Hesitation while acceleration, short term and long term fuel

2011 DAIHATSU MOVE
132,000 MILES • 0.6L • 3 CYL • 2WD • AUTOMATIC
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FAHAD ANWAR
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I have a hesitation while acceleration. can you please check the o2 and fuel term reading in a video? is there any abnormality? There video is while I am driving 0to100km/h.
In morning it take just a little more cranking to start in this car have eco idle function.
Nov 6, 2020 at 3:40 AM
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ASEMASTER6371
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Good morning,

The readings look good. The long term is the key. It should be close to 0. It may roam around 0 plus or minus about 3%.

I would check the fuel pressure. The pump may be draining down overnight losing its prime.

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

https://www.2carpros.com/articles/how-to-replace-an-electric-fuel-pump

Roy
Nov 6, 2020 at 4:20 AM
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FAHAD ANWAR
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How to check this type of fuel pressure regulator? it does not have any vacuum connection . And yes fuel pump does not hold pressure . Can a one way valve can do some? And at idle ltft stays -4.7 and sometimes -6.0. if fuel pressure isn't good then my ltft should be positive I guess.
Nov 11, 2020 at 11:16 PM
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ASEMASTER6371
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Okay, if the fuel pressure drops off, it could be either one of the injectors leaking down bleeding off the fuel pressure or it could be the check valve in the pump itself.

The injector rail off as in the picture you see, pressure up the pump with the key on and see if any of the injectors are leaking fuel.

Roy

Nov 12, 2020 at 1:20 AM
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FAHAD ANWAR
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I already checked the injector by disconnecting fuel rail and key on no fuel drips while in switch on..
And what about long-term fuel trim -4.7?
Nov 12, 2020 at 2:24 AM
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ASEMASTER6371
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Okay, then it is the fuel pump itself.

The long term is good. It should be -5 to +5.

Roy
Nov 12, 2020 at 3:03 AM
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FAHAD ANWAR
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Thanks. so it needs to be changed electric fuel pump motor?
Nov 12, 2020 at 3:50 AM
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ASEMASTER6371
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That is correct.

Roy
Nov 12, 2020 at 4:40 AM