Mystery Silver Relay (what does it do?)

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KINGJOHN808
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Mystery Silver Relay (what does it do?)

Post by KINGJOHN808 »

Aloha all,

Finally figured out my “no start problem”. Turned out to be the CPS and the Speed Sensor. Both when tested had 1100ohms and had cracked connectors. When I removed them the wiring was hard and brittle so pretty sure these are original parts.

Also (would love to blame gremlins but I’m pretty sure I did this); during the process of cleaning the contacts on relays about 3 months ago, mixed a 4 prong and a 5 prong relay putting them in the wrong locations. Was driving me crazy! Checked and changed the coil, used a NOID light to check the input to the injectors, charged the battery, was just about to change out the ECM, then decided to check and reseat the relays. Sure enough, I noticed that I had some how mixed them up. Put them in the correct places and BOOM, car started right up. HOO HOO!

Any Hoo, on to why I’m requesting some help. I have a copy of the ETM but have a silver relay that I can’t account for. I’ve figured out the fuel pump relay, main relay and the purge valve relay but this silver 4 prong (rectangle) relay has no markings at all. Not even a wiring diagram etched or printed on it.

It appears the car will start and run without it but still want to know what the purpose is. I’m going to clearly label all my relays it would have save me several hours trouble shooting. I also have a connector that has 12vdc at all time that is not connected to anything. The ETM says there should be a diode attached and that it goes to the purge valve but there is already a diode attached to something else. Am I missing the diode and is it needed?

Please take a look at the picture, it’s the box circled in red, it’s 4 prong and I can see the wiring and colors but it doesn’t match the ETM, nor does the ETM show 4 relays attached to the main fuse box.

Mahalo’z in advance for the assistance.
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Ewa Kai, Hawai’i
1984 633CSi
1983 633CSi (wreckers)

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hornhospital
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Re: Mystery Silver Relay (what does it do?)

Post by hornhospital »

Have you tried the wipers with that relay pulled? It reminds me of the wiper/delay relay in an E30.

Edit: but I see you have a wiper/delay relay already, lower left in the shot of your fuse/relay box.
Ken Kanne
'84 633CSi "Sylvia"; '85 635CSi "Katja";'85 325e "Hazel Ann"; '95 M3 "Ashlyn"
KINGJOHN808
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Re: Mystery Silver Relay (what does it do?)

Post by KINGJOHN808 »

Yep, it’s strange. Checking the ETM, I thought it was the fuel purge relay but the wire colors are different. Car starts and runs without it so I’ve got to be missing some other function somewhere.

Gonna keep looking. Don’t want to cut open the wire loom to trace as I’m afraid that I might “introduce” a issue into the electrical system.
Ewa Kai, Hawai’i
1984 633CSi
1983 633CSi (wreckers)

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Utern
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Re: Mystery Silver Relay (what does it do?)

Post by Utern »

I also have that rectangular relay on my (12/81) 633 csi
I had been looking for more info when I came across this post. I would like to find that actual recall letter but haven't yet

http://bigcoupe.com/phpBB2/viewtopic.ph ... 90&#p73669

Ignition Upgrade for Idle Improvements - "Gene M." <MClan>

Your 1982-1984 U.S. model 633 (also applies to 533 and 733) may have had an upgrade performed by the dealer to address idle problems. Technical Service Bulletin TSB 13 07 86 (1162) discuss these changes.
The major components of the upgrade were to:

(1) Replace the ignition system (coil, cap, rotor, wires) with the 30 kv components (the type in the 635) and adding a rotor adapter;

(2) Install a 35 degree C thermotime switch;

(3) Replace the idle control unit with the green unit (or may be a black unit with green tape);

(4) Install a purge control module;

(5) install an external resistor in the wire for the Coolant Temperature Sensor that feeds the Motronics (should be the one with the light gray connector):
For Motronics Control Units with a Bosch code date of 341 and lower (9/81-9/83 production dates), Resistor type is a 560 ohm, 1/2 watt "Gold Band" metal film resistor .

For Motronics Control Units with a Bosch code date of 342 or higher (production date after 9/83), Resistor type is 270 ohm, 1/2 watt, "Gold Band" metal film resistor
____

This upgrade was performed at no charge, but may not have been done on your vehicle. If you have the slip on rotor instead of the bolt on type, the full upgrade was not done, but you may still have had the external resistor installed under TSB 11 11 84 (920), which was only added to address a complaint of "hesitation/poor throttle response" during several minutes of operation after starting a cold or warm engine at an ambient temp above 75 degrees F.
__________
1982 633csi
Utern
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Re: Mystery Silver Relay (what does it do?)

Post by Utern »

Here is the TSB that covers the mystery Relay

GROUP 13 Fuel Systems
Bulletin Number 13 07 86 (1162) Page 1 of 6
Montvale, NJ May 1986 Technical Dept.
SUBJECT: Engine Campaign Procedure and Idle Control System Modification


MODEL: 533i, 633CSi, 733i (1982-1984 Model Year)

Condition: Idle speed fluctuates. Rough idle. Idle dips below specification on deceleration.
Cause: Idle system components incorrectly calibrated and/or Engine systems not latest configuration.
Correction: Perform Engine Campaign Procedure and modify Idle Control System as outlined in this Bulletin.


Campaign Summary: Several items influence the idle system and must be checked/adjusted before the idle system can be adjusted. It is, therefore, very important to follow the sequence of the procedure described below. Details of these items are included in the next section of this Bulletin.


1. Check/Replace Ignition Components.


2. Check for/install 35~C Thermotime Switch.


3. Install Purge Control Module.


4. Check for/Install 560 OHM - 270 OHM Resistor. <


5.Adjust Valve Clearance.


6. Perform Engine Test with BMW Service Tester. Value to Microfiche and Adjust, if necessary.


7. Clean the Injectors/Check A/C Freon Charge.


8. Replace Idle Control Unit.


9. Adjust Idle Control Valve Current, Engine CO and RPM.


10. Perform Quality Control of Installed Systems and Road Test for Driveability Problems.


11. If Driveability Unsatisfactory, Clean Carbon from Intake Valves.


Campaign Details:


1. CHECK/REPLACE IGNITION COMPONENTS. Check spark plugs gap. If required replace ignition components. A new camshaft rotor adapter now allows upgrading early vehicles (prior to 1/84) to the Current 30KV components. Specific details of this procedure are covered S.I. 12 03 86 (1206).


2. CHECK FOR/INSTALL 35~C THERMOTIME SWITCH. (1982 Model Year - ONLY) Inspect existing thermotime switch, if a 17 0C thermotime switch is found, replace it with a 35~C switch. Specific details of this procedure are covered in S.I. 13 03 83 (727).


3. INSTALL PURGE CONTROL MODULE. A new Purge Control System has been designed that meters evaporative purge vapors only when sufficient throttle airflow is present to prevent hesitation. A new Purge Control Module and harness should be installed in accordance with the detailed instructions in S.I. 13 06 86 (1161).
4. CHECK FOR/INSTALL 560 OHM - 270 OHM RESISTOR. Vehicles produced between 9/81 and 2/83 should have a 560 OHM resistor installed in the NTC line and vehicles produced after 2/83 should have a 270 OHM resistor installed. Check and assure that the proper resistor is installed in accordance with S.I. 11 11 84 (920).
5. ADJUST VALVE CLEARANCE. Adjust valve clearance to 0.30 mm with cold engine (maximum coolant temperature 95~F/35~C) or to 0.35 mm with engine full warm.

6. PERFORM ENGINE TEST WITH BMW SERVICE TESTER.


Hook up car to BMW Service Tester and assure that correct Nominal Values microfiche is inserted.


Perform engine test. Compare nominal value to microfiche and adjust if necessary. At Engine Test Step 10, Check Fuel Pressure only. DO NOT perform CO adjustment at this time.*


7. CLEAN FUEL INJECTORS. Refer to S.I. 13 08 86 (1176) ford detailed procedure. CHECK A/C FREON CHARGE as per S.I. 13 04 85 (1036). Connect the Fuel Injector Cleaner as described in the above bulletin. Once you get to Step 10 of this S.I., do not run the engine at 3000 RPM as described. First run the engine at 2000 RPM and check the Freon of the A/C system as described in S.I. 13 04 85 (1036). Bleed if necessary. After you finish bleeding the A/C system continue the injector cleaning procedure as per Step 10 of S.I. 13 08 86 (1176): Increase the engine speed to 3000 RPM and keep it there until engine starts to stumble steadily indicating it has used all the cleaning fluid.

8. REPLACE IDLE CONTROL UNIT. Perform Recall 86-EA01. Inspect existing idle control unit located in the glove box and determine if the unit has:


a. A green tape stripe; or


b. Production date code 46 85 or later (Date Code may be 85 46). If existing unit does not meet one of these conditions, it must be exchanged for a correct unit.


NOTE: Units with green tape are OK regardless of the date on the label. Refer to S.I. 13 04 86 (1159) for additional details.



9. ADJUST IDLE CONTROL VALVE CURRENT, ENGINE CO AND RPM. Disconnect plug on idle control valve. Check both pin sockets in the female plug of the idle control valve for tightness. Check sockets individually on male end of idle control valve by turning female plug 90~. Connect the Fluke digital multimeter (BMW Special Tool P/N 88 88 6 900 308) in series with the idle control valve. DO NOT USE AMMETER OF SERVICE TESTER. The BMW Service Tester should be connected to the engine for idle speed and for CO readings.

Disconnect plug connector from throttle butterfly switch. Jump wires #2 and #18 in plug connector (brown and brown/blue). This insures a "closed throttle" signal to the idle control unit.
Start the engine and ensure it is at operating temperature (oil temp. minimum 140~F/60~C)

Measure engine rpm and idle control valve current. The specifications are 470 to 500 mA at 700 + 50 RPM.


If any of these two measurements is out of specifications.

Disconnect the throttle and the kickdown cables.
Clean the throttle housing.

Loosen the locknut of the throttle lever slightly and tap lever to move the throttle plate while watching both RPM and mA, as either might change. Bring RPM and mA into above mentioned specification.

Tighten the locknut.
Adjust throttle switch.
Reinstall and set throttle + kickdown cables.

Check and if necessary adjust CO.If you are unable to obtain correct RPM and mA readings by adjusting the throttle plate, the cause might be:


a) A faulty Idle Control Unit: replace it


b) An air leak. Check inlet manifold and pipes. Disconnect crankcase ventilation hose at the valve cover and plug the hose to check for air leak from crankcase.

Note:


The secondary ventilation hose that tees into the main crankcase ventilation hose and into the inlet manifold provides a metered air bypass around the throttle plate at idle. It should remain connected. Ensure however it is not cracked, thus allowing unmetered outside air into the inlet manifold.

3) Stop the engine and adjust the throttle butterfly switch following the procedure in the Repair Manual Operation no. 13 63 544 page 13-632.
4) Reinstall the throttle cable and kickdown cable and adjust if necessary.
Remove the "jumper" from the throttle butterfly switch plug and reconnect the plug to the switch.
Start engine and accelerate several times from idle to about 1500 RPM, to verify that the desired value of 470 - 500 milliamps is obtained each time the engine returns to idle.
After adjusting CO, recheck RPM and idle valve current. Stop engine, disconnect multimeter, and reconnect plug to idle control valve.
Check and, if necessary, adjust: CO 0.2 - 1.2% HC less than 300 PPM
10. PERFORM QUALITY CONTROL OF INSTALLED SYSTEMS AND ROADTEST FOR DRIVEABILITY. If after performing all operations above as part of the Engine Campaign the driveability of the car is still not satisfactory, only then perform Step 11.

FROM INLET VALVES. Then readjust milliamps and CO. See S.I. 11 10 85 (1011).Warranty Status:


1) Reimbursement for the complete repair outlined in this bulletin will be provided through normal Warranty claim processing with no limitation on age or mileage of the affected vehicle, only when this repair is performed in conjunction with and within the limits described in the BMW "86 ENGINE CAMPAIGN", and the repair is performed on or before May 31, 1987.



The "complete repair" must use the special defect code and labor operation number as detailed on the enclosed summary.

2) Any repairs or adjustments which are found to be necessary while performing the repairs outlined, but which are not included in this bulletin, will be covered under the terms of the applicable BMW Warranty only.
3) If a component installed as part of the "complete repair" requires subsequent (later) replacement, the required repair will be reimburseable ONLY under the normal BMW Limited Warranty for that particular item, using an applicable defect code (NOT the "special defect code") and labor operation from the Flat Rate Manual.
1982 633csi
TimU
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Re: Mystery Silver Relay (what does it do?)

Post by TimU »

Brilliant, thanks for sharing it!
04/1986 635csi Euro spec
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Ralph in Socal
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Re: Mystery Silver Relay (what does it do?)

Post by Ralph in Socal »

I'm hoping the information on this thread can be placed in the Tech Articles for future reference. Great info

Ralph
There is a very fine line between "Hobby" and Mental Illness.

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Re: Mystery Silver Relay (what does it do?)

Post by GRNSHRK »

Uh, you talkin' to me :-k

Yes, I can do that and will get to that shortly :-"

Man, that's quite a list #-o
:mrgreen:
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Ralph in Socal
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Re: Mystery Silver Relay (what does it do?)

Post by Ralph in Socal »

GRNSHRK wrote: Fri May 06, 2022 7:57 pm Uh, you talkin' to me :-k

Yes, I can do that and will get to that shortly :-"

Man, that's quite a list #-o
Yes you sir 8)

Makes too much sense to make sure this info is available for future reference. Thank you Bobbo

Ralph
There is a very fine line between "Hobby" and Mental Illness.

85 635csi Zinno Auto
84 528i Euro
83 635 Euro Arktik
81 528i Kastanien 5-speed
88 528e Bronzit (Granpa Car)
86 535i Auto (For Sale)
81 633 csi (retired)
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Re: Mystery Silver Relay (what does it do?)

Post by TimU »

Ralph in Socal wrote: Fri May 06, 2022 6:26 pm I'm hoping the information on this thread can be placed in the Tech Articles for future reference. Great info

Ralph
Please don't.
The Tech Articles section is not available publicly.
It's only visible to registered forum users who now need to pay for site access.

By moving it to the Tech Articles section, the post will disappear from all public search results as well.
04/1986 635csi Euro spec
Australian Delivered, RHD
rhanley 635csi89
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Re: Mystery Silver Relay (what does it do?)

Post by rhanley 635csi89 »

Is there a reason the article can't be left in this section and also be placed in the Tech section? Copy and Paste??
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Re: Mystery Silver Relay (what does it do?)

Post by TimU »

rhanley 635csi89 wrote: Sun May 08, 2022 12:29 pm Is there a reason the article can't be left in this section and also be placed in the Tech section? Copy and Paste??
Yep, that would work
IMHO, It would be better to open up the Tech Articles section to the public though.
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Re: Mystery Silver Relay (what does it do?)

Post by GRNSHRK »

Not to worry, I'll leave this post here and just copy the technical bulletin info into another thread in the "Tech Articles" forum :-"

Tim, I did talk to admin about your issue, sorry to say that he's just gonna leave things as is :-?
:mrgreen:
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Re: Mystery Silver Relay (what does it do?)

Post by TimU »

GRNSHRK wrote: Sun May 08, 2022 5:24 pm Not to worry, I'll leave this post here and just copy the technical bulletin info into another thread in the "Tech Articles" forum :-"

Tim, I did talk to admin about your issue, sorry to say that he's just gonna leave things as is :-?
Thanks Bobbo. Disappointing, but his board/his call. :-#
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Australian Delivered, RHD
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Re: Mystery Silver Relay (what does it do?)

Post by Pod »

TimU wrote: Mon May 09, 2022 1:17 amTim, I did talk to admin about your issue, sorry to say that he's just gonna leave things as is :-?
Thanks Bobbo. Disappointing, but his board/his call. :-#
[/quote]

I think that’s the right thing to do. Those of us who support this forum will surely agree with this decision!
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Re: Mystery Silver Relay (what does it do?)

Post by TimU »

This is probably the wrong thread for a debate about board politics, but I'm never a fan of totally hiding information from people.
Give them a snippet, or throw up a paywall, sure, but it's self defeating for information to be totally undiscoverable.

Posts in the Tech Articles section are totally hidden from anyone except paid and registered members. You don't know the articles exist until you pay for forum membership.

Which is why I'm not a fan of MOVING articles to that section - they entirely disappear from public view.
04/1986 635csi Euro spec
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Pod
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Re: Mystery Silver Relay (what does it do?)

Post by Pod »

If Brian didn’t continue to support this forum, there would be nothing at all to view, so I, for one, totally agree that people should make a contribution towards the running costs!
TimU
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Re: Mystery Silver Relay (what does it do?)

Post by TimU »

Yeah I have no issues with that, and readily paid for my new membership late last year.

But I don't think we're talking about the same thing though mate. This is probably not the right thread for the discussion so I'll leave it alone for now.
04/1986 635csi Euro spec
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songzunhuang
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Re: Mystery Silver Relay (what does it do?)

Post by songzunhuang »

Late to this discussion, but can't shake the fact that we still don't know what that rectangular "relay" does!
I took mine out and tried to energize all the combination of legs and never heard the tell-tale "click". I wonder if it's a relay?

Obviously, my car has this part as well. I've removed it and put it in the glove compartment, just in case.
I also was told that all the wiring connected to it was no longer needed. I removed the wiring, but kept it just in case something comes up in the future. This was captured in "My Project" thread.

Here's a picture of the harness that I removed. This was removed on March 28, 2020.
Emissions wiring removed
Emissions wiring removed
Purge wiring.png (1.69 MiB) Viewed 1750 times
I recall having to cut one wire as well. The car has run for years without issue due to this removal.
-----
Song Huang
1984 633CSi
Last 7 of VIN: 6997383
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