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Fuel system 1 status

Help, Advice and DIY Tutorials on Volvo's extremely popular car line -- Volvo's 1990s "bread and butter" cars -- powered by the ubiquitous and durable Volvo inline 5-cylinder engine.

1992 - 1997 850, 850 R, 850 T5-R, 850 T5, 850 GLT
1997 - 2000 S70, S70 AWD
1997 - 2000 V70, V70 AWD
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Resistolcowboy
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Resistolcowboy

Fuel system 1 status

Post by Resistolcowboy » Thu Apr 25, 2019 12:46 am

Closed loop, using at least one oxygen sensor but theres a fault in the feedback system. this fault happens only at 1500 RPM and lower, then will go into closed loop, using oxygen sensor feedback to determine fuel mix above 1500 RPM. I have also noticed at intermitent times that it will stay in the fault in the feedback system status till engine reaches 198* degrees and above. [ History ] New upstream O2 sensor, Will this status effect fuel econemy or is it normal for a 1997 volvo 850 O2 sensor to operate like this?



Ozark Lee
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Ozark Lee

Re: Fuel system 1 status

Post by Ozark Lee » Thu Apr 25, 2019 7:59 pm

Mine always go closed loop fairly quickly, even on a cold day a city block or 2 will do it.

Anytime you are open loop the fuel mileage will suffer.

What kind of sensor did you use?

...Lee


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Resistolcowboy
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Re: Fuel system 1 status

Post by Resistolcowboy » Sat Apr 27, 2019 10:56 am

I installed a Bosch O2 sensor from IPD. A automotive technician from the college I work at says the O2 sensor is not sending feedback to ECM, but the fault in the feedback system happens at 1500 rpm and lower only. I'm gonna inspect the wires at the connecting harness before the Sensor. Other than the fault my 850 gets 19.5 to 20 MPG City and 26 to 29 MPG Highway.



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abscate
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abscate

Re: Fuel system 1 status

Post by abscate » Wed May 01, 2019 4:06 am

This could be a case of the diagnostic tool not reporting correctly.


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