MK5 Golf GTI

All Things Mk5 => Mk5 General Area => Topic started by: joesgti on February 02, 2010, 09:07:26 am

Title: Fuel Cuts/ miss fire problems.....
Post by: joesgti on February 02, 2010, 09:07:26 am
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!!!!  :surprised: 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,  :sad1: but id be happy to travel to the doctors house so he could do some logs for me  :party:


any help mucho appreciated.
Title: Re: Fuel Cuts/ miss fire problems.....
Post by: gazbutS3 on February 02, 2010, 09:10:22 am
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 :smiley:
Title: Re: Fuel Cuts/ miss fire problems.....
Post by: john_o on February 02, 2010, 09:28:14 am
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

Title: Re: Fuel Cuts/ miss fire problems.....
Post by: joesgti on February 02, 2010, 09:33:02 am
not really sure in 6th as 5k in 6th is VERY FAST.

nothing has been dislodged when installed,
Title: Re: Fuel Cuts/ miss fire problems.....
Post by: john_o on February 02, 2010, 09:46:48 am
ok , np, was just looking to compare low vs high gear.
the car may pull ok through 3rd but stutter in 5th ...
Title: Re: Fuel Cuts/ miss fire problems.....
Post by: joesgti on February 02, 2010, 09:49:03 am
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!
Title: Re: Fuel Cuts/ miss fire problems.....
Post by: Hedge on February 02, 2010, 09:53:12 am
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.

Title: Re: Fuel Cuts/ miss fire problems.....
Post by: joesgti on February 02, 2010, 10:01:35 am
i dont have revo hedge :sad:
Title: Re: Fuel Cuts/ miss fire problems.....
Post by: tony_danza on February 02, 2010, 10:03:11 am
I'm afraid you're going to have to burn your car out then, Joe....
Title: Re: Fuel Cuts/ miss fire problems.....
Post by: joesgti on February 02, 2010, 10:04:37 am
I\'m afraid you\'re going to have to burn your car out then, Joe....

what you mean??
Title: Re: Fuel Cuts/ miss fire problems.....
Post by: tony_danza on February 02, 2010, 10:20:33 am
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?
Title: Re: Fuel Cuts/ miss fire problems.....
Post by: KRL on February 02, 2010, 10:29:38 am
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
Title: Re: Fuel Cuts/ miss fire problems.....
Post by: neg on February 02, 2010, 10:30:47 am
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.
Title: Re: Fuel Cuts/ miss fire problems.....
Post by: joesgti on February 02, 2010, 10:31:59 am
mate, i dont have VCDS, that just confussles me!?!

anybody in the north west with VCDS who has a free day this weekend?? :signLOL:
Title: Re: Fuel Cuts/ miss fire problems.....
Post by: KRL on February 02, 2010, 10:41:10 am
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. 
Title: Re: Fuel Cuts/ miss fire problems.....
Post by: joesgti on February 02, 2010, 10:45:40 am
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. 

id say its around 3k-5k, im really thinking its the pump now. The car drives fast but when really pushing it it stutters. Think im going to put it to bed for a few weeks till my pump comes, then see if the problem is still there, il disconnect the battrey on my dinner and see if its still happens after that.
Title: Re: Fuel Cuts/ miss fire problems.....
Post by: Hedge on February 02, 2010, 10:58:58 am
i dont have revo hedge :sad:

Bummer.  :sad1:

Block one of the intakes.  :wink:
Title: Re: Fuel Cuts/ miss fire problems.....
Post by: joesgti on February 02, 2010, 11:14:24 am
i dont have revo hedge :sad:

Bummer.  :sad1:

Block one of the intakes.  :wink:

il just wait for the pump :wink:
Title: Re: Fuel Cuts/ miss fire problems.....
Post by: KRL on February 02, 2010, 11:29:46 am
Cool, if you do manage to get some logs and need some help interpreting them I will be happy to help  :happy2:
Title: Re: Fuel Cuts/ miss fire problems.....
Post by: vRStu on February 02, 2010, 11:40:03 am
Sounds like you need a pump Joe.   :evilgrin:
Title: Re: Fuel Cuts/ miss fire problems.....
Post by: joesgti on February 02, 2010, 11:42:07 am
Sounds like you need a pump Joe.   :evilgrin:

im on the GB and have paid, 2 weeks wait though
Title: Re: Fuel Cuts/ miss fire problems.....
Post by: john_o on February 02, 2010, 12:01:56 pm
joe things are a bit tight at the moment on my time (new baby due in 6 weeks)
but if I can I'll let you know.

if i got free I was planning to go to the SEAT track day at Oulton on Sat.

sorry I cant commit to more just now
Title: Re: Fuel Cuts/ miss fire problems.....
Post by: joesgti on February 02, 2010, 12:34:28 pm
^^ cheers pal, if you can then PM me and il be down in a shot!  :happy2:
Title: Re: Fuel Cuts/ miss fire problems.....
Post by: joesgti on February 02, 2010, 01:30:42 pm
Unplugged the battery and all seems good now  :confused:

Maintains 12 psi as the lowest in 4th, also no splutters so may have just needed to learn it or something  :confused:

Also emptied my catch can
Title: Re: Fuel Cuts/ miss fire problems.....
Post by: tony_danza on February 02, 2010, 01:52:07 pm
Good stuff  :happy2:
Title: Re: Fuel Cuts/ miss fire problems.....
Post by: neg on February 02, 2010, 03:37:34 pm
joe things are a bit tight at the moment on my time (new baby due in 6 weeks)

Enjoy your time now while you have it  :wink:
Title: Re: Fuel Cuts/ miss fire problems.....
Post by: john_o on February 02, 2010, 05:02:07 pm
 :signLOL: im getting that feeling  :surprised:
Title: Re: Fuel Cuts/ miss fire problems.....
Post by: Top Cat on February 03, 2010, 05:54:32 pm
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?

I am with Danza torch it.  :star:

Title: Re: Fuel Cuts/ miss fire problems.....
Post by: joesgti on February 03, 2010, 06:54:46 pm
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?

I am with Danza torch it.  :star:



thought you might be!!  :fighting2:
Title: Re: Fuel Cuts/ miss fire problems.....
Post by: Phil Mcavity on February 03, 2010, 07:07:04 pm
Who wrote your Remap been done by Joe. Isnt it not a well known one for £200 or something???

Perhaps change to revo joe as your at stage 2+ status now with your mods??

Does sound like fuel stavation by the way it picks up again