1、Designation: D 6421 99a (Reapproved 2004)An American National StandardStandard Test Method forEvaluating Automotive Spark-Ignition Engine Fuel forElectronic Port Fuel Injector Fouling by Bench Procedure1This standard is issued under the fixed designation D 6421; the number immediately following the
2、designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers a
3、 bench test procedure toevaluate the tendency of automotive spark-ignition engine fuelto foul electronic port fuel injectors (PFI). The test methodutilizes a bench apparatus equipped with Bosch injectorsspecified for use in a 1985-1987 Chrysler 2.2-L turbochargedengine. This test method is based on
4、a test procedure developedby the Coordinating Research Council (CRC) for prediction ofthe tendency of spark-ignition engine fuel to form deposits inthe small metering clearances of injectors in a port fuelinjection engine (see CRC Report No. 5922).1.2 The test method is applicable to spark-ignition
5、enginefuels, which may contain antioxidants, corrosion inhibitors,metal deactivators, dyes, deposit control additives, demulsifi-ers, or oxygenates, or a combination thereof.1.3 The values stated in SI units are to be regarded as thestandard. Approximate inch-pound units are shown in paren-theses fo
6、r information purposes only.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations
7、prior to use. Specific precau-tionary statements are given throughout this test method.NOTE 1If there is any doubt as to the latest edition of Test MethodD 6421, contact ASTM International Headquarters. Other properties ofsignificance to spark-ignition engine fuel are described in SpecificationD 481
8、4.2. Referenced Documents2.1 ASTM Standards:3D 4814 Specification forAutomotive Spark-Ignition EngineFuelD 5598 Test Method for Evaluating Unleaded AutomotiveSpark-Ignition Engine Fuel for Electronic Port Fuel Injec-tor Fouling2.2 ANSI Standard:4MC 96.1 American National Standard for TemperatureMeas
9、urement Thermocouples.2.3 CARB Standard:5Test Method for Evaluating Port Fuel Injector (PFI) De-posits in Vehicle Engines2.4 Clean Air Act Amendment:6Clean Air Act Amendments of 1990, Public Law 101549,Title 1 Provisions for Attainment and Maintenance ofNational Air Quality Standards3. Terminology3.
10、1 Definitions of Terms Specific to This Standard:3.1.1 base fuel, nunleaded automotive spark-ignition en-gine fuel that does not contain a deposit control additive butmay contain antioxidants, corrosion inhibitors, metal deactiva-tors, dyes, or oxygenates, or a combination thereof.3.1.2 cycle, na 15
11、-s pulsing period, followed by a 50-minheating period at 160C (320F), followed by a 10-mincool-down period.3.1.3 deposit control additive, nmaterial added to the basefuel to prevent or remove deposits in the entire engine intakesystem.3.1.3.1 DiscussionFor the purposes of this test method,the perfor
12、mance of a deposit control additive is limited to theelectronic PFI tip areas.3.1.4 driveability, nthe quality of a vehicles performancecharacteristics as perceived by the operator in response tochanges in throttle position.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleu
13、m Products and Lubricants and is the direct responsibility of SubcommitteeD02.A0 on Gasoline and Oxygenated Fuels.Current edition approved July 1, 2004. Published July 2004. Originally approvedin 1999. Last previous edition approved in 1999 as D 6421 99a.2“A Program to Evaluate a Bench Scale Test Me
14、thod to Determine the DepositForming Tendencies of Port Fuel Injectors,” available from Coordinating ResearchCouncil, Inc., 219 Perimeter Ctr. Pkwy., Atlanta, GA 30346.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual
15、 Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.4Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036.5Available from California Air Resources Board, P.O. Box 2815, Sacramento,CA 95815. (I
16、ncorporated by reference in California Code of Regulations, Title 13,Section 2257.)6Available from Superintendent of Documents, U.S. Government PrintingOffice, Washington, D.C. 20402.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.
17、1.5 electronic port fuel injector (PFI), nan electrome-chanical device used to control fuel flow in an internalcombustion engine.3.1.6 fouling, vformation of carbonaceous deposits on thepintle or metering surfaces of an electronic fuel injector, whichreduces fuel flow rate.3.1.7 pintle, na needle-li
18、ke metering device extendingbeyond the electronic fuel injector body that is part of anelectronic fuel injector, which controls flow rate and spraypattern.3.1.8 test fuel, nbase fuel, with or without the addition ofa deposit control additive, that is used for evaluation asdescribed in this test meth
19、od.4. Summary of Test Method4.1 This test method describes a procedure for evaluatingthe formation of deposits in PFIs. The test method includes abench test procedure that has been shown to rapidly formdeposits in fuel injectors and a procedure for determiningresultant flow loss.4.2 This test method
20、 uses a simulated fuel system consistingof a fuel pump, filter, pressure regulator, fuel rail, and fuelinjectors. A heat source is applied to the fuel injectors tosimulate the hot-soak portion of the vehicle test (see TestMethod D 5598).4.3 Each test begins with screened injectors that are knownto f
21、oul. The tips of these four clean fuel injectors are placed inan aluminum block. A stainless-steel internal reservoir is filledwith 2 L of the test fuel.4.4 During one 60-min test cycle, the fuel injectors arepulsed for 15 s, followed by a 50-min hot-soak interval inwhich the injector aluminum block
22、 temperature controller is setat a temperature of 160C (320F) and the fuel pressure isregulated to 263 kPa (38 psig), followed by a 10-min cool-down period. Flow measurements for each of the injectors aretaken at the beginning of the test, after 22 cycles, and at the endof the test at 44 cycles.4.5
23、The change in the rate of flow for each injector from thestart to the end of the test is used to determine the foulingpercentage of each injector.5. Significance and Use5.1 Driveability problems in PFI automobiles were firstreported in 1984. Deposits are prone to form on the meteringsurfaces of pint
24、le-type electronic fuel injectors. These depositsreduce fuel flow through the metering orifices. Reductions inmetered fuel flow result in an upset in the air-fuel ratio, whichcan affect emissions and driveability. When heavy enough,these deposits can lead to driveability symptoms, such ashesitation,
25、 hard starting, or loss of power, or a combinationthereof, that are easily noticed by the average driver and thatlead to customer complaints. The mechanism of the formationof deposits is not completely understood. It is believed to beinfluenced by many factors, including driving cycle, engineand inj
26、ector design, and composition of the fuel. The procedurein this test method has been found to build deposits in PFIs ona consistent basis. This procedure can be used to evaluatedifferences in base fuels and fuel additives. A study of PFIfouling was conducted in both the bench test and the vehicletes
27、t procedures to obtain a correlation. The vehicle tests wereconducted as described in Test Method D 5598. The tests wereconducted on several base gasolines, with and without addi-tives blended into these base fuels. The PFI bench test provedto be reliable, repeatable, and a good predictor of PFI fou
28、lingin test vehicles.5.1.1 State and Federal Legislative and RegulatoryActionLegislative and regulatory activity, primarily by thestate of California (see 2.3) and the federal government (see2.4), necessitate the acceptance of a standard test method toevaluate the PFI deposit-forming tendency of an
29、automotivespark-ignition engine fuel.5.1.2 Relevance of ResultsThe operating conditions anddesign of the laboratory apparatus used in this test method maynot be representative of a current vehicle fuel system. Thesefactors must be considered when interpreting results.5.2 Test Validity:5.2.1 Procedur
30、al ComplianceThe test results are not con-sidered valid unless the test is completed in compliance with allrequirements of this test method. Deviations from the param-eter limits presented in Section 10 will result in an invalid test.Engineering judgment shall be applied during conduct of thetest me
31、thod when assessing any anomalies to ensure validity ofthe test results.6. Apparatus6.1 Automatic Electronic PFI Bench Test Apparatus7Thisapparatus is composed of two units, a fuel handling unit and acontroller.6.1.1 Fuel Handling UnitThis unit houses a machinedaluminum fuel rail and a heated alumin
32、um block designed toaccommodate four PFIs. Heaters and thermocouples aremounted in the heated aluminum block. This unit also housesa 2.25-L stainless steel reservoir, an electric fuel pump, a fuelregulator, and a variety of valves used to transfer fuel to andfrom the reservoir and to deliver fuel un
33、der pressure to theinjectors (see Annex A1).6.1.2 Programmable Microprocessor Controller or OtherControllerThe controller is used to fill the fuel reservoir,control and measure the temperature of the heated block, pulsethe injectors, control the soak period, count the number of testcycles, and contr
34、ol the flow period for the measuring of theflow rate. The unit is programmed to shut down automaticallyat the end of each 22-cycle period.6.1.3 External Pressure RegulatorThis regulator is usedto adjust the pressure of the nitrogen gas on the fuel system.This ensures that the pressure of the fuel in
35、 the fuel rail ismaintained with an accuracy of 66.8 kPa (61.0 psi) during thetest.6.1.4 Electronic PFIsOnly Bosch EV1.1A (Part Number0280150360) pintle-style injectors shall be used.8,9The corre-sponding Chrysler Corp. part number is 4306024 and is clearlymarked on the injector. The protective cap
36、shall be removed7The following instrument has been found suitable by interlaboratory coopera-tive testing: Port Fuel Injector Bench Test Apparatus. Available from SouthwestResearch Institute, San Antonio, TX.8The sole source of supply of the pintle-style injectors known to the committeeat this time
37、is Robert Bosch Corp., 25thAve., Broadview, IL 60153.D 6421 99a (2004)2from the injector by cutting the plastic cap with a razor bladeand gently heating with a heat gun. The rubber o-rings andspacers shall be removed to expose the bare metal injector tip.Each injector shall be screened for fouling c
38、apability prior touse in the procedure. The screening procedure is found inAnnex A2.6.2 Testing AreaThe ambient atmosphere of the testingarea shall be reasonably free of contaminants. The temperatureshould be maintained at 24 6 5C (75 6 9F). Uniformtemperature is necessary to ensure repeatable injec
39、tor flowmeasurements. The specific humidity shall be maintained at auniform comfortable level. (WarningProvide adequate ven-tilation and fire protection in areas where flammable or volatileliquids and solvents, or both, are used. Suitable protectiveclothing is recommended.)6.3 Laboratory Equipment:6
40、.3.1 Analytical BalanceAn analytical balance capable of0.01 g resolution with a maximum capacity of at least 200 g isrecommended. The balance should be calibrated following themanufacturers procedure and frequency recommendations.6.3.2 Graduated CylindersFour graduated cylinders of 50or 100-mL capac
41、ity, accurate to the nearest millilitre arerecommended for use in flow testing.6.3.3 Low Voltage Power SupplyA 12 V, variable, directcurrent power source should be used in cleaning of theinjectors.6.3.4 Ultrasonic BathAn ultrasonic bath with heatingcapabilities should be used for the cleaning of the
42、 injectors.6.3.5 Pipette BulbA pipette bulb should be used to drawinjector cleaning solution into the injector for cleaning.6.3.6 PipetteA disposable transfer pipette should be usedto fill injectors with the cleaning solution during the cleaningprocedure.6.3.7 Plastic Disposable BeakersDisposable pl
43、astic bea-kers of approximately 150 mLor other containers of equivalentsize should be used to contain the injector cleaning fluid duringthe clean up of the injectors.6.4 Data AcquisitionAdata acquisition device, capable ofcollecting the raw data in accordance with 10.4, shall berequired.7. Reagents
44、and Materials7.1 Purity of ReagentsReagent grade chemicals shall beused for all test procedures. Unless otherwise noted, it isintended that all reagents conform to the specifications of theCommittee on Analytical Reagents of the American ChemicalSociety, where such specifications are available.10Oth
45、er gradesmay be used provided it is first ascertained that the reagent isof sufficient purity to permit its use without lessening theaccuracy of the determinations.7.2 Berryman Chem-Dip Carburetor and PartsCleaner11,9This cleaner has been found effective in remov-ing the deposits built up in the inj
46、ectors. This cleaner or anyother carburetor or engine parts cleaner that is proven effectivein removing such deposits shall be used to clean the injectors.(WarningBerryman Chem-Dip contains methylene chlo-ride, monochlorotoluene, xylene, ethyl phenols, and xylenolsthat are extremely dangerous if inh
47、aled, are skin irritant oncontact, and are carcinogenic.)7.3 Rinsing SolventA 1:1 mixture of isooctane and xy-lene, or suitable mixture of solvents, shall be used to rinse thebench test apparatus reservoir, injectors, and fuel lines betweentests. Approximately 1 L is used.7.4 Test FuelA test fuel is
48、 either a base fuel or ahomogeneous blend of additives and base fuel. A single batchshall be blended before the start of the test. Approximately 8 L(2 gal) of fuel is needed for a single test.7.5 Additive/Base FuelSome test requestors may requirethat the test fuel be blended at the test laboratory a
49、nd, therefore,will supply the deposit control additive and may, at their optionor if a suitable base fuel is not available at the test laboratory,supply untreated base fuel. The test requestor shall supply thedeposit control additive and, if supplied, the base fuel inappropriate volumes and packaging to ensure safe and efficienthandling. Blending instructions detailing the concentrationratio either volumetric-based or mass-based shall accompanyall deposit control additives. Mass-based measurement ispreferred. The blended fuel shall be clea
