TSB: D002/96

ROUGH IDLE AND/OR ENGINE STALL AFTER COLD START

AFFECTED MODELS

1994-96 323/Protege with the following engines: B6 and BP

1994-96 MX-3 with B6 engine.

1990-96 MX-5 with B6 and BP engines.

1994-96 626/MX-6 with a 4 cyl. engine and a VIN 1YVGE**C*T5580486 and lower.

DESCRIPTION

Rough idle and/or engine stall may occur after cold start and continue until the engine reaches normal operating temperature. This condition may occur in cold ambient temperatures 14 degrees to 50 degrees (F) (-10 degrees to 10 degrees C).

The following causes may result in poor driveability in cold ambient temperatures:

  1. Vehicles with long oil pump control plungers as a countermeasure for HLA noise. The concern may be caused when the oil pump control plunger becomes struck. When this occurs, the oil pressure becomes excessive. The high pressure is applied directly to the HLA, which pushes the valve down and prevents complete closing.

    • To prevent this concern, the plunger has been modified.

  2. B6 DOHC Engines Only. Compression loss due to poor seating of the exhaust valve caused by thermal expansion.

    • To prevent this occurrence, an exhaust valve stem with low thermal expansion coefficient is used.

    • A stronger valve spring is used so that the HLA will absorb the valve's expansion during cold ambient temperatures.

DIAGNOSTIC PROCEDURE

Follow this procedure if the vehicle has a B6 DOHC engine. If the vehicle is not equipped with a B6 DOHC engine, perform REPAIR 1.

1. Prepare to measure the engine oil pressure.
2. Start the engine.
3. Measure the oil pressure immediately after starting (during fast idle).

NOTE: If the diagnostic inspection is inconclusive, proceed to step 4.

4. Allow the engine to run for 2 or 3 minutes.
5. Raise engine RPM to 3,000.
6. Measure the oil pressure.

REPAIR 1

Replace the oil pump with a new one.

NOTE:

PARTS INFORMATION for REPAIR 1



Part Number

Description

Qty.

Inter.

Models

New

Old

B6S8-14-100H

B6S8-14-100G

Oil Pump

1


323, Protege, MX-3, MX-5 with BP and B6 Engines

FS01-14-115

JF01-14-115

Control Plunger

1


FS01-14-100L

FS01-14-100K

Oil Pump

1


626/MX-6 with 4 Cylinder Engines

FS01-14-115

JF01-14-115

Control Plunger

1


The new part can be used in place of the old part but the old part can not be used in place of the new part.
The new part can be used in place of the old part but the old part can not be used in place of the new part.
The new part can be used in place of the old part but the old part can not be used in place of the new part.
The new part can be used in place of the old part but the old part can not be used in place of the new part. 

WARRANTY INFORMATION for REPAIR 1

(Applies To Verified Customer Complaints On Vehicles Covered Under Normal Warranty. Refer To The SRT Microfiche For Warranty Term Information.)

Warranty Type
A
Symptom Code
03
Damage Code
92
Part Number Main Cause
B6S8-14-100
Quantity
1
Operation Number
D010*R* (The asterisk "*" can be any letter, refer to the SRT)
Labor Hours
Refer to the SRT

REPAIR 2

Replace exhaust valve and springs with modified parts.

NOTE: DO NOT replace HLA's to correct this concern.

PARTS INFORMATION for REPAIR 2



Part Number

Description

Qty.

Inter.

New

Old

B660-12-121A

B660-12-121

Exhaust Valve

8


B660-12-125A

B61P-12-125

Valve Spring

8


The new part can be used in place of the old part but the old part can not be used in place of the new part.
The new part can be used in place of the old part but the old part can not be used in place of the new part.

NOTE: Part No. B695-12-121B (exhaust valve) may also be used for this repair.

WARRANTY INFORMATION for REPAIR 2

(Applies To Verified Customer Complaints On Vehicles Covered Under Normal Warranty. Refer To The SRT Microfiche For Warranty Term Information.)

Warranty Type
A
Symptom Code
03
Damage Code
97
Part Number Main Cause
B660-12-121A or B660-12-125A
Quantity
8
Operation Number/Labor Hrs.
XX860XR4/7.1 Hrs (MX-3) XX860X86/6.6 Hrs. (MX-5)

Copyright © Mazda North American Operations