A4 1.9 tdi 130 quattro hesitation/misfire

[Ian2012]

My new to me car is misbehaving it has an odd rythmic kind of misfire when you put your down, almost like a judder pretty much happens in all gears, no codes stored car has been remapped according to previous owner. it certainly feels like it.

Any ideas where to start looking?

Thanks

Iain

 

[S4_dan]

If no codes and it's been remapped, I'd be looking at either getting the old map put back on or doing some logs via VCDS.

 

[desertstorm]

If you have VAG-COM you could check some of the measuring blocks on the injectors off the top of my head block 13 and block 20.



Block 13 is the injection quantity deviation and shows if the injectors are balanced. Think block 20 shows the BIP values for the injector. Could be something simple like needing anew fuel filter, the injector harness in the head is quite a common failure and would give you those kind of symptoms. Did you buy it like it is now, hope you got a discount ? .

Karl.

 

[Ian2012]

I test drove it and it seemed fine only on the way home today after picking it up have i really noticed it, it has a huge history with it and only done 124k so i hope its not serious.

if run logs what i am logging and what am i looking for?

Thanks

Iain

 

[pauldazzle]

+1 for Injector harness.

 

[Ian2012]

does sound like it how hard are they to do?

 

[pauldazzle]

Easy job. Rocker cover off, undo 2 bolts, unplug the harness & remove, heat the new harness up a bit to make it flexible so it's easy to reinstall ( you'll see why when you do it). It's best to fit a new rocker cover gasket when reinstalling too. Can't remember the torque settings for the rocker bolt's, but you do them up in a spiral pattern like you would a cylinder head.

 

[Ian2012]

ok thanks for the write up i have done worse (famous last words!!!) parts order on monday then.

cheers

iain

 

[corker1985]

+1 wiring done a few

 

[Ian2012]

How hot does it need to be will a hairdryer do or more like heat gun?

Thanks for all the replies btw

 

[desertstorm]

Either will do you are just looking to get it warm so it's more flexible. Don't leave the part in a garage all night and then try and fit it as it won't be as flexible. Don't get carried away and melt stuff.

 

[pauldazzle]

Left mine sitting on a hot engine for 5 mins.

 

[Ian2012]

cheers all part ordered today plus a rocker gasket hopefully get it done this weekend

 

[Ian2012]

Well today was a lovely cold and crisp day, got the job done and not as bad as i thought it might be, definately have to warm the new one up and after a test drive it now doesn't miss. The re map that's already on it pulls even stronger now, so thanks to all who helped fix another problem.