Audi B5 1.8T Wont start

[Daniel Iversen]

So, long story short.
I was out driving on saturday and My car was sitting and idling for about 5 minutes while i was cleaning of small Stuff on the car.

Suddenly the car just turned of, like If i was to turn of the ignition.
The Car wouldnt start. But it would run on the starter only.

I took out fault codes with VCDS. The fault code it made was on the main relay.


Thanks

 

[aragorn]

main relay is in the ECU box under the bonnet. usually labelled 30

 

[Daniel Iversen]

main relay is in the ECU box under the bonnet. usually labelled 30

Thanks that fixed it.

Now thats fixed. The car ran fine for about 5 minutes until the engine was all warm and ready to be beaten.
And of course, with a problem fixed, another appears.

Car now misfires at idle and when driving.

I myself is thinking that its a coil pack thats now making problems for me.

VCDS shows no fault codes on the coil packs, but a front 02 sensor.

 

[aragorn]

Missfiring causes lots of oxygen in the exhaust which can throw lambda faults.

Bad Lambda can cause fuelling issues which cause missfires.

 

[aragorn]

Unplug lambda and reset the fuel trims and see if the missfires go away.

 

[Daniel Iversen]

Unplug lambda and reset the fuel trims and see if the missfires go away.

Unplug the wire, so that it runs without lambda then?

If it stops misfiring, it it then just the lambda sensor that needs replacing?

 

[aragorn]

yep. but you'll need to reset the trims after unplugging it, with vcds or similar.

 

[Daniel Iversen]

yep. but you'll need to reset the trims after unplugging it, with vcds or similar.

English is not my main language. What do you mean by resetting the trims? deleting all faults or how?

 

[aragorn]

yeh reset fault codes will zero out the fuel trims.

 

[Daniel Iversen]

yeh reset fault codes will zero out the fuel trims.

Thanks for your help. I Will report back once i try this in the coming days