Campaign - Rough Idle, Low Idle, Idle Speed Fluctuates
86BMW09GROUP 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.
- Perform Engine Test
- Compare Nominal 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 (Illustration A).
- 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 (Illustration B). 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.
11. IF REQUIRED REMOVE CARBON 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.