 Testing power to ECU question., Fuel pump |
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| 74ravenna |
 Feb 14 2016, 12:45 PM
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#1
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Member  Group: Members Posts: 472 Joined: 19-October 14 From: nh Member No.: 18,032 Region Association: North East States 
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Hi,
In trying to figure why I can't start my 74 1.8 i decided to try the attached troubleshooting guide and hopefully learn about my car. First off I have never heard the fuel pump run like everyone speaks of but I do have fuel after the pump and in the engine bay lines so I believe it works. So i get to test #9 on the attached sequence, i unplug the ECU then go inside the car to turn the ignition on and the pump starts running and doesn't seem to want to stop. The sound is unmistakable and I know this is the first time I've heard it. Not wanting to check for 12V. at pins 16 & 24 on the ECU connector while the pump runs I decided to disconnect the battery and regroup. So why is this the first time the pump energized like it is supposed to (after disconnecting the ECU) and how long would it have run. TIA Steve 
Fuel_Pump_Trouble_shooting_PDF.pdf ( 794.42k )
Number of downloads: 223 |
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| JeffBowlsby |
Feb 14 2016, 02:21 PM
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#2
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914 Wiring Harnesses & Beekeeper Group: Members Posts: 8,982 Joined: 7-January 03 From: San Ramon CA Member No.: 104 Region Association: None
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Unfortunately that test procedure applies to D-Jet cars, not L-jet, which the dual relay is more critical. Hopefully one of our L-jet gurus will jump in on this, Tim, Jim Hoyland, Clay or others. In the meantime, maybe these will help:
Attached File(s)
DualRelayTest.pdf ( 264.12k )
Number of downloads: 59
DualRelayExplained.pdf ( 1.94mb )
Number of downloads: 2240 |
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| r_towle |
Feb 14 2016, 02:22 PM
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#3
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Custom Member Group: Members Posts: 24,705 Joined: 9-January 03 From: Taxachusetts Member No.: 124 Region Association: North East States
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Fuel pump on ljet only runs while cranking or when the flapper on the afm is opened
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