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Model specific boards => Golf mk4 => Topic started by: bigmarky on 23 February 2012, 10:01

Title: Rough running! - update further help??
Post by: bigmarky on 23 February 2012, 10:01
Suffering power loss and stuttering in 3rd gear as I accelerate around 30-40mph, any ideas???
Title: Re: Rough running!
Post by: BarryMKIV on 23 February 2012, 10:40
Have you had it scanned? First thing I'd go at would be a throttle body clean. Get it scanned if you can.
Title: Re: Rough running!
Post by: navmk4gti on 23 February 2012, 11:05
Are you getting really bad mpg? Could be maf
Title: Re: Rough running!
Post by: bigmarky on 23 February 2012, 12:41
It's dropped to about 28mpg now from 32ish before. does idle funny as I stop at junctions or first start it up but only for about 5-10 seconds drops up and down between 600-900rpm then sorts itself out.
Title: Re: Rough running!
Post by: Rhyso on 23 February 2012, 12:45
It's dropped to about 28mpg now from 32ish before. does idle funny as I stop at junctions or first start it up but only for about 5-10 seconds drops up and down between 600-900rpm then sorts itself out.

Clean out the throttle body as that's free to do if you're handy with tools  :smiley:
Title: Re: Rough running!
Post by: bigmarky on 23 February 2012, 13:22
It's dropped to about 28mpg now from 32ish before. does idle funny as I stop at junctions or first start it up but only for about 5-10 seconds drops up and down between 600-900rpm then sorts itself out.

Clean out the throttle body as that's free to do if you're handy with tools  :smiley:

My guides on here how to do that?? Job for the weekend lol
Title: Re: Rough running!
Post by: Rhyso on 23 February 2012, 13:58
It's dropped to about 28mpg now from 32ish before. does idle funny as I stop at junctions or first start it up but only for about 5-10 seconds drops up and down between 600-900rpm then sorts itself out.

Clean out the throttle body as that's free to do if you're handy with tools  :smiley:

My guides on here how to do that?? Job for the weekend lol

In here somewhere
http://www.golfgtiforum.co.uk/index.php?board=58.0

You can find it  :tongue:
Title: Re: Rough running!
Post by: navmk4gti on 23 February 2012, 14:06
If Was maf will go down to like 15mpg mate so may not be that.. Sounds like you just need throttle body clean as rhyso said.. Easy job :smiley:
Title: Re: Rough running!
Post by: bigmarky on 23 February 2012, 15:04
Will do it tomorrow as I'm in lates, fingers crossed it works. Cheers lads
Title: Re: Rough running!
Post by: bigmarky on 25 February 2012, 14:19
Update - cleaned the throttle body yesterday which was filthy, resulted in sorted idling and massive noticeable difference in throttle response etc BUT under heavy acceleration in 3rd or hitting 80mph it now stutters then misfires !!!! Any ideas anyone???? Oh and the boost pressure has gone fr 18psi to nearly double that!!!!!! Help lol
Title: Re: Rough running! - update further help??
Post by: Wazzzer on 25 February 2012, 14:24
what engine code

you need to check all the PCV pipes in the engine bay for leaks including those under the inlet mani
Title: Re: Rough running! - update further help??
Post by: bigmarky on 25 February 2012, 14:30
It's AGU mate
Title: Re: Rough running! - update further help??
Post by: Wazzzer on 25 February 2012, 14:37
hate to say it but ignition amp?
Title: Re: Rough running! - update further help??
Post by: bigmarky on 25 February 2012, 14:59
It just seems to happen as the boost maxes out though I mean when u floor it the boost is now hitting about 35psi (I'm assuming this is way too high) its then juddering misfiring then keeps going it doesn't do it all the time or under normal acceleration.
Title: Re: Rough running! - update further help??
Post by: richw911 on 25 February 2012, 19:58
Any fault codes? faulty N75....
Title: Re: Rough running! - update further help??
Post by: bigmarky on 25 February 2012, 20:00
Getting it plugged into vag.com tomorrow mate so hoping that will come up with something
Title: Re: Rough running! - update further help??
Post by: tokemk4gti.t on 25 February 2012, 20:10
whats it sound like??? 35psi!!!! mines 18psi and it spools hard!! 35psi man id be scared hearin that spool :-s
Title: Re: Rough running! - update further help??
Post by: bigmarky on 25 February 2012, 21:27
It sounds like a supercharger mate way too loud trust me, it's quick but just waiting to go bang!!!
Title: Re: Rough running! - update further help??
Post by: jonnyturbo on 26 February 2012, 16:32
Well I scanned marks car today and the codes are as follows

16487 - Mass Air Flow (MAF) (G70): Signal too High
16516 - Oxygen (Lambda) Sensor B1 S1: Signal too Low

Would these two cause erratic over boost ? Was no overboost codes . The above was all that was there bar a daft immboliser fault
Title: Re: Rough running! - update further help??
Post by: bigmarky on 27 February 2012, 18:35
Changed MAF today, left battery disconnected to reset, tried and problem still there, boosting to over 35 psi !!!! Any ideas ???
Title: Re: Rough running! - update further help??
Post by: xxChrisxx on 27 February 2012, 19:07
It's sounds like it's not regulating the boost properly. This would cause funny lambda readings.

So whatever funny number sensor/actuator that controls the wastegate.
Title: Re: Rough running! - update further help??
Post by: Wazzzer on 27 February 2012, 19:25
check the pipe that goes to your actuator from the N75, I reckon it's split  :wink:

EDIT just seen Tophers reply too, we're thinking along the same lines lol
Title: Re: Rough running! - update further help??
Post by: bigmarky on 27 February 2012, 21:00
Which pipe is this??
Title: Re: Rough running! - update further help??
Post by: bigmarky on 27 February 2012, 21:01
I've just tightened all pipes hoses etc, taken the dv off, new maf off put them both back on tightened etc. took it for a run and it's now running 22 psi and holding it ????
Title: Re: Rough running! - update further help??
Post by: Wazzzer on 27 February 2012, 22:47
you had a leak on one of the N75 pipes then :wink:
Title: Re: Rough running! - update further help??
Post by: bigmarky on 27 February 2012, 23:15
you had a leak on one of the N75 pipes then :wink:

Can you buy silicone pipe kits to replace all this??? Just to stop any future problems?