Intermittent MIL ON/Rich Condition

88ford09

Article No. 88-10-5

LIGHT - MALFUNCTION INDICATOR (MIL) - INTERMITTENT OPERATION - 2.3L OHC TURBO WITH AUTOMATIC TRANSMISSION - VEHICLES BUILT AFTER 11/01/86

FORD: 1987-88 THUNDERBIRD

CALIBRATION: 7-06E-R11


ISSUE: A "Check Engine" Malfunction indicator Light (MIL) that turns "on" and "off" may be caused by an intermittent "rich fuel" condition. The "rich fuel" condition may be caused by one or more fuel injectors that are operating out of specification or the EEC IV processor.

ACTION: To correct this, perform the following diagnostic service procedure to determine if one or more of the fuel injecters and EEC IV processor require replacement. Service code "42" will be displayed during the EEC IV Quick Test indicating a faulty EGO (Exhaust Gas Oxygen) sensor. Service code "42" will also be stored in continuous Self-Test memory.

1. Perform an EEC IV Quick Test, service as required.

NOTE: IF ROUTINE DIAGNOSTICS (PINPOINT TESTS) DO NOT CORRECT THE FAULT, PROCEED TO STEP 2.

2. Install a new level EEC IV processor, (E8SZ-12A650-AGA).

3. Check to see if the condition still exists by doing the following:

a. Warm engine to operating temperature by driving the vehicle for several miles.

NOTE: IF THE ENGINE IS WARMED UP IN NEUTRAL, THE "MIL CHECK ENGINE LIGHT" MAY COME ON BECAUSE THE EEC IV PROCESSOR HAS NOT ADAPTED TO THE FUEL CHARGING HARDWARE.

b. Position the gear selector in drive "D". Idle the engine one (1) minute with the air conditioning "on" and the blower fan at maximum speed.

c. Shift the transmission into neutral or park. Idle engine for one (1) minute in neutral or park with the air conditioning "on" and the blower fan still set at maximum speed.

d. Shift the transmission into drive and repeat Steps 3b and 3c with all accessories turned "off".

NOTE: THE MALFUNCTION INDICATOR LIGHT "CHECK ENGINE" SHOULD STAY "OFF" DURING ALL IDLE ROUTINES. SERVICE "42" SHOULD NOT APPEAR IN CONTINUOUS MEMORY DURING EEC IV QUICK TEST. IF THE CONDITION IS STILL PRESENT, PROCEED TO STEP 4.

4. Flow test the fuel injectors using the Rotunda Injector/Cleaner, 113-00001. Locate the "BROWN BAND" on the flowmeter. Replace fuel injectors that test above the midpoint of the "BROWN BAND" on the flowmeter.

NOTE: THE YELLOW WARRANTY CODE TAG MUST BE MARKED "MIL" IN THE "REASON REPLACEMENT PART REQUIRED" LINE.




Obtain an Authorized Modifications Decal and list the date, dealer number, and summary of alterations performed. Select a prominent place adjacent to the Vehicle Emission control Information Decal suitable for installing the Authorized Modifications Decal. Clean the area, install the decal, and cover it with a clear plastic decal shield.

PART NUMBER PART NAME CLASS

E7SZ-9F593-A Fuel Injecter B
E8SZ-12A650-AGA EEC IV Processor B

OTHER APPLICABLE ARTICLES: None
WARRANTY STATUS: Eligible Under Basic Warranty Coverage/ Eligible Under Emissions Coverage if EEC IV processor is defective
OPERATION: 881005A - Install EEC IV processor only
TIME: 1.5 Hrs.

OPERATION: 881005B - Flow test injectors, install injectors and EEC IV processor
TIME: 3.1 Hrs.
DLR. CODING: Basic Part No. MIL
Condition Code: 09