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Dammit! Fuel trim still rich....

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Old 01-18-2003, 05:49 PM
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Default Dammit! Fuel trim still rich....
Checked for vacuum leaks, changed MAF, FPR, throttle body, coolant temp sensor. 02 sensors seem to be OK.
I'm stumped
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Old 01-18-2003, 05:53 PM
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Default I would do more testing on the 02 sensors..
Thats a tough one.
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Old 01-18-2003, 06:05 PM
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Default Rob... have you done any fuel modifications lately?
Changed a fuel pump or something along that line?
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Old 01-18-2003, 06:09 PM
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Default Even if he did, the pressure should be regulated, no?
I dont think the FPR would allow more than 3.8bar. If anything, it should be his 02 sensors, any one of the four as the B2 sensors have the ablitity to override the B1 sensor signals.. Theyre really the only thing that determine fuel enrichment besides the MAF and tha has already been replaced.. A new FP would only gain efficiency and reliabilty if the flow rates are matched.

But then again, knowing Rob, anything is possible.
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Old 01-18-2003, 06:12 PM
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Default I remember someone replacing a wire on the fuel pump...
if it was Rob...? I dont remember... but if it was Rob... then maybe the replaced wire is sending a different signal allowing a request for more fuel.
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Old 01-18-2003, 06:14 PM
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Default Yeah, that was the sending unit..
It only measures the fuel in the tank to send a signal to the dash.
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Old 01-18-2003, 06:23 PM
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Default If the fuel pump is pumping more fuel in at a higher flow rate
the fuel pressure in the rail is going to change. Then you have to lower the FPR rating or retune the chip.
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Old 01-18-2003, 06:44 PM
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Nope...even tested fuel pressure. It's within spec
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Old 01-18-2003, 06:53 PM
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Rob, how rich is the fuel trim?
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Old 01-18-2003, 07:09 PM
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how did you test the o2s??
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