Hesitation while acceleration, short term and long term fuel

Tiny
FAHAD ANWAR
  • MEMBER
  • 2011 DAIHATSU MOVE
  • 0.6L
  • 3 CYL
  • 2WD
  • AUTOMATIC
  • 132,000 MILES
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.
Do you
have the same problem?
Yes
No
Friday, November 6th, 2020 AT 3:40 AM

7 Replies

Tiny
ASEMASTER6371
  • EXPERT
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
Was this
answer
helpful?
Yes
No
+1
Friday, November 6th, 2020 AT 4:20 AM
Tiny
FAHAD ANWAR
  • MEMBER
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.
Was this
answer
helpful?
Yes
No
Wednesday, November 11th, 2020 AT 11:16 PM
Tiny
ASEMASTER6371
  • EXPERT
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
Was this
answer
helpful?
Yes
No
+1
Thursday, November 12th, 2020 AT 1:20 AM
Tiny
FAHAD ANWAR
  • MEMBER
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?
Was this
answer
helpful?
Yes
No
Thursday, November 12th, 2020 AT 2:24 AM
Tiny
ASEMASTER6371
  • EXPERT
Okay, then it is the fuel pump itself.

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

Roy
Was this
answer
helpful?
Yes
No
+1
Thursday, November 12th, 2020 AT 3:03 AM
Tiny
FAHAD ANWAR
  • MEMBER
Thanks. So it needs to be changed electric fuel pump motor?
Was this
answer
helpful?
Yes
No
Thursday, November 12th, 2020 AT 3:50 AM
Tiny
ASEMASTER6371
  • EXPERT
That is correct.

Roy
Was this
answer
helpful?
Yes
No
Thursday, November 12th, 2020 AT 4:40 AM

Please login or register to post a reply.

Sponsored links