Engine - Rough Idle/Surge/Stalling

85ford14

Article No.
5-14-14

STALLING - ENGAGEMENT/DECEL/IDLE/PARKING MANEUVERS - 2.3L HSC CFI

SURGE - DECEL BUCKING/TRAILER HITCHING - 2.3L HSC CFI

IDLE - ROUGH/ROLLING - 2.3L HSC CFI

FORD
1985 TEMPO

LINCOLN-MERCURY
1985 TOPAZ

If, after performing normal diagnostics, the vehicle still exhibits some or all of the detailed symptoms listed below, perform the following checks and/or procedures:

STALLING
^ On engagement after initial cold Start 1*
^ Following a decel (Hot/Cold)
^ At idle (Hot/Cold)
^ When turning steering wheel against stops, for example: parallel parking maneuver (Hot/Cold).
^ On Hot/Hard restarts.

ROUGH IDLE
^ Engine speed may be unstable for brief periods or continuously.
^ Engine speed may roll up and down from 500 RPM to 1600 RPM slowly and/or intermittently.

SURGING
^ Surges at highway speeds light loads.
^ Decel bucking/trailer hitching. 1* Strategy requires engagement within 20 seconds after start (reference TSB 85-14-13).
Vehicle System Checks:
1. Check that all electrical and vacuum connections of the engine control system are properly attached utilizing visual inspection and wiggle test. (Pay particular attention to ACT, MAP and TFI connections).

2. Check base engine timing and reset to 10 degrees BTDC as required. If pings/knocks are present set to 8 degrees.

NOTE:
If timing is adjusted then an Authorized Modifications sticker should be installed noting changes.

Authorized Modification decal:

Obtain an Authorized Modification 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.
3. Check for proper fuel pump/check valve operation. (See Procedure 1, page 35). Check for injector/regulator integrity. (See Procedure 2 on page 37). Check integrity of fuel pressure regulator, fuel filter and fuel return line. (See Procedure 3 on page 38).

4. Check the throttle stop screw and adjust to 590 RPM (ATX) 640 RPM (MTX) maximum. Check TV Linkage Rod adjustment per TSB 85-9-29. (Revise 550 RPM stated in TSB to 590 RPM).

5. After performing Steps 1 through 4, retest the vehicle. If customer concern(s) is still present, replace the fuel injector. (See Procedure 4 on page 38). If new injector corrects concern(s), return vehicle to customer; otherwise, reinstall original injector.

6. Review the articles listed in the following "TSB Application Chart" to assure that other causes for the symptom(s) were not overlooked.
NOTE:
Processor replacement or battery terminal disconnect requires adaptive learning procedure per TSB 85-9-17.

TSB APPLICATION CHART

SYMPTOM TSB NO.
Fuel Injector/Fuel Pressure Regulator 85-9-12
Leaking

Hard/No Start 85-9-13

Idle Speed - Adaptive Learning 85-9-17
Strategy

Loading/Stalling - ACT Harness 85-9-20
- Intermittent Open Circuit

No Start, Idle Rough, Spark Knock 85-9-22

Stalls - Engagement/Decel after 85-9-26
Initial Cold Start 85-9-27

Surge/Stall, Poor Idle, Loss of Power, 85-9-28
AM Radio Noise, Alternator Regulator

OTHER APPLICABLE ARTICLES: NONE
WARRANTY STATUS: Reimbursable within the provisions of the Warranty and Policy Manual.
OPERATION: SP9593B85 - Check and reset base timing.
TIME: 0.4 Hr.
OPERATION: SP9593B185 - Check fuel pump/check valve operation.
TIME: 0.3 Hr.
OPERATION: SP9593B285 - Check injector/regulator integrity.
TIME: 0.2 Hr.
OPERATION: SP9593B385 - Check fuel pressure regulator, fuel filter and fuel return line.
TIME: 0.4 Hr.
OPERATION: SP9593B485 - Road test vehicle
TIME: 0.3 Hr.
OPERATION: SP9593B585 - Replace injector.
TIME: 0.2 Hr.
OPERATION: SP9593B685 - Repeat test of injector/ regulator - integrity.
TIME: 0.2 Hr.
OPERATION: SP9593B785 - Reinstall original injector
TIME: 0.2 Hr. DLR. CODING: Basic Part No. 9593 - Code: 09

Figure 17 - Check for Proper Fuel Pump/Check Valve Operation:

Procedure 1

CHECK FOR PROPER FUEL PUMP/CHECK VALVE OPERATION
Idle Stall/Hesitation and fuel pressure leak down following ignition switch "turn off" can result from poor fuel pump/check valve performance. The pump/check valve operation can be checked using the following procedure and test apparatus shown in Figure 17 or equivalent.
1. Disconnect electrical connection to inertia switch.

2. Crank engine for 5 seconds to reduce system fuel pressure.

NOTE:
Must use a 30 psi gauge to get an accurate reading. If a 150 psi gauge is used, low end readings may vary 3-5 psi lower than actual.
TEST APPARATUS (or equivalent)

PART NUMBER DESCRIPTION QTY.

E53Z-9J291-A Fuel Line Assy. 1
Weatherhead Street Tee 1/4 M & F 1
3750X4 or equiv. Pipe Thread
(procure locally)
McDaniel Ctrl's. Pressure Gauge 1
Model UB 1/4" 0-30 psi
Bottom Connect (procure locally)
HOKE 3812F4B Needle Valve 1/4 NPT 1
or equiv. (procure locally)
E53Z-9F681-A Fitting 2
N802239-S Hairpin Clip 1
3. Remove hairpin clip from push connect fitting at the fuel charging assembly and disconnect fuel line from fuel charging assembly using appropriate safety precautions (for example, a cloth over end of fuel line.)

4. Using hairpin clips, install test apparatus, between the disconnected fuel line and the fuel charging assembly. The shut-off valve should be in the open position.

5. Reconnect the inertia switch.

6. Start the engine and allow fuel pressure to stabilize. If engine will not start and fuel pressure is 69 kPa. (10 psi) or less, check fuel pump electrical circuit for continuity and fuel pump for flow per TSB 85-9-13. Replace fuel pump/sender unit assembly if faulty and retest to confirm proper operation. If fuel pressure is between 69 and 90 kPa (10-13 psi), increase pressure to 100 kPa (14.5 psi). Remove welsh plug on top of fuel pressure regulator to gain access to fuel adjustment screw.

7. If fuel pressure is within 90-110 kPa. (13-16 psi.) the operating pressure is normal. When engine operation is stable, close the shut-off valve. If pump operation is normal, fuel dead head pressure should increase to 124-172 kPa. (18-25 psi).

8. When the fuel starved engine stalls, check the pressure gauge indication. If pressure is maintained above 69 kPa. (10 psi) for 60 seconds, the check valve in the fuel pump sending unit is functioning correctly.

NOTE:
After engine stalls, fuel pressure may decrease.
9. Open the shut-off valve slowly. If the fuel pressure bleeds down to zero, check for pressure regulator or fuel injector leakage. (See Procedures 2 and 3).

10. If the system remains slightly pressurized, the fuel system is "O.K.".

11. Repeat Steps 1 and 2 above. Remove hairpin clips from the test apparatus push connect fittings, remove test apparatus, replace vehicle fuel line using a new hairpin clip. Reconnect the inertia switch.

PROCEDURE 2

FUEL CHARGING ASSEMBLY INJECTOR/REGULATOR - VACUUM BLEED DOWN SYSTEM CHECK

2.3L HSC CFI-IV - 1985 TEMPO, TOPAZ

TEST STEP RESULTS
ACTION TO TAKE
STEP 1

Remove fuel inlet and outlet lines at fuel charging ^ Vacuum holds less or ^ Injector/"O"-Ring
assembly (FCA). Connect hand vacuum pump at drops less than 1 in. Hg regulator seat/valve
charging assembly inlet (outlet open) and apply in 30 seconds. system O.K. STOP
15-20 in. Hg vacuum. Vacuum should drop no
greater than 1 in.-Hg in 30 seconds. ^ Vacuum drops greater ^Go to Step 2.
than 1 in.-Hg in 30 seconds.

STEP 2

Cap outlet at fuel charging assembly (FCA) and ^ Vacuum holds or drops ^ Remove regulator
repeat Step 1. less than 1 in.-Hg in 30 diaphragm, seat/valve
seconds. and clean or replace as
necessary and repeat

^ Vacuum drops greater ^ Go to Step #3 than 1 in.-Hg in 30 seconds.

STEP 3

Plug injector tip outlet with index finger and repeat ^ Vacuum holds or drops ^ Injector stuck open -
Step 1. less than 1 in.-Hg in 30 replace and retest.
30 seconds.

^ Vacuum drops greater ^ Injector "O"-ring leak than 1 in.-Hg. (upper or lower) replace
O-ring and retest.
Procedure 3

FUEL CHARGING ASSEMBLY (F.C.A.) FUEL PRESSURE REGULATOR, UNDERHOOD FUEL FILTER AND RETURN LINE SYSTEM CHECK 2.3L HSC CFI-IV - 1985 TEMPO, TOPAZ

TEST STEP RESULTS ACTION TO TAKE
STEP 1

Check system fuel pressure using 0-30 psi test ^ Pressure low ^ Perform fuel pump
described in Procedure at idle. System pressure less than 13 psi check procedure per
should be between 13-12 psi. Procedure 1.

^ If pressure is still low, perform FCA injector/ regulator vacuum bleed down system check.

^ Pressure high ^ Connect external fuel greater than 16 psi line from FCA. Outlet to
vehicle tank and retest
- If O.K. check for blocked or kinked return line.

^ If pressure is still high, check FCA for blockage.

^ Pressure normal ^ Check fuel pump flow
13-16 psi drive concern per fuel pump check
still present procedure Procedure 1
Procedure 4 INJECTOR REPLACEMENT
Disassembly
1. Remove fuel injector retaining screw and retainer.

2. Remove injector assembly and lower O-ring.

Assembly
NOTE: This procedure is different from that shown in Shop Manual E, page 24-03-4.
1. Lubricate new lower O-ring and injector seat area with clean engine oil. (Do not use transmission oil.)

2. Install lower O-ring on injector.
3. Lubricate upper O-ring, clean and lubricate throttle body O-ring seat.

4. Install injector by centering and applying a steady downward pressure with a slight rotational force.

5. Install injector retainer and retaining screw.

6. Tighten retainer screw to 2-2.5 N-m (18-22 in.lb.)

7. Perform Fuel/Charging Assembly lnjector/Regulator - Vacuum Bleed Down System check per Procedure 2.