Hesitation at 3k rpm...poor fuel??

[Cupra R-Will]

My car is remapped so I always fill up with super unleaded, I went to my local shell garage the other day to fill up with v-power as usual but all the pumps were out of order, wasnt really an issue as there is a BP down the road so I just filled up with ultimate. Since then my car hesitates at 3000 rpm in 5th and 6th (pulling from low revs upto 3k then hesitates until about 4k) Could this just be coincidence and a coil pack is on its way out or do cars actually get used to a "specific" fuel - the guy I bought the car off filled up with v-power religiously aswell.

 

[gulzar]

My car is remapped so I always fill up with super unleaded, I went to my local shell garage the other day to fill up with v-power as usual but all the pumps were out of order, wasnt really an issue as there is a BP down the road so I just filled up with ultimate. Since then my car hesitates at 3000 rpm in 5th and 6th (pulling from low revs upto 3k then hesitates until about 4k) Could this just be coincidence and a coil pack is on its way out or do cars actually get used to a "specific" fuel - the guy I bought the car off filled up with v-power religiously aswell.

could well be the fuel quality, but would guess it would be a bit longer if it were to show as hesitation if any. most likely car would feel less urgent.also if map is set for high octane fuel then get some v power or the likes in there soon as it will be running advance timing for the good fuel.

i had some hesitation in mine recently and over the space of a short time got worse till the point the coil pack completely failed.ran like a bag of spanners, could be your culprit. was only slight hesitation at first. hope that helps.;-)

gulzar.

 

[Cupra R-Will]

Yeah thats cool thanks for the info, i thought bp ultiamte was meant to be high octane anyway?! I will wait and see anyway, only got half a tank left now so i will fill her back up with v-power as usual as soon as!!

 

[Cupra R-Will]

Yeah going to get her back onto v-power as soon as possible, if its the same then im guessing it will be coilpack issues or something. Seems like everything is breaking on me, only had the car a month, 4 new tyres, my fan resistors are knackered (massive threads on here about this) my abs light is on and now ive noticed a small crack in my gearbox where the plank that previously had the car must have hit a speedbump!! Bad Bad times!!

 

[DannyC87]

BP Ultimate is 98RON the same as V-Power anyway, so it shouldn't be an octane thing. However the composition of the fuel is probably different, maybe it's just a problem cos it's the first time you've used anything different in a while.

Ultimate is 97, V-power is 99.. Makes a big difference with mine. I am running fairly aggressive timing advance with WMI, but if I use 97Ron instead of 99Ron I get high CF pulling the timing back due to engine knock. (Felt as hesitation within the car, but can be logged on vagcom)

 

[Cupra R-Will]

Thats the answer i was looking for, i was hoping for a reasonable explanation for this, glad something else isnt breaking on me!! hah! Cheers Danny!! Not too sure what CF is...or WMI...but i get the idea

 

[DannyC87]

Thats the answer i was looking for, i was hoping for a reasonable explanation for this, glad something else isnt breaking on me!! hah! Cheers Danny!! Not too sure what CF is...or WMI...but i get the idea

CF is correction factor. Basically, your map has a pre-defined timing advance it tries to achieve; if the octane rating of the fuel is not great enough it will cause pre-detonation (as octane refers to resilience to combustion) which the ECU will "see" through the knock sensors. On sensing this pre-det / knock the ECU will try and pull back the timing using correction factors to the pre-defined value in the mapping.

WMI = water methanol injection (up to 116RON )

edit: In summary, the higher the RON, the less correction factors and so the smoother the drive and greater the power output. Low RON = knock/hesitation.

 

[wayne lcr]

danny nos is stuff

 

[DannyC87]

danny nos is stuff

cheers

 

[Cupra R-Will]

Technical God as far as im concerned!!! hah!