After having problems with poor engine idle on my Audi A4 1.8t i’ve replaced the breather regulator valve due to a split diaphragm and cleared all fault codes with a scantool.
The car now runs fine but the engine managment light is still coming on. Fault code “Long term fuel trim”. I’ve checked all vac hoses etc for leaks and it all seems fine, any ideas?
Gra.
Are you 100% sure you dont have an air leak?
there are also two plastic valves that are electronically controlled that may have gone tits up.
Is it a DBW throttle or a cable?
99.5 % sure there’s no air leak, and cable throttle.
How do i check the plastic valves you mention?
Gra.
Can you not delete the long term fuel trims to get them back in spec? thensee if they go out again?
[quote=ade]Can you not delete the long term fuel trims to get them back in spec? thensee if they go out again?
[/quote]
Yes, cleared all fault codes with a scantool and after a short run it comes back.
Does it clear down the actual long term fuel trim value? In my Scooby days you needed to do an ECU reset to do that.
Problem now sorted!
Found a faulty one way valve on a breather pipe under the inlet manifold. Reset codes, car now runs sweet.
Gra.