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General => The garage => Topic started by: lukeyyyyyyy21 on 26 May 2011, 18:45

Title: mk4 1.8t agu missfire
Post by: lukeyyyyyyy21 on 26 May 2011, 18:45

Recently found a missfire. Happens around 3k rpm, any speed happens around twice every time i drive it now.

Have plugged it into vas, found no fault codes under engine electronics and fueling. As suspected could be coils... Changed spark plugs to bosch double standard ones.. I've had this missfire since I've put fuel system cleaner in and only run on super unleaded.

Related mods are air filter, and turbo back exhaust. Mileage 104k oil changes every 3k...

Old spark plugs were white so it must be under fueling....

Anyone know what this missfire is because it doesn't just happen under load..and what else to check?

Title: Re: mk4 1.8t agu missfire
Post by: gtibarnesy on 29 May 2011, 20:18

I think there could be a couple fixes for this.  Is the fuel filter new? Could be worth changing to count it out.  Is there a electrical connector on the side of the airbox(not air mass), possible 4 or 5 pin maybe? I have known these to fail and causing running issues

Title: Re: mk4 1.8t agu missfire
Post by: Wayne on 29 May 2011, 20:21

Could be a coil pack playing up

Title: Re: mk4 1.8t agu missfire
Post by: richw911 on 31 May 2011, 22:01

Ignition amp  :wink:

Title: Re: mk4 1.8t agu missfire
Post by: lukeyyyyyyy21 on 02 June 2011, 12:50

Quote from: gtibarnesy on 29 May 2011, 20:18

I think there could be a couple fixes for this.  Is the fuel filter new? Could be worth changing to count it out.  Is there a electrical connector on the side of the airbox(not air mass), possible 4 or 5 pin maybe? I have known these to fail and causing running issues

I changed the fuel filter 8k a go... No electrical connector either...

Title: Re: mk4 1.8t agu missfire
Post by: lukeyyyyyyy21 on 02 June 2011, 12:52

Quote from: Wayne on 29 May 2011, 20:21

Could be a coil pack playing up

if it was the coils wouldn't it come up on the diagnostics with clyinder (?) missfire?

Title: Re: mk4 1.8t agu missfire
Post by: RTechUK on 02 June 2011, 14:21

Quote from: lukeyyyyyyy21 on 02 June 2011, 12:52

Quote from: Wayne on 29 May 2011, 20:21

Could be a coil pack playing up

if it was the coils wouldn't it come up on the diagnostics with clyinder (?) missfire?

The AGU ecus dont reconise missfire detection, You need to do a logging session to test the air fuel ratio this should give you a picture of whats up with you engine.   If it was AUM then it would be eaiser to diagnose as its got wideband lambda an missdet.