Does anybody have an idea where I can look next? I tested the injector and have 1.5 ohms, it has fire, fuel pump is working with what seems to be plenty of pressure bto the back of the throttle body, fuel filter is new and in the right flow direction. Is there a relay or fuse for the fuel injection? It does run when I dump fuel in the throttle body. I changed the crank trigger, ignition module and computer. Thanks in advance, John
Here is some info. Disconnect the injector wire connector from the injector.
Place an ohmmeter on the injector terminals.
Resistance reading should be approximately 1.2 Ohms .
The DRB II and Jeep/Eagle adapter can be used to determine certain fault codes in the injector circuit. To read fault codes "SYSTEM TESTS" must be selected from the main menu. The DRB II screens will provide instructions to prompt the technician through a series of functional tests. Any fault codes will be displayed on the DRB II screen.
Fault code number 1012 indicates the fuel injector crcuits require testing. Possible problems include an open in the injector voltage supply wire from the fuel pump relay, an open in the injector control wire, the injector control wire shorted to ground, a faulty fuel injector or ECU.
Your Vehicle: 1989 Jeep Truck Wrangler L4-150 2.5L VIN E TBI
Vehicle » Powertrain Management » Fuel Delivery and Air Induction » Fuel Pump Relay » Testing and Inspection Notes
Testing and Inspection
Relay Terminal Identification
FUEL PUMP RELAY TERMINAL IDENTIFICATION
The following is a list of the terminal numbers, with circuit codes, and color codes, and their function:
Circuit No. Terminal No. Color Code Description
10 30 Red Has battery input voltage supplied through fusible link.
F22 87 Orange Connected to 10 circuit (terminal 30) in the energized position, supplies output voltage to fuel pump, EGR/EVAP solenoid, and fuel injectors.
F17 86 Orange Connected to the Electronic Control Unit (ECU), which provides input voltage to the relay.
11 85 Yellow Connected to the ECU, and grounded by the ECU when distributor signal is present.
N/A 87A N/A Not used in these applications.
FUEL PUMP RELAY TEST
NOTE: The Fuel Pump relay operation may be tested with the use of the DRB II scanner or equivalent. Refer to COMPUTERIZED ENGINE CONTROLS/DIAGNOSIS AND TESTING for procedure. If no scanner is available proceed with the following test.
Connect a voltmeter to the 10 (terminal 30) wire at the fuel pump relay connector. Check for battery voltage. If no voltage is present, check fusible links and supply voltage from the battery. If voltage is present proceed to step 2.
Connect the voltmeter to the F22 (terminal 87) wire at the fuel pump relay connector. Turn the ignition key to the START position and crank the engine. If output voltage is present during cranking, the fuel pump relay is functioning normally and no further testing of the fuel pump relay is necessary. If no voltage is present at the F22 wire, proceed to step 3.
Connect the voltmeter to the F17 (terminal 86) wire at the fuel pump relay connector. Turn the ignition key to the RUN position. Input voltage from the ECU to the fuel pump relay should be present. If voltage is present proceed to step 4. If no voltage is present, disconnect the 35 way ECU and 6 way diagnostic connectors, and the fuel pump relay connector. Connect an ohmmeter between the F17 (terminal 86) wire and the orange wire at pin connector no. 6 of the ECU, and check for continuity. If continuity exists, refer to COMPUTERIZED ENGINE CONTROLS/DIAGNOSIS AND TESTING for ECU testing procedures. If no continuity exists, repair open in wire, reconnect ECU and fuel pump relay, and test operation.
Connect voltmeter to 11 (terminal 85) wire at fuel pump relay connector. Turn ignition key to START position, and crank engine, while observing voltage at 11. Voltage should be present at 11 and drop to less than 1 volt within 2 seconds during cranking. If voltage drops fuel pump relay is functioning, and no further testing of the fuel pump relay is necessary. If voltage does not drop, proceed to step 5. If no voltage is present, disconnect the fuel pump relay, and connect an ohmmeter between the F17 (terminal 86) and 11 (terminal 85) of the fuel pump relay and check for continuity. If no continuity exists replace the fuel pump relay and test operation.
Disconnect the 35 way ECU, and 6 way diagnostic connectors and fuel pump relay. Connect an ohmmeter between the 11 wire at the fuel pump relay connector and the yellow wire at pin connector no. 3 of the ECU. Check for continuity. If no continuity exists repair open in wire, reconnect ECU and fuel pump relay, and test operation. If continuity exists, refer to COMPUTERIZED ENGINE CONTROLS/DIAGNOSIS AND TESTING , for ECU testing procedures.
I retested the injector and have 1.3 ohms. I changed the ECU with a good one from a running donar vehicle. The fuel pump kicks on every time you cycle the ignition (key) on, I loosened the fuel line on the back of the throttle body and when I turn the engine over I have plenty of fuel squirting out.
we had a very similar problem! Hubby talked to a friend of ours who knows the 2.5 in and out and he said either map sensor or ecu. After replacing many parts it wound up being the ecu like he said. Do you have a map sensor you can try? Ours is also the 89 2.5 fuel injected...
I just replaced three relay's rather than testing each one. Two near the battery and one under the driver side dash on front left. I don't have a map sensor but I'm sure one of the auto part chains will. Thanks, John
Alright to all who are interested, I now have changed the map sensor and it still has no injector pulse. Have I missed changing something that would control injector pulse? And no, I don't like spending money on parts that don't need to be changed, I just figured 10 for a relay (x3), 20 for trigger, 40 for a sensor, what could it hurt as long as it worked.
did any one mention the possibility of ignition control module yet, if not might be something to look into. next so u have no pulse can u trace the wires back and see if theirs a connector that may be loose or corroded. and also check the wire to see if theirs voltage farther down the line.
some say why i say
its a jeep thing u wouldn't understand
Just so everyone knows that the Jeep was running when parked one month ago, I went out to start it and the start of this thread explains my problem and what I've done so far, but just to clarify I've changed the: crank trigger, map sensor, ignition control module, ECU, both relay's by the battery, one relay in cab on drivers side, there is good fuel pressure to the throttle body and the injector resistence is approximately 1.3 ohms. It has to be something simple, but I'm so fustrated that I'm about ready to change the distrbutor and throttle body to a carb.
Have you tried replacing the injector itself? They are a little pricy new 125 rebuilt around 65 and junkyard (the route we took) 15. Had to go to 4 different yards before we finally found one in a 4.3 liter jimmy.
For all who are interested, it was an injector problem. It tested good (ohms/voltage) but wouldn't pulse fuel, not a drop. It must have gotten stuck or something. Got a used injector from a local yard out of an 88 chevy impala brouham with two injectors in a throttle body on top of a 4.3L, runs better than ever!! THANKS FOR ALL THE INPUT.
I am having a very similar problem. My 90 2.5L will run on starting fluid but will not fire on it's own. There is a steady stream of fuel to the throttle body and the spark is strong. I too replaced my injector and it DID NOT solve my problem. I am thinking it could be the ECU or wiring from the ECU to the injector. Anyone got any ideas??