code 87 help
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code 87 help
book says fuel pump relay circuit fault. any ideas if it's the relay, wiring, pumps, filters, the fuel pumps come on with key on, dont shut off, truck don't start. new pumps, pressure reg. pressure at fuel rail, injectors read good ohms, power at red wires on inj. what am i missing?
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Joined: Dec 2001
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From: UT
KOEO 87 is an electrical fault, so it will have nothing to do with the filters. I'm not real familiar with the differences between a KOEO 87, KOE0 95 or KOEO 96. To be safe, I'd say it could be any part of the fuel pump circuit (including relay, wiring, pumps, inertia switch, fuse, etc.). The fact that the fuel pumps run suggests to me that the fault is in the relay or the part of the relay circuit that connects to the PCM and is responsible for closing the relay. Just to be sure, I'd probably get a wiring diagram and a voltmeter and start probing the fuel pump circuit and the relay control circuit just to see what is going on.
Is there adequate fuel pressure at the rail? If there's fuel pressure at the rail and it isn't starting, I don't know that the fuel pump fault is directly related to the no start. Maybe something unrelated in the PCM wiring is preventing the fuel injectors from opening or the spark plugs aren't firing.
Is there adequate fuel pressure at the rail? If there's fuel pressure at the rail and it isn't starting, I don't know that the fuel pump fault is directly related to the no start. Maybe something unrelated in the PCM wiring is preventing the fuel injectors from opening or the spark plugs aren't firing.
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