Car a little bit juddery at about 2k revs
 

Hi folks,

recently changed my spark plugs and thought all was ok

I had my fuel injectors changed for bigger ones and the car seems slightly juddery at low revs- about 2k

I had to put 7 pounds of crap fuel in car and car is mapped for v power.

I have put a full tank of vo power in and ran 10 miles- seems to still be a little juddery.
I have new turbo fitted and decat up pipe and waiting for remap.
Car seems fine under boost(not a lot though without remap!)

Any ideas guys? Or do I have to pull out spark plugs again?!Hope not
brk7 gapped to 0.7 ( or so i think)


Cheers folks!!!!

Are you saying it has larger injectors and larger turbo than it was mapped for?

probably due to the injectors etc.. drive it as little as possible and stay off boost etc..

Simon

thanks, yes the car was mapped for a td04 and 380cc injectors.
The car now has td05 16 and 550cc injectors and a decat up pipe.
I also put in 7b ngk spark plugs.
I thought the car was ok untill i put the new injectors in. Injectors have been cleaned and tested and ok.
Although its when you apply a little boost between 0 and 2.5k revs. If you put your foot down no flat spot.
No missfire or pop, seems to be a slight loss of power when applying very gentle boost between 0 and 2.5k revs. Almost like a flat spot if you know what I mean...............slight pull and then lets off for a glitch and then back on.
I dont know whether I should take all spark plugs out tonight and make sure they are all gapped to 0.7mm again or whether its likely to be just needing a map.
I previously had a problem with spark plugs where the car was juddering badly and getting ecu light..............that was due to cracked spark plug.

OH .......it only seems to be 1st gear for sure- possible 2nd:Suspiciou at low acceleration

Thanks sir, Chris

as JGM said, u havent told the ecu u have changed the injectors and turbo basically.

should basicaly re-map after every mod i suppose?

yeah mate, getting remapped on thursday
Im just scared in case the spark plugs are not right, but I suppose it could be the face its not mapped yet (I hope)

I have exact same problem see my other thread

To look at similarities - i changed spark plugs to the PFR7B ones, i also put bad fuel in.

I am just finishing my second full tank of decent stuff at moment, lumpiness still there slightly but still hoping it was just the fuel.

same ill have a look cheers

can you post the link to your link lol
How much much (crap stuff) did you put in?
I put about £9 worth

it IS the fact that it isn't mapped yet. The ECU has no clue that you've increased the fuel flow by some 45% so it's massively overfuelling, especially on moderate load once it's running in open loop.

Best thing is to fit the injectors when you get it mapped, ideally drive to the place you're getting the mapping done and fit them there.

I cant seem to find my thread :S if you click on my username and search previous posts its in there. I dont have permissions to do so as havent joined fully.

I put about £10 in of 95 stuff

cheers lads

https://www.scoobynet.com/general-te...lp-please.html here you go

its the injectors.

:lol:

Guys - I'd listen to Simon - he's an experienced mapper with more experience than most of us on here; suggest you follow his suggestion and either drive it as little as possible!
Whilst for a normal car it might sound like plugs, this is for a new turbo and injectors without a remap - get it to a mapper and take the bits with you!

I cant se why the injectors would cause the problem though....surely the injectors just flow the same amount of fuel through..only larger injectors.

If I had a spark plug not gapped quite right would the ecu put the engine light on?
I dont believe its detting- i had that previously due to cracked spark plugs and it hopped like a frog.
Just like a low rev pull off: pull...pull....pull (hestitant)2k roughly..pull...pull all the way

it's the injectors, pleas don't make this harder than it needs to be.

If you increase the size of the injectors, or rather their flow rate, they will still open the for the same duration. So when you were running (for instance) 12.5:1 AFR on light load you will now be closer to 8.6:1 AFR which is off the scale of most wideband AFR sensors, and will result in a misfire with black smoke.

its the injectors ;) :brickwall:lol1:

right ok ok ok
thank you very much people
I was going to take out spark plugs but ill just leave it then
Thanks for the update folks

might just double check spark plugs tonight

:Whatever_

You can lead a horse to water...

:lol:

lmfao.. nice one

lol...........well if jolly green thinks it aint spark plugs then ill listen to the master. REMAP tomorrow folks!Really excited!

Master indeed!

;)

333bhp 330torque

delighted!!!!!!!

You guys were right....big thanks!!!
Now just gotta keep wheels from spinning in first gear!! lol