Western Australia
Posts: 2,002
Garage
Quote:
Originally Posted by smurfbus View Post
WUR and AAR have the same 12V from fuel pump relay and the AAR bypasses TB. It could be another term for AAR
Hmmm, maybe the AAR (row 8) and the throttle by-pass valve (row 32) are the same animals. The manual also refers to the AAR as auxiliary air valve.
Anyone else??

Quote:
Originally Posted by smurfbus View Post
I bet this is the other thermovalve
930 oil tank ?
Yes, this is #38 on the Emission Controls diagram (row 14 in my list). It doesn't appear on wiring diagrams because it isn't electric.

I'm still looking for the physical locations of:
  • 35* temp switch - wiring diagram D49 (list row 17)
  • 15* temp switch - wiring diagram D49 (list row 18)
  • oxygen sensor power control relay - wiring diag E41 (list row 22)
  • retard control box (cat converter vacuum) - wiring diagram B49 (list row 24)
  • air valve (retard control box shift valve) - wiring diag B49 (list row 25)
__________________
Bill
1988 Carrera - 3.6 engine (with ITBs, COPs, MS3X) and a whole set of turbo body panels waiting in the attic.
Day job ... www.sspowdercoat.com.au
Memories: '68 912, '72 911T, '80 911SC, '84 911, '85 930, '86 930, '87 911
Old 01-16-2012, 09:29 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #6 (permalink)
 
Registered User
 
mark houghton's Avatar
 
Join Date: Jul 2008
Location: Central Washington State
Posts: 3,874
Quote:
Originally Posted by billjam View Post
Hmmm, maybe the AAR (row 8) and the throttle by-pass valve (row 32) are the same animals. The manual also refers to the AAR as auxiliary air valve.
Technically, the AAR is a regulator whereas the AAV is a valve. As a regulator, the AAR modulates the amount of air to affect cold idle. The AAV, on the other hand, is purely emissions related IIRC and is either open or closed as any good valve should be (I can't remember it's function, as the '87 models don't have one for some reason).
These are two different animals from what I can remember reading. The abbreviations get swapped all the time. Someone else out there knows more about the AAV than I.
__________________
Mark H. 1987 930, GP White, Wevo shifter, Borla exhaust, stock everything else. The result of a massive Pelicanite good will fire recovery effort. Truely an open book, ready for the slippery slopes to modification.
Old 01-17-2012, 05:10 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #7 (permalink)
Registered User
 
Join Date: Jul 2006
Location: S. Florida
Posts: 7,289
I'll take a shot at this... The different names you see for obsolete CIS hardware gets confusing sometimes and there is so much of it one eventually will go to amazingly simple and far superior EFI.

"I'm still looking for the physical locations of:
35* temp switch - wiring diagram D49 (list row 17)
15* temp switch - wiring diagram D49 (list row 18)
oxygen sensor power control relay - wiring diag E41 (list row 22)
retard control box (cat converter vacuum) - wiring diagram B49 (list row 24)
air valve (retard control box shift valve) - wiring diag B49 (list row 25)"

Can't say where the two "temp switches" are because I don't have the wiring diagram and don't know the temp specs of the ones on the car. There is a temp sensor on the breather cover next to the oil pressure idiot light switch and the temp sensor on the right side chain cover disables the lambda emission sytem until the oil temp warms up a certain amount so I'll guess it's those.

The oil temp sending unit for the dash gauge is next to the oil pressure gauge sending unit to the right of the fan housing.

The "oxygen sensor power control relay" is the black relay on the engine compartment relay panel.
There is a heater element in the lambda system oxygen sensor that heats it up and gets it working faster after a cold start and that relay controls power going to it.

I think the "air valve (retard control box shift valve)" is the vacuum solenoid #37 in the vacuum retard line that blocks vacuum retard from reaching the distributor for the first minute atfer a cold start so the idle speed is about 300 rpms higher and the motor is a little peppier after a cold start.
Remember that the mechanical thermovalve #38 is blocking vacuum advance to the distributor for a little while at the same time after a cold start to heat up the catalytic converter faster. If you only had vacuum retard during that first minute after a cold start the car would be sooo sluggish it would be ridiculous.

I still don't know what electrical timer and relay is controlling the vacuum solenoids #37 but I think that is the "retard control box (cat converter vacuum) - wiring diagram B49 (list row 24)"
Seems it has to be part of one of the relays under the driver seat or maybe the k-jetronic ECU under the driver seat controls it. I never bothered to trace the wire going to it and the other vacuum solenoid also labeled #37 in the above diagram that controls the air pump diverter or changeover valve and they're not on my car anymore anyway.

edit: Thought about this some more and it seems the temp sensor for controlling both vacuum solenoids #37 would have to have it's own heating element so it only works the first time you start the car while the oil is still cool. The only temp sensor on the car with a built in heater element is the thermo time switch for the cold start injector and it's mounted in the left side chain case cover.
At the same time, the enrichment relay that disables the lambda system into open lop mode is mounted in between the speed relay and the k-jetronic ECU under the driver seat and it uses the oil temp sensor in the right side shain case cover and the throttle position switch on the throttle body so maybe that temp sensor is also tied into the speed relay and controlling dwell time of both vacuum solenoids labeled #37.

When I took the aluminum cover off my speed relay to see whats in there I saw two small relays on the circuit board. The speed relay is the factory rev limiter so it has to count ignition events over a short time period to accomplish that and why would the rev limiter need two small relays inside? I'm not an electrical engineer nor do I have a wiring diagram so all I can do is guess.

With that in mind I'll guess one of the small relays inside the speed relay controls the dwell time of both vacuum solenoid change over valves labeled #37 in the above diagram. There are alot of wires going to the speed relay and these two vacuum changeover solenoid valves are mounted next to each other on the left side of the origonal blow off recirculation manifold and wired in parallel so they both change over or divert intake manifold vacuum at the same time but to different emission control devices.

Last edited by JFairman; 01-17-2012 at 02:45 PM..
Old 01-17-2012, 07:52 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #8 (permalink)
Certified User
 
billjam's Avatar
 
Join Date: Aug 2007
Location: Perth, Western Australia
Posts: 2,002
Garage
"I'll take a shot at this... The different names you see for obsolete CIS hardware gets confusing sometimes and there is so much of it one eventually will go to amazingly simple and far superior EFI."
"Confusing" is being kind! Thanks for your input. I agree, EFI is looking good - I am currently doing a Megasquirt and ITB conversion on my spare 3.6.

As far as "temp switches" go, I know where they are all physically located, it's just that I can't be sure which ones are which. I have sussed out some of them, but the wiring diagram shows two that I can't figure (rows 17 & 18). I am fairly sure that one of these will be the sensor in RH chain housing. In the wiring diagram, 17 has green/yellow wire and 18 has blue/green wire so I might have a look on my car tonight and see if wires are visible.


"The "oxygen sensor power control relay" is the black relay on the engine compartment relay panel."
I don't seem to have one of those (row 22). At the rear relay panel, I do have a black round relay that is the airflow sensor charging pressure relay (row 28). The wiring diagram shows both of these, but I seem to have only the second one installed.


"I think the "air valve (retard control box shift valve)" is the vacuum solenoid #37"
Makes sense; cross that one off.


"edit: Thought about this some more and it seems the temp sensor for controlling both vacuum solenoids #37 would have to have it's own heating element so it only works the first time you start the car while the oil is still cool. The only temp sensor on the car with a built in heater element is the thermo time switch for the cold start injector and it's mounted in the left side chain case cover."
I don't think that is correct. Problem is that the wires running from that temp sensor (row 6) only go to the cold start injector, so there is no connection to the vacuum solenoids.


"When I took the aluminum cover off my speed relay to see whats in there I saw two small relays on the circuit board. The speed relay is the factory rev limiter so it has to count ignition events over a short time period to accomplish that and why would the rev limiter need two small relays inside? I'm not an electrical engineer nor do I have a wiring diagram so all I can do is guess."
I know its not much use without the rest of the diagram, but it looks like this.



"... these two vacuum changeover solenoid valves are mounted next to each other on the left side of the original blow off recirculation manifold and wired in parallel so they both change over or divert intake manifold vacuum at the same time but to different emission control devices."
They have a direct connection to pin 7 at the Fuel Enrichment Control Unit (under seat). That in turn is connected to Speed Relay and K-Jetronic unit.


I have filled in a few more gaps, but still unclear about Throttle Bypass Valve (row 32). Can someone confirm that this is also known as AAR (row 8)?


__________________
Bill
1988 Carrera - 3.6 engine (with ITBs, COPs, MS3X) and a whole set of turbo body panels waiting in the attic.
Day job ... www.sspowdercoat.com.au
Memories: '68 912, '72 911T, '80 911SC, '84 911, '85 930, '86 930, '87 911
Old 01-17-2012, 11:10 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #9 (permalink)
Registered User
 
Join Date: Jul 2006
Location: S. Florida
Posts: 7,289
"I have filled in a few more gaps, but still unclear about Throttle Bypass Valve (row 32). Can someone confirm that this is also known as AAR (row 8)?"

Technically there are only 2 throttle bypass valves on 930 CIS: The cold start AAR that bypasses air around the throttle body to raise idle speed when the motor is cold, and the deceleration valve which bypasses air around the throttle body butterfly during decleration and intake manifold vacuum is higher than 20 inches of mercury. It is sometimes referred to as a vacuum limiter.

The AAR has a 12 volt heater element on it's bimetalic spring just like the WUR and they are wired in parallel and mounted next to each other. It is the one in the electrical diagram you posted and you can see it's heater element wired in parallel with the WUR heater element in the diagram.
The 12v power to them comes from the rear fuel pump relay so if the rear fuel pump is running they are heating up.

The decleration valve is opened only by intake manifold vacuum and it bypasses some air around the throttle body when the butterfly is closed during higher rpm deceleration and intake manifold vacuum raises above 20-21 inches of mercury. It is closed at idle speed when working properly and manifold vacuum is only around 11-13 inches of mercury in a 930. Idle speed vacuum is alot lower than normally aspirated motors because the low 7:1 compression ratio which is very inefficiant when the motor has to suck in it's own air.

The deceleration valve is an emmision control device that lowers NO2 and hydrocarbon exhaust emissions during deceleration and it works at the same time the blow off valve operates and it opens at a little higher intake manifold vacuum than the blow off valve when working properly.
It also reduces turbo compressor surge in tandem with the blow off valve during deceleration to a small degree.

Your '86 930 came with a yellow relay onb the rear panel. They all did in the eightee's or at least all the USA cars did.
If it's gone somebody removed it and stuck a black relay in it's socket. My '87 won't run with a black or red relay in place of the yellow relay but one will work there in some of the older cars so I don't know whats happening with yours.

All USA 930's from '86 on are lambda equipped with an air pump and catalytic converter and they all have a black relay on the rear panel to supply 12 volts to the heater element in the lambda oxygen sensor. If it's not there it's been removed on your car or maybe you're mistaking one for the other.
The empty relay socket that only has female 2 pins and is mounted sideways on the back of the relay panel is for connectiong an oscilliscope type meter to check the lambda pulse valve frequency/dwell time.

hope that helps.
Old 01-18-2012, 06:14 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #10 (permalink)
Registerd 930 user nut
 
DeFreest's Avatar
 
Join Date: Apr 2012
Location: NH
Posts: 256
Garage
Thumbs up O2 wideband sensor in existing hole ok?

So if I understand this correctly you dont really need the oxygen sensor for the 87 930 engine and that if I installed a wideband air/fuel guage in my car that the bung that the narrow oxygen sensor is in would be a good place to install my new wideband O2 sensor saving me some welding? Also the fuel head for a stock 87 930 engine will still work without any mods for a stock engine?
Old 05-07-2012, 06:17 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #11 (permalink)
Certified User
 
billjam's Avatar
 
Join Date: Aug 2007
Location: Perth, Western Australia
Posts: 2,002
Garage
Quote:
Originally Posted by DeFreest View Post
So if I understand this correctly you dont really need the oxygen sensor for the 87 930 engine and that if I installed a wideband air/fuel guage in my car that the bung that the narrow oxygen sensor is in would be a good place to install my new wideband O2 sensor saving me some welding? Also the fuel head for a stock 87 930 engine will still work without any mods for a stock engine?
That's a "yes" on all counts.

__________________
Bill
1988 Carrera - 3.6 engine (with ITBs, COPs, MS3X) and a whole set of turbo body panels waiting in the attic.
Day job ... www.sspowdercoat.com.au
Memories: '68 912, '72 911T, '80 911SC, '84 911, '85 930, '86 930, '87 911
Old 05-07-2012, 08:47 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #12 (permalink)
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 11:42 PM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2020 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.