Suzuki outboard motors 1988 2003 repair manual., Page 108Get this manual
4-46 FUEL SYSTEM 2Crank the engine with the spark plugs removed and listen for the sound of the injector clicking3If there is no sound, then the injector is not operating and it will need to be replacedObtain the following special tool: Injector test cord(09930-99420)
It is not necessary to remove the injectors from the engine to perform this test4Crank the engine with the spark plugs removed and check the indicated voltageThe injector operating signal should indicate approximately 8-10 voltsDT225 (NO LOAD) Obtain the following special tool: 2-Pin connector test cord "B"(09930-89270) 1Turn the ignition switch to the OFF position2With the injectors installed on the engine, remove all six of the 2-pin connectorsConnect the 2-pin connector test cord between the injector being checked and the wiring harness as illustrated When inserting the 2-pin connector test cord connector, make sure the same color lead are connected together4Disconnect the injector wire and connect the test cord5Touch the stethoscope or screwdriver to the injector connector6Momentarily touch the red wire of the test cord to the starter motor relay left terminal (which is connected to the battery positive terminal) and listen for the sound of the injector clicking7If there is no sound, then the injector is not operating and it will need to be replacedDT225 (MULTIPLE INJECTORS) 1Obtain the following special tool to perform the test: 6-pin test harness (09930-89251)2Disconnect the 6-pin ECU connector containing blackyellow leads and install the test harness3Turn ignition switch to the ON position and touch one blacklyellow lead to groundListen for the sound of the injector clicking from injectors each time the blacklyellow lead is touched to groundThis means the injector is operating properlyRepeat the test for the other blacklyellow lead 3 injectors are controlled by each blackyellow ECU leadAnother way to tell if the injector is to place your finger on the injector itself and feel for the clicking motion inside the injector3Connect peak voltage meter (set on Positive 50V) as follows: Tester positive lead to the gray lead of the 2-pin connector test cord Tester negative lead to an engine ground 4If the tester indication is approximately 12 volts with the ignition switch in the ON position, the condition of the power system is normalIf the voltage is not as specified, check the following: Loose or discolored connectors Open circuits of the gray lead Disconnected connector or lead, failure of the main relay etc5Check the other five injectors in the same mannerDT225 (PEAK VOLT CHECK) Reform the first and second procedures of the previous power supply check (no load)2Connect the peak voltage meter (set on POSITIVE 50V) as follows: Tester positive lead to the blacklyellow lead of the 2-pin test connector cordTester negative lead to an engine ground3If the tester indication is approximately 12 volts with the ignition switch in the ON position, the operating condition is normal4Check for voltage with the engine being crankedIf more than approximately 20 volts is indicated during engine cranking, the injector control signal is normalIf the voltage being indicated is less than approximately 20 volts, check for connector looseness or the disconnection of the blacklyellow lead5Check the other five injectors in the same mannerIf less than 20 volts is indicated at all six injectors, perform an ECU power supply and ground checks Injector Resistance