ASTM D6421-99a(2009)
(Test Method)Standard Test Method for Evaluating Automotive Spark-Ignition Engine Fuel for Electronic Port Fuel Injector Fouling by Bench Procedure
Standard Test Method for Evaluating Automotive Spark-Ignition Engine Fuel for Electronic Port Fuel Injector Fouling by Bench Procedure
SIGNIFICANCE AND USE
Driveability problems in PFI automobiles were first reported in 1984. Deposits are prone to form on the metering surfaces of pintle-type electronic fuel injectors. These deposits reduce fuel flow through the metering orifices. Reductions in metered fuel flow result in an upset in the air-fuel ratio, which can affect emissions and driveability. When heavy enough, these deposits can lead to driveability symptoms, such as hesitation, hard starting, or loss of power, or a combination thereof, that are easily noticed by the average driver and that lead to customer complaints. The mechanism of the formation of deposits is not completely understood. It is believed to be influenced by many factors, including driving cycle, engine and injector design, and composition of the fuel. The procedure in this test method has been found to build deposits in PFIs on a consistent basis. This procedure can be used to evaluate differences in base fuels and fuel additives. A study of PFI fouling was conducted in both the bench test and the vehicle test procedures to obtain a correlation. The vehicle tests were conducted as described in Test Method D5598. The tests were conducted on several base gasolines, with and without additives blended into these base fuels. The PFI bench test proved to be reliable, repeatable, and a good predictor of PFI fouling in test vehicles.
State and Federal Legislative and Regulatory Action—Legislative and regulatory activity, primarily by the state of California (see 2.3) and the federal government (see 2.4), necessitate the acceptance of a standard test method to evaluate the PFI deposit-forming tendency of an automotive spark-ignition engine fuel.
Relevance of Results—The operating conditions and design of the laboratory apparatus used in this test method may not be representative of a current vehicle fuel system. These factors must be considered when interpreting results.
Test Validity:
Procedural Compliance—The test results are not considered val...
SCOPE
1.1 This test method covers a bench test procedure to evaluate the tendency of automotive spark-ignition engine fuel to foul electronic port fuel injectors (PFI). The test method utilizes a bench apparatus equipped with Bosch injectors specified for use in a 1985-1987 Chrysler 2.2-L turbocharged engine. This test method is based on a test procedure developed by the Coordinating Research Council (CRC) for prediction of the tendency of spark-ignition engine fuel to form deposits in the small metering clearances of injectors in a port fuel injection engine (see CRC Report No. 592).
1.2 The test method is applicable to spark-ignition engine fuels, which may contain antioxidants, corrosion inhibitors, metal deactivators, dyes, deposit control additives, demulsifiers, or oxygenates, or a combination thereof.
1.3 The values stated in SI units are to be regarded as the standard. Approximate inch-pound units are shown in parentheses for information purposes only.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Specific precautionary statements are given throughout this test method.
Note 1—If there is any doubt as to the latest edition of Test Method D6421, contact ASTM International Headquarters. Other properties of significance to spark-ignition engine fuel are described in Specification D4814.
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D6421 − 99a(Reapproved 2009)
Standard Test Method for
Evaluating Automotive Spark-Ignition Engine Fuel for
Electronic Port Fuel Injector Fouling by Bench Procedure
This standard is issued under the fixed designation D6421; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2. Referenced Documents
1.1 This test method covers a bench test procedure to 2.1 ASTM Standards:
evaluate the tendency of automotive spark-ignition engine fuel D4814Specification for Automotive Spark-Ignition Engine
to foul electronic port fuel injectors (PFI). The test method Fuel
utilizes a bench apparatus equipped with Bosch injectors D5598Test Method for Evaluating Unleaded Automotive
specified for use in a 1985-1987 Chrysler 2.2-L turbocharged Spark-IgnitionEngineFuelforElectronicPortFuelInjec-
engine.Thistestmethodisbasedonatestproceduredeveloped tor Fouling
by the Coordinating Research Council (CRC) for prediction of 2.2 ANSI Standard:
the tendency of spark-ignition engine fuel to form deposits in MC96.1AmericanNationalStandardforTemperatureMea-
the small metering clearances of injectors in a port fuel surement Thermocouples
2 5
injection engine (see CRC Report No. 592). 2.3 CARB Standard:
Test Method for Evaluating Port Fuel Injector (PFI) Depos-
1.2 The test method is applicable to spark-ignition engine
its in Vehicle Engines
fuels, which may contain antioxidants, corrosion inhibitors,
2.4 Clean Air Act Amendment:
metal deactivators, dyes, deposit control additives,
Clean Air Act Amendments of 1990, Public Law 101–549,
demulsifiers, or oxygenates, or a combination thereof.
Title 1 –Provisions for Attainment and Maintenance of
1.3 The values stated in SI units are to be regarded as the
National Air Quality Standards
standard. Approximate inch-pound units are shown in paren-
3. Terminology
theses for information purposes only.
1.4 This standard does not purport to address all of the 3.1 Definitions of Terms Specific to This Standard:
3.1.1 base fuel, n—unleaded automotive spark-ignition en-
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- gine fuel that does not contain a deposit control additive but
may contain antioxidants, corrosion inhibitors, metal
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. Specific precau- deactivators, dyes, or oxygenates, or a combination thereof.
tionary statements are given throughout this test method.
3.1.2 cycle, n—a 15-s pulsing period, followed by a 50-min
heating period at 160°C (320°F), followed by a 10-min
NOTE 1—If there is any doubt as to the latest edition of Test Method
cool-down period.
D6421, contact ASTM International Headquarters. Other properties of
significance to spark-ignition engine fuel are described in Specification
D4814.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
This test method is under the jurisdiction of ASTM Committee D02 on the ASTM website.
PetroleumProductsandLubricantsandisthedirectresponsibilityofSubcommittee Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
D02.A0.01 on Gasoline and Gasoline-Oxygenate Blends. 4th Floor, New York, NY 10036, http://www.ansi.org.
Current edition approved June 1, 2009. Published November 2009. Originally Available from California Air Resources Board, P.O. Box 2815, Sacramento,
approved in 1999. Last previous edition approved in 2004 as D6421–99a (2004). CA95815. (Incorporated by reference in California Code of Regulations, Title 13,
DOI: 10.1520/D6421-99AR09. Section 2257.)
2 6
“AProgram to Evaluate a Bench Scale Test Method to Determine the Deposit AvailablefromU.S.GovernmentPrintingOfficeSuperintendentofDocuments,
Forming Tendencies of Port Fuel Injectors,” available from Coordinating Research 732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401, http://
Council, Inc., 219 Perimeter Ctr. Pkwy., Atlanta, GA 30346. www.access.gpo.gov.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6421 − 99a (2009)
3.1.3 deposit control additive, n—materialaddedtothebase can affect emissions and driveability. When heavy enough,
fuel to prevent or remove deposits in the entire engine intake these deposits can lead to driveability symptoms, such as
system. hesitation, hard starting, or loss of power, or a combination
3.1.3.1 Discussion—For the purposes of this test method, thereof, that are easily noticed by the average driver and that
the performance of a deposit control additive is limited to the lead to customer complaints. The mechanism of the formation
electronic PFI tip areas. of deposits is not completely understood. It is believed to be
influenced by many factors, including driving cycle, engine
3.1.4 driveability, n—the quality of a vehicle’s performance
andinjectordesign,andcompositionofthefuel.Theprocedure
characteristics as perceived by the operator in response to
in this test method has been found to build deposits in PFIs on
changes in throttle position.
a consistent basis. This procedure can be used to evaluate
3.1.5 electronic port fuel injector (PFI), n—an electrome-
differences in base fuels and fuel additives. A study of PFI
chanical device used to control fuel flow in an internal
fouling was conducted in both the bench test and the vehicle
combustion engine.
test procedures to obtain a correlation. The vehicle tests were
3.1.6 fouling, v—formation of carbonaceous deposits on the
conducted as described in Test Method D5598. The tests were
pintleormeteringsurfacesofanelectronicfuelinjector,which
conducted on several base gasolines, with and without addi-
reduces fuel flow rate.
tives blended into these base fuels. The PFI bench test proved
3.1.7 pintle, n—a needle-like metering device extending to be reliable, repeatable, and a good predictor of PFI fouling
in test vehicles.
beyond the electronic fuel injector body that is part of an
electronic fuel injector, which controls flow rate and spray 5.1.1 State and Federal Legislative and Regulatory
Action—Legislative and regulatory activity, primarily by the
pattern.
state of California (see 2.3) and the federal government (see
3.1.8 test fuel, n—base fuel, with or without the addition of
2.4), necessitate the acceptance of a standard test method to
a deposit control additive, that is used for evaluation as
evaluate the PFI deposit-forming tendency of an automotive
described in this test method.
spark-ignition engine fuel.
4. Summary of Test Method 5.1.2 Relevance of Results—The operating conditions and
designofthelaboratoryapparatususedinthistestmethodmay
4.1 This test method describes a procedure for evaluating
not be representative of a current vehicle fuel system. These
the formation of deposits in PFIs. The test method includes a
factors must be considered when interpreting results.
bench test procedure that has been shown to rapidly form
deposits in fuel injectors and a procedure for determining 5.2 Test Validity:
resultant flow loss. 5.2.1 Procedural Compliance—The test results are not con-
sideredvalidunlessthetestiscompletedincompliancewithall
4.2 Thistestmethodusesasimulatedfuelsystemconsisting
requirements of this test method. Deviations from the param-
of a fuel pump, filter, pressure regulator, fuel rail, and fuel
eterlimitspresentedinSection10willresultinaninvalidtest.
injectors. A heat source is applied to the fuel injectors to
Engineering judgment shall be applied during conduct of the
simulate the hot-soak portion of the vehicle test (see Test
testmethodwhenassessinganyanomaliestoensurevalidityof
Method D5598).
the test results.
4.3 Each test begins with screened injectors that are known
to foul.The tips of these four clean fuel injectors are placed in 6. Apparatus
an aluminum block.Astainless-steel internal reservoir is filled 7,8
6.1 Automatic Electronic PFI Bench Test Apparatus —
with 2 L of the test fuel.
This apparatus is composed of two units, a fuel handling unit
4.4 During one 60-min test cycle, the fuel injectors are and a controller.
pulsed for 15 s, followed by a 50-min hot-soak interval in 6.1.1 Fuel Handling Unit—This unit houses a machined
whichtheinjectoraluminumblocktemperaturecontrollerisset aluminum fuel rail and a heated aluminum block designed to
at a temperature of 160°C (320°F) and the fuel pressure is accommodate four PFIs. Heaters and thermocouples are
regulated to 263 kPa (38 psig), followed by a 10-min cool- mounted in the heated aluminum block. This unit also houses
down period. Flow measurements for each of the injectors are
a 2.25-L stainless steel reservoir, an electric fuel pump, a fuel
takenatthebeginningofthetest,after22cycles,andattheend regulator, and a variety of valves used to transfer fuel to and
of the test at 44 cycles.
from the reservoir and to deliver fuel under pressure to the
injectors (see Annex A1).
4.5 Thechangeintherateofflowforeachinjectorfromthe
6.1.2 Programmable Microprocessor Controller or Other
start to the end of the test is used to determine the fouling
Controller—The controller is used to fill the fuel reservoir,
percentage of each injector.
controlandmeasurethetemperatureoftheheatedblock,pulse
5. Significance and Use
5.1 Driveability problems in PFI automobiles were first
The following instrument has been found suitable by interlaboratory coopera-
tive testing: Port Fuel Injector Bench Test Apparatus. Available from Southwest
reported in 1984. Deposits are prone to form on the metering
Research Institute, San Antonio, TX.
surfaces of pintle-type electronic fuel injectors.These deposits
If you are aware of alternative suppliers, please provide this information to
reduce fuel flow through the metering orifices. Reductions in
ASTM International Headquarters. Your comments will receive careful consider-
metered fuel flow result in an upset in the air-fuel ratio, which ation at a meeting of the responsible technical committee, which you may attend.
D6421 − 99a (2009)
the injectors, control the soak period, count the number of test 7.1 Purity of Reagents—Reagent grade chemicals shall be
cycles, and control the flow period for the measuring of the used for all test procedures. Unless otherwise noted, it is
flow rate. The unit is programmed to shut down automatically intended that all reagents conform to the specifications of the
at the end of each 22-cycle period. Committee onAnalytical Reagents of theAmerican Chemical
6.1.3 External Pressure Regulator —This regulator is used Society,wheresuchspecificationsareavailable. Othergrades
to adjust the pressure of the nitrogen gas on the fuel system. may be used provided it is first ascertained that the reagent is
This ensures that the pressure of the fuel in the fuel rail is of sufficient purity to permit its use without lessening the
maintainedwithanaccuracyof 66.8kPa(61.0psi)duringthe accuracy of the determinations.
test.
7.2 Berryman Chem-Dip Carburetor and Parts
8,11
6.1.4 Electronic PFIs—Only Bosch EV1.1A (Part Number
Cleaner —Thiscleanerhasbeenfoundeffectiveinremoving
8,9
0280150360) pintle-style injectors shall be used. The corre-
the deposits built up in the injectors. This cleaner or any other
spondingChryslerCorp.partnumberis4306024andisclearly
carburetor or engine parts cleaner that is proven effective in
marked on the injector. The protective cap shall be removed
removing such deposits shall be used to clean the injectors.
from the injector by cutting the plastic cap with a razor blade
(Warning—Berryman Chem-Dip contains methylene chlo-
and gently heating with a heat gun. The rubber o-rings and
ride, monochlorotoluene, xylene, ethyl phenols, and xylenols
spacers shall be removed to expose the bare metal injector tip.
that are extremely dangerous if inhaled, are skin irritant on
Each injector shall be screened for fouling capability prior to
contact, and are carcinogenic.)
use in the procedure. The screening procedure is found in
7.3 Rinsing Solvent—A1:1mixtureofisooctaneandxylene,
Annex A2.
orsuitablemixtureofsolvents,shallbeusedtorinsethebench
6.2 Testing Area—The ambient atmosphere of the testing
test apparatus reservoir, injectors, and fuel lines between tests.
areashallbereasonablyfreeofcontaminants.Thetemperature
Approximately 1 L is used.
should be maintained at 24 6 5°C (75 6 9°F). Uniform
7.4 Test Fuel—A test fuel is either a base fuel or a
temperature is necessary to ensure repeatable injector flow
homogeneous blend of additives and base fuel.Asingle batch
measurements. The specific humidity shall be maintained at a
shallbeblendedbeforethestartofthetest.Approximately8L
uniform comfortable level. (Warning —Provide adequate
(2 gal) of fuel is needed for a single test.
ventilation and fire protection in areas where flammable or
7.5 Additive/Base Fuel—Some test requestors may require
volatile liquids and solvents, or both, are used. Suitable
thatthetestfuelbeblendedatthetestlaboratoryand,therefore,
protective clothing is recommended.)
willsupplythedepositcontroladditiveandmay,attheiroption
6.3 Laboratory Equipment:
or if a suitable base fuel is not available at the test laboratory,
6.3.1 Analytical Balance—An analytical balance capable of
supply untreated base fuel. The test requestor shall supply the
0.01 g resolution with a maximum capacity of at least 200 g is
deposit control additive and, if supplied, the base fuel in
recommended. The balance should be calibrated following the
appropriatevolumesandpackagingtoensuresafeandefficient
manufacturer’s procedure and frequency recommendations.
handling. Blending instructions detailing the concentration
6.3.2 Graduated Cylinders—Fourgraduatedcylindersof50
ratio either volumetric-based or mass-based shall accompany
or 100-mL capacity, accurate to the nearest millilitre are
all deposit control additives. Mass-based measurement is
recommended for use in flow testing.
preferred. The blended fuel shall be clearly identified.
6.3.3 Low Voltage Power Supply—A 12 V, variable, direct
7.5.1 Additive/Base Fuel Shipment and Storage—The addi-
current power source should be used in cleaning of the
tive shall be shipped in a container as dictated by safety and
injectors.
environmental regulations. The additive shall be stored in
6.3.4 Ultrasonic Bath—An ultrasonic bath with heating
accord
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