MK5 Golf GTI

All Things Mk5 => How to Guides / Troubleshooting => Topic started by: Weston on September 22, 2011, 10:37:02 am

Title: Any ideas? Misfire?
Post by: Weston on September 22, 2011, 10:37:02 am
Since my remap I've thought a few times that the car has been running a bit odd. Just now, slight incline, 30mph, 5th gear, 1500rpm & the engine seemed to be behaving strangely. The revs dropped slightly then came back. This happened all the way up the hill. If I put my foot down it runs fine and only does this occasionally. The other times have been less obvious.

Any ideas?
Title: Re: Any ideas? Misfire?
Post by: RedRobin on September 22, 2011, 10:57:58 am
^
Random misfires are often a sign of a coilpack on the way out. Best to check (VAGcom log thingy) before it fails totally and potentially does damage.

Remapped 2.0T FSI engined cars should ideally have their plugs renewed every 10k miles.

Someone else will chip in re what else it could be.
Title: Re: Any ideas? Misfire?
Post by: Weston on September 22, 2011, 11:14:28 am
Cheers  :happy2:

New plugs fitted in March, coil packs on the recall done in July
Title: Re: Any ideas? Misfire?
Post by: RedRobin on September 22, 2011, 12:53:48 pm
^
Then the next question might be which remap?

Someone who can laptop log would doubtless be able to help more than me.
Title: Re: Any ideas? Misfire?
Post by: Weston on September 22, 2011, 12:56:10 pm
R Tech stage 1. I'll see if I can find a member with VCDS close to me (Bristol)
Title: Re: Any ideas? Misfire?
Post by: RedRobin on September 22, 2011, 01:00:03 pm
.
The R-Tech guy is normally very caring and helpful. But VCDS best starting point. Possibly a setting on the map but I'm guessing wildly.
Title: Re: Any ideas? Misfire?
Post by: Weston on September 22, 2011, 01:04:33 pm
I know Nick will be more than happy to have a look for me, and I'm not suggesting it's the remap either as I've only heard positive things about them. I reckon the remap has possibly exposed a weakness somewhere, although my mechanical knowledge is zero.
Title: Re: Any ideas? Misfire?
Post by: fab5freddy on September 22, 2011, 01:29:02 pm
Is it running a bit lumpy at idle? PCV maybe?
Title: Re: Any ideas? Misfire?
Post by: Weston on September 22, 2011, 01:33:17 pm
Is it running a bit lumpy at idle? PCV maybe?

Idle seems fine. New PCV fitted at same time as remap, although that could be the issue. It makes some squeaks, which I think is caused by air in the PCV,
Title: Re: Any ideas? Misfire?
Post by: bacillus on September 22, 2011, 02:47:13 pm
Cheers  :happy2:

New plugs fitted in March, coil packs on the recall done in July

Don't exclude a new faulty coil pack as one member on here found out...
Title: Re: Any ideas? Misfire?
Post by: Weston on September 26, 2011, 11:22:08 am
Well I've scanned the car today and there's no codes at all  :confused:
Title: Re: Any ideas? Misfire?
Post by: Tfsi_Mike on September 26, 2011, 11:58:21 am
Well I've scanned the car today and there's no codes at all  :confused:

Sick of this myself every 3-5k miles now, need a health check to see if there's an underlying problem
Title: Re: Any ideas? Misfire?
Post by: Weston on September 26, 2011, 12:14:03 pm
When yours does it what's it like?
Title: Re: Any ideas? Misfire?
Post by: Tfsi_Mike on September 26, 2011, 12:40:52 pm
When yours does it what's it like?

Started off very slight when accelerating in 4,5 or 6th as if lost power for a fraction. 100 mikes later it was a prominent stutter. Switched to stock map to get to garage for new plugs
Title: Re: Any ideas? Misfire?
Post by: Weston on September 26, 2011, 02:51:23 pm
Hmm maybe it's not the same thing. Mines very intermittent. I wonder if it's the DSG hesitating on a change?
Title: Re: Any ideas? Misfire?
Post by: Tfsi_Mike on September 26, 2011, 04:09:03 pm

Mines certainly the misfire I've suffered lots of times before. Sorry for the rushed explanation was a flying toilet break at services onthe way to the airport.

 Strangely it Isn't noticeable after switching back to st2+ ....  Neeeed to find somewhere suitable to do some logs....
Title: Re: Any ideas? Misfire?
Post by: vRSAlex on September 26, 2011, 04:48:18 pm
What map are you on now?  APR still?  What stage map were you running before you went back to 2+?
Title: Re: Any ideas? Misfire?
Post by: Tfsi_Mike on September 26, 2011, 05:01:22 pm
What map are you on now?  APR still?  What stage map were you running before you went back to 2+?

Still APR till Xmas. Started missing & stuttering on 2+ map, switched to stock and wasn't noticeable, switched back to 2+ for last 30 - 40 miles and wasn't stuttering.  Was alot less weight in the car on the way back (less load on the engine?)
Title: Re: Any ideas? Misfire?
Post by: RedRobin on September 26, 2011, 07:23:37 pm

Hmm maybe it's not the same thing. Mines very intermittent. I wonder if it's the DSG hesitating on a change?
 

....I think a DSG hesitation feels different from a misfire. For a start the DSG hesitation will only happen at the exact moment of your shifting whereas a misfire is usually more throttle related.
Title: Re: Any ideas? Misfire?
Post by: Tfsi_Mike on September 26, 2011, 07:48:21 pm
What map are you on now?  APR still?  What stage map were you running before you went back to 2+?

Still APR till Xmas. Started missing & stuttering on 2+ map, switched to stock and wasn't noticeable, switched back to 2+ for last 30 - 40 miles and wasn't stuttering.  Was alot less weight in the car on the way back (less load on the engine?)

And now started doing it again, cool evening st2+ map. 4th noticeable most. 10 miles of 102ron bp ultimate left.

Title: Re: Any ideas? Misfire?
Post by: Weston on September 26, 2011, 08:12:43 pm

Hmm maybe it's not the same thing. Mines very intermittent. I wonder if it's the DSG hesitating on a change?
 

....I think a DSG hesitation feels different from a misfire. For a start the DSG hesitation will only happen at the exact moment of your shifting whereas a misfire is usually more throttle related.

I need it to happen again so I can decide. Haven't had any issues with the gearbox so far...
Title: Re: Any ideas? Misfire?
Post by: Tfsi_Mike on September 26, 2011, 08:16:47 pm

Sorry for the mini hi jack Weston  :ashamed:
Title: Re: Any ideas? Misfire?
Post by: Weston on September 26, 2011, 08:20:21 pm

Sorry for the mini hi jack Weston  :ashamed:

No worries, it doesn't bother me  :happy2:
Title: Re: Any ideas? Misfire?
Post by: Tfsi_Mike on September 26, 2011, 08:24:12 pm

Goin to buy more damn plugs in the morning  :mad:
Title: Re: Any ideas? Misfire?
Post by: Weston on October 01, 2011, 08:40:43 pm
Well it's done it again. This time with a flashing EML, although it stopped flashing when the juddering stopped. I've now noticed it happens mainly when going uphill. Should be able to scan it tomorrow (not VCDS though)
Title: Re: Any ideas? Misfire?
Post by: Tfsi_Mike on October 01, 2011, 08:46:29 pm

Had mine checked today.  The same happens under load (Uphill or high gears)

Dealer swapped plugs to see if it moved from Cyl  3 but it didnt, then new coilpack and no change.  New Rev PCV next week then looking at injector :sad:
Title: Re: Any ideas? Misfire?
Post by: Weston on October 01, 2011, 08:54:37 pm
Injector would make sense. It doesn't do it driving gently, but if I accelerate quicker than normal driving is does it a little bit
Title: Re: Any ideas? Misfire?
Post by: Saint Steve on October 01, 2011, 08:56:14 pm
Who's your remap Weston out of interest?
Title: Re: Any ideas? Misfire?
Post by: Weston on October 01, 2011, 09:01:01 pm
Who's your remap Weston out of interest?

R-Tech  :happy2:
Title: Re: Any ideas? Misfire?
Post by: Saint Steve on October 01, 2011, 09:01:49 pm
Have you approached them about this fault as yet?
Title: Re: Any ideas? Misfire?
Post by: Tfsi_Mike on October 01, 2011, 09:06:09 pm

John_o had similar symptoms which were caused by faults in APR sofware, discovered and rectified by Awesome Gti...
Title: Re: Any ideas? Misfire?
Post by: Weston on October 01, 2011, 09:08:01 pm
Have you approached them about this fault as yet?

Not at the moment, I think I probably should get in touch
Title: Re: Any ideas? Misfire?
Post by: E30Dom on October 01, 2011, 10:37:41 pm
Can you log individual injectors...?
Title: Re: Any ideas? Misfire?
Post by: Weston on October 02, 2011, 11:51:30 am
Can you log individual injectors...?

Possibly. Had it checked for codes, intermittent misfire cylinder 3 & intermittent random / multiple misfire.

I've borrowed the thing so I should be able to do some live logging & reproduce the misfire
Title: Re: Any ideas? Misfire?
Post by: Tfsi_Mike on October 02, 2011, 11:56:07 am
Can you log individual injectors...?

Possibly. Had it checked for codes, intermittent misfire cylinder 3 & intermittent random / multiple misfire.

I've borrowed the thing so I should be able to do some live logging & reproduce the misfire

Same faults as mine it's like a tfsi virus!
Title: Re: Any ideas? Misfire?
Post by: Weston on October 02, 2011, 12:01:28 pm
Hopefully it's just cylinder 3. Might gave to swap the plug & coil pack with another and see off the fault moves
Title: Re: Any ideas? Misfire?
Post by: Tfsi_Mike on October 02, 2011, 12:05:00 pm
Hopefully it's just cylinder 3. Might gave to swap the plug & coil pack with another and see off the fault moves

That's what I did yesterday and it stayed on cyl 3 :(
Title: Re: Any ideas? Misfire?
Post by: Weston on October 02, 2011, 04:52:56 pm
Just done some logging. Noticed for knock sensor voltage cylinder 1, 2 & 4 were all 0.156 V and cylinder 3 was 0.312 V. Could this be my issue? Are there separate knock sensors?
Title: Re: Any ideas? Misfire?
Post by: vRSAlex on October 02, 2011, 06:44:54 pm
There are only 2 knock sensors.
Title: Re: Any ideas? Misfire?
Post by: Weston on October 02, 2011, 08:22:37 pm
There are only 2 knock sensors.

That's odd then :confused:
Title: Re: Any ideas? Misfire?
Post by: Saint Steve on October 02, 2011, 08:25:05 pm
Sounds like cylinder or valve trouble to me
Title: Re: Any ideas? Misfire?
Post by: Weston on October 02, 2011, 08:36:06 pm
Sounds like cylinder or valve trouble to me

What should I check for / replace Steve?
Title: Re: Any ideas? Misfire?
Post by: Saint Steve on October 02, 2011, 08:48:24 pm
Compression test, to check for 4 uniform compression readings, maybe a rouge spark plug out of the set you bought back in march .

Have you taken the plugs out to see the colour of them?

Unlikely to be an injector if your getting knock sensor imbalance IMO.
Title: Re: Any ideas? Misfire?
Post by: R-tech-Nick on October 03, 2011, 01:29:01 pm
Hello,

I dont thik It will be the remap code as I have not had any issues in the past, but the map and getting the car on full power by fixing the PCV could have highlighted under laying issues, as part of the r-tech remap map we do offer customers a life time of ownership help and advice, in return for a packet of hobnobs each time. :grin:

You more than welcome to pop to us for a foc loging session on the dyno, which should help point you in the right direction.  It could be a coil pack (even the new ones give up easy)  Once its on the dyno I can easy check the fuel and ignition out in around 30 mins, plus we have plugs and coil packs in stock which we can trial and error test with.   Just drop Jim a line at the workshop and he will find a slot which is good for you.

Nick R-Tech
Title: Re: Any ideas? Misfire?
Post by: Weston on October 03, 2011, 02:44:57 pm
Hello,

I dont thik It will be the remap code as I have not had any issues in the past, but the map and getting the car on full power by fixing the PCV could have highlighted under laying issues, as part of the r-tech remap map we do offer customers a life time of ownership help and advice, in return for a packet of hobnobs each time. :grin:

You more than welcome to pop to us for a foc loging session on the dyno, which should help point you in the right direction.  It could be a coil pack (even the new ones give up easy)  Once its on the dyno I can easy check the fuel and ignition out in around 30 mins, plus we have plugs and coil packs in stock which we can trial and error test with.   Just drop Jim a line at the workshop and he will find a slot which is good for you.

Nick R-Tech

Cheers Nick I was gonna give you a call anyway. Just rang up and was told anytime Monday will be fine so I'll come up then, probably be there around 11  :happy2:

Chris
Title: Re: Any ideas? Misfire?
Post by: Weston on October 04, 2011, 02:57:38 am
Just driven home from work & a warning to check the oil has come on. Must admit I've not checked it for a while, could this be related to my problems, or even the cause?