Thread: A4 B7 1.8T Lumpy/Rough idling like a tractor after injector change!!

Hi

I have just installed the 386 cc injectors into my 2006 A4 1.8T, the car was running great with the stage one software, but I got greedy and wanted for more, I changed the injectors and re-pressurised the fuel rail, when the car started, it is really rough and lumpy, it goes like vom..vom..vom..vom constantly for 30 seconds and then I switch it off to prevent any damages, which the engine speed very unstable, seems like someone who was revving it on the starting grid

I was thinking it has to be related with the ECU not adapting to the new injector, or one of the injectors is defect, or I haven't connect the harness on properly.

Any idea or contribution will be greatly appreciated, I thank you all for viewing and those who helped out!!

Have you had the fault codes read?

i dont have a vag com so did not log anything, ive searched around and it seems like that will be the case if the ecu is not flashed with the install.

am i right on this?