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VW Polo 1.4 16v 2000 - Very bad misfire at 2000 rpm on very light throttle ok when under load #

Posted by Peter Cooper on February 19, 2009, 2:01 pm

Year of Manufacture *: 2000
Engine Code or Type *: AUA

V.W. Polo 1.4 16v 2000 year very bad misfire at 2000 rpm on very light throttle ok when under load.

This car has a bad misfire when on light throttle and cruising at 2000 revs. It dosent do it straight away but if you are on a long straight road it starts missing as if the mixture is weak.

I have checked plugs and leads.

I have checked for air leaks and none found.

I have cleaned out throttle body and reset adaptions.

I have checked for fault codes using VCDS and none found.

Live data looks ok to me.

The multi fuel trim was at 12.
I reset this and still the same.

Can anyone help on this on.

Best wishes

Peter Cooper

Re: V.W. Polo 1.4 16v 2000 year very bad misfire at 2000 rpm on very light throttle ok when under load

Posted by Sean Mc Gettigan <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5291' width='330' height='300' border=0 style='border:none;'> on February 19, 2009, 4:05 pm, in reply to "V.W. Polo 1.4 16v 2000 year very bad misfire at 2000 rpm on very light throttle ok when under load"
Sean McGettigan

Hi Peter, has this got the g/box that was fitted to the maestro's?
If so they have issue's with diff wear which will give your symtoms.
Also these engine's are crap, bad for sticky valves etc.
Hth Sean

Re: V.W. Polo 1.4 16v 2000 year very bad misfire at 2000 rpm on very light throttle ok when under load

Posted by Dave Hill <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT2783' width='330' height='300' border=0 style='border:none;'> on February 21, 2009, 7:07 pm, in reply to "Re: V.W. Polo 1.4 16v 2000 year very bad misfire at 2000 rpm on very light throttle ok when under load"

Good point Sean.

Last year I had one of these that I spent an hour chasing the notion that I had a fuelling fault, as that is exactly what it felt like on the road. With no DTC's (Diagnostic Trouble Codes) present & Lambda confirming adequate fuelling, I was almost stumped.

Fortunately the fault developed quite quickly & the diff starter to "screech" as the crown wheel started to eat away at the casing. Apparently the rivets that secure the crown wheel onto the planet gear carrier are renound for coming loose.

Funnily enough, when I rang the customer to bring her up to speed, she was almost as well informed as me, as she had "Googled" the fault that I had previously explained.

Bloody tinternet is a double edged sword isn’t it!

Cheers

Dave

Re: V.W. Polo 1.4 16v 2000 year very bad misfire at 2000 rpm on very light throttle ok when under load

Posted by Sean Mc Gettigan <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5291' width='330' height='300' border=0 style='border:none;'> on February 28, 2009, 8:01 am, in reply to "Re: V.W. Polo 1.4 16v 2000 year very bad misfire at 2000 rpm on very light throttle ok when under load"
Sean McGettigan

Any update Peter?

Re: V.W. Polo 1.4 16v 2000 year very bad misfire at 2000 rpm on very light throttle ok when under load

Posted by Peter Cooper <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5508' width='330' height='300' border=0 style='border:none;'> on February 28, 2009, 7:14 pm, in reply to "Re: V.W. Polo 1.4 16v 2000 year very bad misfire at 2000 rpm on very light throttle ok when under load"
Peter Cooper

Thanks for all your replies.

It didnt have the maestro type gearbox.

Im prety sure it wasnt a gear box fault but not 100%.

I started to think it could be a slightly sticking open EGR valve or 02 sensor faulty and weakening it off.

The customer decided she didnt want to spend money on diagnosis and said she would trade it in and get something newer.

What a pain I sat up all night reading the workshop manual and searching the internet etc.

Thanks again

Peter Cooper

Peter Cooper

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