Misfire when warm - VW Bora 1.6

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Tue 5 Apr 2005 13:54
Misfire when warm - VW Bora 1.6 - MagicBoyUK
I've got a 99 Bora 1.6 8v. It started misfiring and running poorly
at the weekend only when warmed up showing 80C+ on the temp gauge. The car runs OK on low throttle openings but when accelerating at more than granny pace or a steady 50mph+ it's misfiring.

The car is in with a local dealer today - just had a phone call with the findings. They're claiming it's showing faults with both lambda sensors, the engine speed sensor and the MAF, and they all need replacing at lets just say over £750.

I'm not convinced that there's multiple components causing the problem, but the dealer are unwilling to start changing individual bits to isolate it further saying it keeps returning the same faults after a reset.

Can anyone offer some technical guidance as to where to start?
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Tue 5 Apr 2005 14:31
Misfire when warm - VW Bora 1.6 - borasport20
I don't know where you are, with a car of this age,it would be worth finding an independent who specialises in VAG cars.(and having had 18 months of problems on a 2.0 Sport that the dealer never resolved !)

I'd guess if you have the skill and room to work replacing the lambda sensors shouldn't be to difficult. does that model have an ignition unit or coil packs, and have they been ruled out of the equation


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Tue 5 Apr 2005 14:45
Misfire when warm - VW Bora 1.6 - MagicBoyUK
It went in for something else - I ripped the undertray on a broken speed bump. Anyway ... there's no way I'm volunteering to spending all that so I'm working on the bad in = bad out principle. I've told them to replace the MAF and we'll see what happens after that. I'm hoping the others are logging faults as a consequence of the MAF fault. Otherwise it's going elsewhere for the lambda sensors - VW want over £350 for the pair.

Luckily no coil packs on the 1.6 8v - got a proper old fashioned coil.
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Tue 5 Apr 2005 18:15
Misfire when warm - VW Bora 1.6 - borasport20
if you get round to replacing the HT leads, I'd recommend Magnecor - you get very good service

lamda sensors £86-£97 from eurocarparts
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Tue 5 Apr 2005 19:00
Misfire when warm - VW Bora 1.6 - Stuartli
Could be worth looking at GSF's prices as well:

www.gsfcarparts.com/

Whenever my 1999 Bora (16v 1.6) has an MOT, they always have a job testing the emissions because of the difficulty holding a steady throttle setting; something to do with a fly by wire throttle linkage IIRC.
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What\'s for you won\'t pass you by
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Tue 5 Apr 2005 20:43
Misfire when warm - VW Bora 1.6 - Aprilia
Its highly unlikely that all of those parts have failed. Just sloppy diagnosis by someone who doesn't know what they are doing.

The lamda sensor can be checked using a £5 multimeter. Watch it switching at idle (0-1v approx). If switching properly then they don't need swapping out.
A lot of MAF sensors are also swapped on a 'poke and hope' basis. This is plain stupid. Take it somewhere where the technicians know what they are doing.
My first port of call would be the ignition system - possibly coil.
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