Jerking at 3k untill 4k rpm

[bergezut]

Hai all sifu here....my prob is when hard throttle below 2k rpm and when reach 3k untill 4k my car start jerking and after 4k and above is ok...already setting SAFC and change the plug but the prob still unsolved.Already pening laaa....hopefully all sifu here can give advice...for info my car is myvi with BOT.TQ

 

[clanzkiller]

tis hapen eventhough during engine hot ?

 

[bergezut]

no bro...even nmorning n night still same...my temperature is normal...

 

[clanzkiller]

tat's mean your car starting to jerk when the boost kick in ?
i suspect is your afr setting within the range of rpm

 

[bergezut]

i also think that way...SAFC my foreman already setting..but still same...change plug also same...he suspect my ECU already pening because cannot read the new setting..because after install wastegate running smoothly in 0ne week and after that the problem begin...what should i do all sifu...plzz give me a advice...TQ

 

[SDF]

won't be ECU problem.

1. How was the SAFC tuned ? on road or on a dyno with proper graphs and wide band sensors ?
2. Did you change injectors ?
3. Any fuel regulator used ?

 

[bergezut]

SAFC just tuned on road..currently i using 4E injector and using sard fuel regulator...it is enough for stock 4E injector bro?

 

[clanzkiller]

bro 1 more solution..
try check all your connector/adapter in your engine..
ex.distributer,fuel rail,airflow sensor..well for myvi i not sure got wat connector/adapter...
just plug it out and replug it nicely...

 

[bebolagalas T]

i also think that way...SAFC my foreman already setting..but still same...change plug also same...he suspect my ECU already pening because cannot read the new setting..because after install wastegate running smoothly in 0ne week and after that the problem begin...what should i do all sifu...plzz give me a advice...TQ

bro ur myVI using wat turbo?

 

[bebolagalas T]

SAFC just tuned on road..currently i using 4E injector and using sard fuel regulator...it is enough for stock 4E injector bro?

hv u check ur injector? u r using more than 10 years old injector bro...

 

[SDF]

tuning wit a wide band sensor or juz 'gut' feeling ?

 

[bergezut]

bebolagalas_T-iam using TD04..might be more than 10 year because the injector is for starlet...

sum-dum-fuk - not tuning with wide band just gut feeling like you say...will be tuning wit wide band soon..but must confirm wat problem before tuning wit wideband...barulah worth pay for setting..heheheh

any posiblelity cause that problem????

 

[mag9556]

After 4k no problem already right...
Did u feel that there is some blow sound from the engine when u start to press the pedal harder?
Did u put a airscoop and where is the intercooler located?
Overheat will damage the plug coil...
Check ur plug coil.. might be kong already..

 

[bergezut]

mag9556-the sound when start jerking like poppop sound and after rpm past 4k it ok...i using front mount intercooler...plug coil iam not sure but plug already change.

 

[mag9556]

ur Myvi Auto Turbo?
Have such experience b4..
Try to put air scoop or put a pipe (something like a pipe to get more air from outside, :hmmmm: what it call liao r? forgotten..)
change the plug coil change plug will be no difference as plug coil kong not the plug..
dun forget to take out the plug coil cover as well..
almost forgot.. dun go to Genting or high hill.. ended over heat.. coil bye bye again..
Changed 4 times already..hehehe

Remember.. cool time the coil will be in good condition.. problem comes when coil start to hot!!..

 

[BananaBoyz]

you setting too lean

 

[bergezut]

mag0556-my myvi is manual....i will try ask my pomen checked

Bananaboyz-wat you meen the setting is too lean?need your advice bro tq

 

[drift_devil05]

mag0556-my myvi is manual....i will try ask my pomen checked

Bananaboyz-wat you meen the setting is too lean?need your advice bro tq

Meaning you fuel does not enough to support your current setting....

 

[mag9556]

mag0556-my myvi is manual....i will try ask my pomen checked

Bananaboyz-wat you meen the setting is too lean?need your advice bro tq

Try to borrow the plug coil from you member and put it, u will know it will stable back but not for long, maintain the smooth air passing or going into the engine is the main factor.. somemore.. as taiko banana mention too lean also a factor.. change the coil already and reset the AFR.. better dyno set it.. Good Luck...

 

[bergezut]

any possiblelity beside all the explanation above..just wanna know if the way above tak jalan ...i have alternative way to try..TQ