Hesitation/stuttering when accelerating

[cy88]

Hi all,

I am not sure if this has been discussed before (or if anyone having this issue), but search didn't reveal anything.

There are some very noticable stuttering when if I accelerate when the car is at low rpm while in 2nd/3rd gear. For instance, when the car is going at 30 - 40km/h in 3rd @ ~2000rpm and if I decide to gas a little harder, you can feel the stuttering. It will go away when it hits 3k rpm or so, and will not appear in 4th - 6th gear. Having that said, I also tried to accelerate under the similar condition (2k rpm) in my higher gear, and I did feel the stutters but not as servere.

I swapped car with my friend's MSP6 for a night since he needed my hatch to move something (convinience of a hatch eh? ;)), and did notice the stutter but very very minor unless you hunt for it. He does have a BOV on it, and that's about all the internal mods he has. My friend told me that is hesitation from my tubo.

Should I be concern? Would that be anything to do with BPV leaking? Software reflash?

Thanks for all your advices in advance,
Chris

[RX9]

Hi all,

......going at 30 - 40km/h in 3rd @ ~2000rpm ....Chris

thats why. theres not enough torq/boots at that rpm.

[kaval]

Misfiring?

[cy88]

thats why. theres not enough torq/boots at that rpm.

I did think about that too, but is this the normal feedback that it'll give when it's under-boost/tq?


Misfiring?

How do i tell?

Sorry it's my first turbo/manual car, so I am quite newbish.

I posted this on mazda3forums as well, someone suggested it might be something to do with the furl pump service bulletin 01-022/08:


DESCRIPTION
Due to low fuel pressure at the high-pressure fuel pump, some vehicles may experience the following:
• Rough idle, stall, and/or hesitation under cold conditions.
• Intermittent lack of power during acceleration when the engine gets hot.
• MIL turns on with DTC P2177/P2187 (fuel system too lean at off idle).
This is caused by a delayed fuel pressure build-up from the high pressure fuel pump. There are two main reasons
for this:
1. The drive current from the PCM is not enough for some fuel pumps.
2. Some fuel pumps have slower response.
To fix the problem, the PCM software and the specification of the high-pressure fuel pump have been changed.
Customers having this concern should have their vehicle repaired using the following repair procedure.

Any insight?

Thanks again!

[WeatherB]

What do you mean by hesitation?

Don't expect the car to take off until you start building boost around 3000rpm.

[RX9]

I did think about that too, but is this the normal feedback that it'll give when it's under-boost/tq?

you need to rev higher in order to unleash the power of the snail. try down shift one gear next time.:)

[Garu]

Knock retard?

[Unoriginalusername]

is your car completly stock? have you taken it in for all recalls? I got that problem after the most recent recall and had to go back for a another PCM update. Its been ok in the warmer weather but i think the car will need the fuel pump repalcement to survive in the winter.

[cy88]

you need to rev higher in order to unleash the power of the snail. try down shift one gear next time.:)

I agree, but is this a normal "feedback" i should be getting if i am under reving?


is your car completly stock? have you taken it in for all recalls? I got that problem after the most recent recall and had to go back for a another PCM update. Its been ok in the warmer weather but i think the car will need the fuel pump repalcement to survive in the winter.


Yup, completely stock. I took it in for an oil change, and the guy pulled up my VIN number as currently no outstanding recalls and printed me a page as a confirmation. Is there another way to check for recalls?

[Unoriginalusername]

my issue is back in the colder air today

[alhope34]

I only get hesitation/studdering 3-5000rpm when the ECU is relearning fuel/boost trims. For my case I think it's just the ECU getting too wastegate happy trying to find the target boost numbers.

Goes away after 100kms or so after ECU reset, and I can feel the car getting stronger on every pull.

[Fobio]

my issue is back in the colder air today

did you end up doing the fuel pump tsb?

[Unoriginalusername]

did you end up doing the fuel pump tsb?

no not yet, i just had the flash which helped in the warmer weather and then it got warm fast and hasn't been cool since so it was fine... until this week.

makes me think the pump is needed. Ironically i just told the service manager when asked a week ago how the car has been since the flash and i replied it seemed fine. guess i spoke too soon lol

[Garu]

You know Denso ITV22 plugs did make difference after putting them in my car.