Engine - Stalls at Idle/Gear Engagement/Tip In
Article No.93-9-6
04/28/93
STALLS - 2.3 HSC - DURING INITIAL START-UP, AT IDLE AND GEAR ENGAGEMENT, TIP-IN OR DECEL
FORD:
1988-91 TEMPO
LINCOLN-MERCURY:
1988-91 TOPAZ
ISSUE:
Engine "stalls" at idle, gear engagement, tip-in or decel may be caused by one or a combination of the following reasons, Throttle Position (TP) sensor, throttle body deposits, thermostat early to open, fuel pump performance, fuel injector deposits, Idle Air Valve Control (IAVC) and Intake Valve (IVD) deposits.
ACTION:
Diagnose and repair the following causes of engine "stall". Refer to the following procedure for diagnostic and repair details.
DIAGNOSIS AND REPAIR PROCEDURE
1. THROTTLE POSITION SENSOR (TPS) - CONCERN
a. Inspect the TP sensor on the vehicle. If the part number is (E83F-9B989-AA) and does not have a yellow dot, replace the TP sensor with a CTS corporation Throttle Position (TP) sensor. Service part number F1DZ-9B989-A.
2. THROTTLE BODY DEPOSITS
a. Check engine idle RPM. Refer to the Engine/Emissions Diagnostic ("H") Manual. If the engine RPM is not between 900-1100 RPM do the following:
^ 1988 - 1990 Calibrations; Install Idle Air Control Valve Service Kit (F2PZ-9F939-A), refer to the instruction sheet included in the Kit for installation details.
^ 1991 Calibration; These calibrations have a sludge tolerant throttle body design which has a special coating applied to the throttle bore and plate throttle body. Cleaning or use of the Idle Air Control Valve Service Kit is not allowed. Refer to the 1991 Engine/Emission Diagnostic Manual for correct air flow adjust procedure.
3. THERMOSTAT - EARLY TO OPEN
NOTE:
AN EARLY TO OPEN THERMOSTAT STARTS TO OPEN AT A LOWER TEMPERATURE THAN THAT FOR WHICH IT WAS DESIGNED.
This concern applies to vehicles with a fully warmed engine that stall/quit on light accelerations from a complete stop. This concern tends to increase in ambient temperatures of 30-60~ F (-1 to 16~ C). Use the following procedure to evaluate thermostat performance.
a. Set the heater control button to defrost/floor and the temperature control lever to maximum warm. Set the heater fan blower speed to low.
b. Fully warm up the engine until cooling fan cycles.
c. Drive the vehicle at a steady state of speed of 45 MPH (72 Km/h) for at least 2 miles (3 Km). Measure the ECT voltage during the drive after it stabilizes. (Note: Must be measured while driving with the heater controls set per Step 3a).
d. If the stabilized ECT voltage reads above .80 volts during the road test, the thermostat is defective and should be replaced.
4. FUEL INJECTOR DEPOSITS (1988-1990 CALIBRATIONS)
a. Install the Rotunda Fuel lnjector Tester/Cleaner 113-0001 and check the flow on all injectors. If an injector is suspect, clean it until it is in specification or, if necessary, replace it (Refer to TSB 91-11-4). If replacement is required, install Deposit Resistant Injectors (DRI'S). These DRI'S are acceptable service replacements for non-deposit resistant injectors that exhibit lean fuel flow. The fuel injector service part number for 1988/1990 2.3L HSC/HSO Tempo/Topaz (all calibrations) is F13Z-9F593-A (Refer to TSB 92-24-5).
5. IDLE AIR CONTROL VALVE - (IACV)
a. If the procedures above do not correct stalling during initial start-up, at idle and gear engagement or tip-in hesitations, replace the Idle Air Control Valve.
6. INTAKE VALVE DEPOSITS (IVD) - COLD STARTS ONLY (STALLS AT IDLE AND UPON GEAR ENGAGEMENT AFTER COLD START)
a. Inspect for intake valve deposits according to TSB # 92-19-3 using the Rotunda Carbon Cleaning System 014-00975. If carbon deposit levels are determined to be too high, use the IVD cleaning procedure in TSB 92-19-3.
NOTE:
REFER TO OASIS SPECIAL MESSAGES 9000 THROUGH 9023 TO IDENTIFY APPROPRIATE BRANDS OF FUEL TO USE TO MINIMIZE OR ELIMINATE INTAKE SYSTEM DEPOSITS.
PART NUMBER PART NAME CLASS
F1DZ-9B989-A Throttle Position Sensor B
F2PZ-9F939-A Idle Air Control Valve Service B
Kit
F13Z-9F593-A Fuel Injector - 2.3L HSC/HSO B
(1988/1990)
OTHER APPLICABLE ARTICLES:
91-11-4, 92-19-3, 92-24-5
WARRANTY STATUS:
Eligible Under Basic Warranty Coverage, Emissions Warranty Coverage
OPERATION DESCRIPTION TIME
930906A Inspect TPS 0.2 Hr.
930906B Inspect And Replace TPS 0.5 Hr.
930906C Inspect And Replace TPS, 0.9 Hr.
Install Service Kit
930906D Inspect And Replace TPS, 0.9 Hr.
Adjust Air Flow
930906E Test Thermostat 0.3 Hr.
930906F Test And Replace 0.8 Hr.
Thermostat
930906G Test And Clean All Injectors 1.0 Hr.
930906H Test And Clean All Injectors 2.0 Hrs.
/ Replace 1 Injector
930906I Test, Clean And Replace All 2.1 Hrs.
Injectors
930906J Remove And Replace Idle 0.6 Hr.
Air Control Valve
930906K Inspect Intake Valves With 1.0 Hr.
Bore Scope
930906L Inspect Intake Valves With 3.3 Hrs.
Bore Scope And Clean
Valves With Blaster
DEALER CODING
BASIC PART NO. CONDITION CODE
9B989 08
OASIS CODES:
607000, 607400, 607500, 607700