LS - 1st and 2nd Gen (1990-2000) Discussion topics related to the 1990 - 2000 Lexus LS400

fuel pump cuts out

Old 10-22-08, 07:43 AM
Ridg Ryan
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Default fuel pump cuts out

This 1993 LS400 has an issue with the fuel pump periodically not getting the voltage to run. I have been able to jump the +B to the FP pins in the Data Link 1 box on top of the engine. Usually, this will run the fuel pump but as the weather cools this too has become unreliable. I can run a wire directly from the battery to the DL1 FP pin hole but that runs the fuel pump even when the key is off. I feel there is a short in some part of the harness but have problems finding it. Any ideas to fix this problem?
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Old 10-22-08, 08:38 AM
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sounds like a resistance issue to me
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Old 10-22-08, 10:02 AM
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Is it throwing any codes? In the old days I'd say get a new FP but this may involve other issues.
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Old 10-22-08, 12:16 PM
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It sounds like it's time to change the FP & the FP relay.
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