a4 1.8 adr has no power and also backfires at 2000rpm if i step on pedal.
What can cause this?

 

Need more info. What does "adr" stand for? Any CEL or trouble codes? Any modifications to the car?

 

It is most likely misfiring, not backfiring. Since it happens under load I suspect the coil packs or ICM have gone bad.

You should scan for codes so we can diagnose the problem. You can buy a VAGCOM cable on ebay for $5, or take it to a parts store to be scanned (if your state allows that, can't do it in CA.)

 

I did vagcom scan and no trouble codes, also did datalogging and all was norrmal exept intake air temp sensor was 19,5 but i think early ones didnot have it.
3,5 g/s airflow at idle at load also logical,coolant temp sensor fine, lambda seeemd fine etc.

ADR stand for engine code.

I think 1 spark plug wire is not best but how do i check coil pack other than resistances?
and ignition control how to check thatone? do i need to do oscilloscope tests primary coil wires?

 

Ahh that's where I got lost, ADR isn't a US-spec engine code. Where are you located? That's a non-turbo petrol engine, right?

 

yes , i am in europe , estonia

 

Do you see a flashing check engine light when the car misfires or backfires? Seems odd there wouldn't be any codes or anything, that sounds like more than enough to upset the ECU

 

gives this sometimes

1 Fault Found:

00561 - Mixture Adaptation
15-00 - Adaptation Limit (Add) Not Reached


and thats it for now.

 

if someone can explain please.

 

so is it lambda is getting slow on updtes?