i have a 5 year old seat cordoba with the 130 bhp vw tdi.it has recently devoloped a mis-fire under load starting at around 2000rpm,has anyone got any ideas as to what is the cause?any advice gratefully received
thanks andy

http://66.102.9.104/search?q=cache:zL_O9vPYBTYJ:www.vwaudiforum.co.uk/forum/showthread.php%3Ft%3D20942+cordoba+tdi+misfire&hl=en&ct=clnk&c d=2&gl=uk

Just an outside chance

Do the fuel & airfilters need changing !!

Dirty filters are a common cause of low power in diesels.


Ronnie

hi fuel filter was first thing changed and i took the egr valve off and cleaned all the gunge off it,it has only done 47k and has been regularly serviced(diy)

had the same problem on a couple of VAG tdi's all had bubbles in the fuel lines, one was sorted with new copper washers on the banjo bolts, the other one had a chaffed fuel hose from the intake pipe rubbing on the filter feed, the canvas was visable not enough to leak diesel but enough to suck air in

Could be MAF/AFM.

And if it runs better with the AFM disconnected then that is a sure sign of the above.

My first suspect would be the Mass Air Flow sensor (MAF) is contaminated

But before that I would check for any split vacuum hoses.

try post on vwaudiforum.co.uk some good guys with these engine over there.

Misfire is Unlikely to be MAF, but if you disconnect it and the engine runs smoother then it could be. The engine will still be in limp mode so don't expect it to return as normal.

As suggested it could be the vacuum line to the N75 valve on the turbo, or it could be a stuck N75. this moves the vanes in the turbo. depending on how the car is driven its not uncommon for them to soot up.

the egr valve may have stuck open as well.

Worst case it may be a problem with injector or camshaft, the injectors are run from these as its a PD unit and have been known to wear quickly do to poor oil being used.

HTH

Rob

[Edited on 24-2-2008 by onzarob]