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> Injector pulse help, Two are not firing
72914wrx
post Dec 11 2020, 10:13 PM
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Ok folks looking for a little help on my 914 74 914 2.0 car . I have two injectors not firing
2 and 3 . I’ve checked the fuel injection points at the bottom of the dissy they check out .
Check with a voltmeter and open and close on both sides . I then checked continuity for wires 21 12 and 22 going to the ecu . I found wires 12 and 22 switch when checking for continuity . The plug and been fixed years ago by looking at the repair. Switching the wires made no difference in injector firing still the same . The efi had just been gone though by a reputable shop that is well know just before I bought the car . The following work was done new intake boots , new injectors , rebuild manifold pressure sensor . Rebuilt ecu , new tigger point for injectors. . I’ve checked all grounds on the rear of the motor. To top this off the fuel pump stopped running but the relays are triggered. I need to check power down at the point . What I’m I missing ?
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JeffBowlsby
post Dec 11 2020, 10:35 PM
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Double/triple check the trigger points. 2 and 3 share a common switched circuit.
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72914wrx
post Dec 11 2020, 10:51 PM
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Ok will do but I have a question shouldn’t they also fire by moving the tps not running the other two do I have hear them and checked with a node light .
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JeffBowlsby
post Dec 12 2020, 01:14 AM
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Not sure I understand your question. You should hear all injectors click while rotating the TPS.
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72914wrx
post Dec 12 2020, 09:56 AM
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When the car is not running key on I move the tps and only have two injectors firing 1 and 4 . Could it still be the trigger points? Or is the tps out of adjustment?
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72914wrx
post Dec 12 2020, 10:02 AM
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I checked all injector grounds and they check out .
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JamesM
post Dec 12 2020, 10:02 AM
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QUOTE(72914wrx @ Dec 12 2020, 08:56 AM) *

When the car is not running key on I move the tps and only have two injectors firing 1 and 4 . Could it still be the trigger points? Or is the tps out of adjustment?


Check your grounds at the engine case. One wire of the injector is switched power from the ECU the other side is direct to ground.
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JamesM
post Dec 12 2020, 10:04 AM
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QUOTE(72914wrx @ Dec 12 2020, 09:02 AM) *

I checked all injector grounds and they check out .



Looks like we posted that at the same time. If grounds are good and wiring is good and you lost a single bank of injectors the issue is either the trigger points or the ECU.
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JamesM
post Dec 12 2020, 10:08 AM
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QUOTE(JamesM @ Dec 12 2020, 09:04 AM) *

QUOTE(72914wrx @ Dec 12 2020, 09:02 AM) *

I checked all injector grounds and they check out .



Looks like we posted that at the same time. If grounds are good and wiring is good and you lost a single bank of injectors the issue is either the trigger points or the ECU.

Given you said you tested the trigger points...

May want to try a different ECU. They rarely fail, but it does happen.
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72914wrx
post Dec 12 2020, 10:15 AM
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My suspect is the ecu at this point . It was rebuilt and run just fine when it left the shop last week Friday when we bought it Sunday I knew right away something was wrong. He had an invoice of 4K of parts and labor and the trigger points are new and the ecu was rebuilt.
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JeffBowlsby
post Dec 12 2020, 01:24 PM
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How are you rotating the TPS? But loosening the two screws and rotating its body, or by moving the throttle plate?
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72914wrx
post Dec 12 2020, 01:33 PM
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My moving the throttle plate pulling basically the cable / lever . This should by pass the trigger points no ?
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72914wrx
post Dec 12 2020, 11:39 PM
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Ok I believe I found my problem the driver is out on the ecu for injectors 2 and 3 . Not sure if that’s D1 or D2 driver . After spending more of the day checking wires and grounds I have an answer to my problem. I now hoping
That the vender that rebuild the ecu will stand behind it !
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