Is it an auto?
Forget the ecu or pump unless they agree to not charge you if it doesn't fix it. Check ALL the vacuum lines ALL the way. You already found one.
If you have a vag com, check the MAF sensor readings and see how requested vs. actual are. If they're way off you found your problem.
Forget the ecu or pump unless they agree to not charge you if it doesn't fix it. Check ALL the vacuum lines ALL the way. You already found one.
If you have a vag com, check the MAF sensor readings and see how requested vs. actual are. If they're way off you found your problem.