Fuel Cuts/ miss fire problems.....

[joesgti]

OK please help!

Car is a KO3 gti, s3 cooler, tbe, forge dv, twintake celtic remap.

Since putting the twintake on, my car almost goes into limp mode in 4th gear 5th gear at high rpm. boost falls from 15 psi down to about 5psi, but then boosts back up to 10 after a few more rpm.

Also im not sure but the twintake seems to give me a higher peak boost of 26psi!!!!   as apposed to 22 psi before, its like the car is over boosting, but it the falls to 10, splutters about abit, finds its ground and then were off again. VERY STRANGE,

After reading a few other threds they all seem to be on KO4 cars having problems,

Im thinking its either in desperate need of a hpfp as its getting alot more air now and cant cope with the small amount of fuel, OR my coilpack is going, if anybody can shed some light that would be GRREEEEEEEAT!
Oh and i dong have VCDS so cant do any logs,   but id be happy to travel to the doctors house so he could do some logs for me  


any help mucho appreciated.

[gazbutS3]

If its only just appeared since putting the intake on Joe, I'm going for fuel cuts because more air is supplied but the original fuel pump can't deliver the goods, but its only a guess without logging it

[john_o]

4 psi jump is a lot!
first check would be something hasnt been dislodged on the install..
even refit original to confirm it goes back to old ways.

can you reset with that map to get the car to re-adapt again with the intake fitted.

is the car different in 3rd gear pulls compared to 5th/6th gr pulls ?
if it were fuel cut I would expect lower rpm problems Gaz?
still prob fuel issues though...

when I go from std to mapped I always get about 2 'high psi' pulls for the software to adapt, then later on it always steadies

[joesgti]

not really sure in 6th as 5k in 6th is VERY FAST.

nothing has been dislodged when installed,

[john_o]

ok , np, was just looking to compare low vs high gear.
the car may pull ok through 3rd but stutter in 5th ...

[joesgti]

it can be fine in 3rd, but then sometimes it splutters abit, drops to 15psi and then let off the accelarator, boot it again and it wont go over 15psi?? let off and boot it again then it will go upto 25 psi!

[Hedge]

Do you know what settings you are running? This sounds like classic fuel cut symptoms.

I would suggest turning them down to start with to something like 6-5-9 or even 6-3-9 and going from there.

[joesgti]

i dont have revo hedge

[tony_danza]

I'm afraid you're going to have to burn your car out then, Joe....

[joesgti]

I\'m afraid you\'re going to have to burn your car out then, Joe....

what you mean??

[tony_danza]

I've taken to only offering extreme advice to fix problems - just burn it out. It won't do it again.

Tug the battery for 15 mins and re-adapt the car, see if it still happens?

[KRL]

If you have access to VCDS log block 230 and it will be very obvious if your problem lies with the OEM HPFP.  I agree that its the most likely culprit and it would be best to log it to make sure.

- The data should be logged using Advanced Measuring Blocks in the Engine Controller
- The “Turbo” mode should be activated to ensure a decent data sampling rate

VAG-COM BLOCKS TO LOG:

ROUND 1 LOGGING: USE FOR BOOST AND FUELING DIAGNOSIS
Item #   Vag-Com Block #   Description
1   001-1   Engine Speed
2   054-3   Accelerator Pedal Position
3   054-4   Throttle Plate Angle
4   101-3   Injection Timing (Median)
5   114-4   N75 Duty Cycle
6   115-3   Boost Pressure (Specified)
7   115-4   Boost Pressure (Actual)
8   230-1   Rail Pressure - Specified
9   230-2   Rail Pressure - Actual
10   103-1   Current Fuel Pressure
11   031-1   Lambda, Current Value
12   014-3   Misfire Sum

[neg]

I was going to suggest dropping the boost - maybe your now boosting too high, needing more fuel - or just the hight boost is causing limp mode.

[joesgti]

mate, i dont have VCDS, that just confussles me!?!

anybody in the north west with VCDS who has a free day this weekend??

[KRL]

If you are getting proper fuel cuts your car will be throwing some fault codes for fuel cuts and misfires.  The likely reason for it is that the Twintake is flowing a lot more air than your previous intake.  Due to the extra air air coming in while the car is boosting more fuel is required to maintain the specified AFR.  However the OEM pump could be struggling to provide that extra fuel.

At what point in the rev range are you getting the problems?  I would expect the fuel cuts to be happening from 2000-4000rpm as the cam which is driving the HPFP will not be spinning so fast making it even more difficult for the pump to supply the requested fuel.