1998 OPEL FRONTERA fuel pressure

6E–265 ENGINE DRIVEABILITY AND EMISSIONS
Surges and/or Chuggles Symptom
StepActionVa l u e ( s )Ye sNo
1DEFINITION:
Engine power variation under steady throttle or cruise.
Feels like the vehicle speeds up and slows down with
no change in the accelerator pedal.
Was the “On-Board Diagnostic (OBD) System Check”
performed?
—Go to Step 2
Go to OBD
System
Check
21. Perform a bulletin search.
2. If a bulletin that addresses the symptom is found,
correct the condition as instructed in the bulletin.
Was a bulletin found that addresses the symptom?
—Verify repairGo to Step 3
3Was a visual/physical check performed?
—Go to Step 4
Go to
Visual/Physic
al Check
4Be sure that the driver understands transmission
torque converter clutch and A/C compressor operation
as explained in the owner’s manual.
Inform the customer how the TCC and the A/C clutch
operate.
Is the customer experiencing a normal condition?
—System OKGo to Step 5
51. Check the the fuel control heated oxygen sensors
(HO2S, B1S1 and B2S1). The fuel control heated
oxygen sensors (HO2S) should respond quickly to
different throttle positions. If they don’t, check them
for silicon or other contaminants from fuel or use of
improper RTV sealant. The sensors may have a
white powdery coating.
Silicon contamination causes a high but false
HO2S signal voltage (rich exhaust indication).
The PCM will then reduce the amount of fuel
delivered to the engine, causing a severe
driveability problem. For more information, refer
to
Powertrain Control Module (PCM) and Sensors.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 6
61. Check the fuel pressure. Refer to Fuel System
Pressure Test
.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 7
7Monitor the long term fuel trim on Tech 2.
Is the long term fuel trim significantly in the negative
range (rich condition)?
—Go to Step 8Go to Step 9
81. Check items that can cause the engine to run rich.
Refer to
Diagnostic Aids in DTC P0172 Diagnostic
Support
.
2. If a problem is found, repair as necessary.
Was a problem found?
—Go to Step 10Verify repair
91. Check items that can cause the engine to run lean.
Refer to
Diagnostic Aids in DTC P0171.
2. If a problem is found, repair as necessary.
Was a problem found?
—Go to Step 10Verify repair

6E–268
ENGINE DRIVEABILITY AND EMISSIONS
Lack of Power, Sluggish or Spongy Symptom
StepActionVa l u e ( s )Ye sNo
1DEFINITION:
Engine delivers less than expected power. Little or no
increase in speed when accelerator pedal is pushed
down part-way.
Was the “On-Board Diagnostic (OBD) System Check”
performed?
—Go to Step 2
Go to OBD
System
Check
21. Perform a bulletin search.
2. If a bulletin that addresses the symptom is found,
correct the condition as instructed in the bulletin.
Was a bulletin found that addresses the symptom?
—Verify repairGo to Step 3
3Was a visual/physical check performed?
—Go to Step 4
Go to
Visual/Physic
al Check
41. Remove and check the air filter element for dirt or
restrictions. Refer to
Air Intake System in
ON-Vehicle Service.
2. Replace the air filter element if necessary.
Was a repair required?
—Verify repairGo to Step 5
51. Check for low fuel pressure. Refer to Fuel System
Pressure Test
.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 6
61. Check for water- or alcohol-contaminated fuel.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 7
71. Using Tech 2, monitor the knock sensor (KS)
system for excessive spark retard activity. Refer to
Knock Sensor (KS) System.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 8
81. Check for proper ignition voltage output with spark
tester J 26792 (ST-125). Refer to
Electronic Ignition
System
for procedure.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 9
91. Remove the spark plugs and check for wet plugs,
cracks, wear, improper gap, burned electrodes, or
heavy deposits. Refer to
Electronic Ignition
System
.
NOTE: If spark plugs are gas or oil fouled, the cause of
the fouling must be determined before replacing the
spark plugs.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 10
101. Check the ignition coils for cracks or carbon
tracking.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 11

6E–270
ENGINE DRIVEABILITY AND EMISSIONS
Detonation/Spark Knock Symptom
StepActionVa l u e ( s )Ye sNo
1DEFINITION:
A mild to severe ping, usually worse under acceleration.
The engine makes sharp metallic knocks that change
with throttle opening.
Was the “On-Board Diagnostic (OBD) System Check”
performed?
—Go to Step 2
Go to OBD
System
Check
21. Perform a bulletin search.
2. If a bulletin that addresses the symptom is found,
correct the condition as instructed in the bulletin.
Was a bulletin found that addresses the symptom?
—Verify repairGo to Step 3
3Was a visual/physical check performed?
—Go to Step 4
Go to
Visual/Physic
al Check
4If Tech 2 readings are normal (refer to Ty p i c a l S c a n
Va lu es
) and there are no engine mechanical faults, fill
the fuel tank with a known quality gasoline that has a
minimum octane rating of 87 and re-evaluate the
vehicle performance.
Is detonation present?
—Go to Step 5Verify repair
51. Check the transmission range switch circuit. Use
Tech 2 and be sure Tech 2 indicates that the vehicle
is in drive with the gear selector in drive or overdrive.
2. If a problem is found, diagnose and repair the
transmission range switch as necessary (refer to
4L30-E Automatic Transmission Diagnosis).
Was a problem found?
—Verify repairGo to Step 6
61. Check TCC operation. Refer to 4L30-E
Transmission Diagnosis
.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 7
71. Check for obvious overheating problems:
Low engine coolant.
Restricted air flow to radiator, or restricted
water flow through radiator.
Correct coolant solution should be a 50/50 mix
of approved antifreeze/coolant and water.
Refer to
Engine Cooling.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 8
81. Check fuel pressure. Refer to Chart Fuel System
Pressure Test.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 9
91. Check items that can cause an engine to run lean
(long term fuel trim significantly in the positive
range). For a lean condition, refer to
Diagnostic
Aids
in DTC P0171 Diagnostic Support.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 10

6E–273 ENGINE DRIVEABILITY AND EMISSIONS
Rough, Unstable, or Incorrect Idle, Stalling Symptom
StepNo Ye s Va l u e ( s ) Action
101. Visually/physically inspect for the following
conditions:
Restricted air intake system. Check for a
possible collapsed air intake duct, restricted
air filter element, or foreign objects blocking
the air intake system.
Throttle body. Check for objects blocking the
IAC passage or throttle bore, excessive
deposits in the IAC passage and on the IAC
pintle, and excessive deposits in the throttle
bore and on the throttle plate.
Large vacuum leak. Check for a condition that
causes a large vacuum leak, such as an
incorrectly installed or faulty crankcase
ventilation valve or a disconnected brake
booster hose.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 8
11Check the injector connections. If any of the injectors
are connected to an incorrect cylinder, correct as
necessary.
Was a problem found?
—Verify repairGo to Step 12
121. Perform the “Injector Coil/Balance Test” in Fuel
Metering System
.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 13
131. Check for fuel in the pressure regulator vacuum
hose.
2. If fuel is present, replace the fuel pressure regulator
assembly. Refer to
Fuel Metering System.
3. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 14
141. Check for proper ignition voltage output with spark
tester J 26792 (ST-125). Refer to
Electronic Ignition
System
for the procedure.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 15
151. Remove spark plugs. Check for wet plugs, cracks,
wear, improper gap, burned electrodes, or heavy
deposits. Refer to
Electronic Ignition System.
NOTE: If spark plugs are gas or oil fouled, the cause of
the fouling must be determined before replacing the
spark plugs.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 16
161. Check for a loose ignition coil ground.
Refer to
Electrical Ignition System.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 17

6E–275 ENGINE DRIVEABILITY AND EMISSIONS
Poor Fuel Economy Symptom
StepActionVa l u e ( s )Ye sNo
1DEFINITION:
Fuel economy, as measured by an actual road test, is
noticeably lower than expected. Also, economy is
noticeably lower than it was on this vehicle at one time,
as previously shown by an actual road test.
(Non-standard tires will cause odometer readings to be
incorrect, and that may cause fuel economy to appear
poor when it is actually normal.)
Was the “On-Board Diagnostic (OBD) System Check”
performed?
—Go to Step 2
Go to OBD
System
Check
21. Perform a bulletin search.
2. If a bulletin that addresses the symptom is found,
correct the condition as instructed in the bulletin.
Was a bulletin found that addresses the symptom?
—Verify repairGo to Step 3
3Was a visual/physical check performed?
—Go to Step 4
Go to
Visual/Physic
al Check
4Check owner’s driving habits.
Is the A/C “ON” full time (defroster mode “ON”)?
Are tires at the correct pressure?
Are excessively heavy loads being carried?
Is acceleration too much, too often?
Was a problem found?
—Go to Step 5Go to Step 6
5Review the items in Step 4 with the customer and
advise as necessary.
Is the action complete?
—System OK—
61. Visually/physically check: Vacuum hoses for splits,
kinks, and improper connections and routing as
shown on the “Vehicle Emission Control
Information” label.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 7
71. Remove and check the air filter element for dirt or for
restrictions. Refer to
Air Intake System.
2. Replace the air filter element if necessary.
Was a repair required?
—Verify repairGo to Step 8
81. Remove spark plugs and check for wet plugs,
cracks, wear, improper gap, burned electrodes, or
heavy deposits. Refer to
Spark Plug Replacement.
NOTE: If spark plugs are gas or oil fouled, the cause of
the fouling must be determined before replacing the
spark plugs.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 9
91. Check for low engine coolant level. Refer to Engine
Cooling
.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 10

6E–276
ENGINE DRIVEABILITY AND EMISSIONS
Poor Fuel Economy Symptom
StepNo Ye s Va l u e ( s ) Action
101. Check for an incorrect or faulty engine thermostat.
Refer to
Engine Cooling.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 11
111. Check for low engine compression. Refer to Engine
Mechanical
.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 12
121. Check the TCC operation. Refer to 4L30-E
Transmission Diagnosis
.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 13
131. Check the exhaust system for possible restriction:
Inspect the exhaust system for damaged or
collapsed pipes.
Inspect the muffler for heat distress or possible
internal failure.
Check for a possible plugged three-way
catalytic converter by checking the exhaust
system back pressure. Refer to
Restricted
Exhaust System Check
.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 14
14Check for proper calibration of the speedometer.
Does the speed indicated on the speedometer closely
match the vehicle speed displayed on Tech 2?
—Go to Step 16Go to Step 15
15Diagnose and repair an inaccurate speedometer
condition as necessary. Refer to
Vehicle Speed
Sensor
in Electrical Diagnosis.
Was a problem found?
—Verify repair—
161. Check the air intake system and the crankcase for
air leaks. Refer to
Air Intake System and
Crankcase Ventilation System.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 17
171. Review all diagnostic procedures within this table.
2. When all procedures have been completed and no
malfunctions have been found, review/inspect the
following:
Visual/physical inspection
Te c h 2 d a t a
Freeze Frame data/Failure Records buffer
All connections within a suspected circuit
and/or system.
3. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 18
18Perform the procedure in Fuel System Pressure Test.
Was the fuel pressure normal?
—
Contact
Te c h n i c a l
Assistance
Verify repair

6E–277 ENGINE DRIVEABILITY AND EMISSIONS
Excessive Exhaust Emissions or Odors Symptom
StepActionVa l u e ( s )Ye sNo
1DEFINITION:
Vehicle fails an emission test. Vehicle has excessive
“rotten egg” smell. (Excessive odors do not necessarily
indicate excessive emissions.)
Was the “On-Board Diagnostic (OBD) System Check”
performed?
—Go to Step 2
Go to OBD
System
Check
21. Perform a bulletin search.
2. If a bulletin that addresses the symptom is found,
correct the condition as instructed in the bulletin.
Was a bulletin found that addresses the symptom?
—Go to Step 12Go to Step 3
3Was a thorough visual/physical check performed?
—Go to Step 4
Go to
Visual/Physic
al Check
41. Check for vacuum leaks. Check vacuum lines,
intake manifold, throttle body, etc.
2. If a problem is found, repair as necessary.
Were any vacuum leaks located?
—Go to Step 12Go to Step 5
51. Check the fuel cap for proper installation.
2. Secure the fuel cap if necessary.
Was the fuel cap installed properly?
—Go to Step 6Go to Step 12
61. Check the fuel pressure. Perform the procedure in
Fuel System Pressure Test.
2. If a problem is found, repair as necessary.
Was a problem found?
—Go to Step 12Go to Step 7
71. Check for a faulty, plugged, or incorrectly installed
crankcase ventilation valve; also check the
crankcase ventilation system for plugging.
2. If a problem is found, repair as necessary.
Was a problem found?
—Go to Step 12Go to Step 8
81. Check the injector connections.
2. If any of the injectors are connected to an incorrect
cylinder, correct as necessary.
Was a problem found?
—Go to Step 12Go to Step 9
91. Perform the “Injector Coil/Balance Test” in Fuel
Metering System
.
2. If a problem is found, repair as necessary.
Was a problem found?
—Go to Step 12Go to Step 10
101. Refer to Engine Cooling for cooling system
diagnosis.
2. If a problem is found, repair as necessary.
Was a problem found?
—Go to Step 12Go to Step 11
111. Remove excessive carbon buildup with a top engine
cleaner. Refer to the instructions on the top engine
cleaner can.
2. Perform the exhaust emission test.
Does the vehicle pass the test?
—System OKGo to Step 13
12Perform the exhaust emission test.
Does the vehicle pass the test?
—System OKGo to Step 13

6E–280
ENGINE DRIVEABILITY AND EMISSIONS
Backfire Symptom
StepActionVa l u e ( s )Ye sNo
1DEFINITION:
Fuel ignites in the intake manifold, or in the exhaust
system, making a loud popping noise.
Was the “On-Board Diagnostic (OBD) System Check”
performed?
—Go to Step 2
Go to OBD
System
Check
21. Perform a bulletin search.
2. If a bulletin that addresses the symptom is found,
correct the condition as instructed in the bulletin.
Was a bulletin found that addresses the symptom?
—Verify repairGo to Step 3
3Was a visual/physical check performed?
—Go to Step 4
Go to
Visual/Physic
al Check
41. Check for proper ignition voltage coil output with
spark tester 5-8840-0383-0. Refer to
Electric
Ignition System
for procedure.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 5
51. Remove spark plugs and check for wet plugs,
cracks, wear, improper gap, burned electrodes, or
heavy deposits. Refer to
Electronic Ignition
System
.
NOTE: If spark plugs are gas or oil fouled, the cause of
the fouling must be determined before replacing the
spark plugs. Refer to
DTC P0172 to determine the
cause of a rich condition or
Engine Mechanical for an oil
fouling condition.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 6
61. Visually/physically inspect the ignition coils for
cracks.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 7
71. Check for an intermittent ignition system
malfunction:
Intermittent CKP 58X signal.
Intermittent ignition feed circuit or sensor
ground circuit to the crankshaft position
sensor.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 8
81. Check the fuel pressure. Refer to Fuel System
Pressure Test
.
2. If a problem is found, repair as necessary.
Was a problem found?
—Verify repairGo to Step 9