When i say blown i am not sure if its damaged by a high voltage or a back fire of hot gases or presure but it is being damaged somehow.I am testing them using live data which shows a constant low air flow reading under all engine revs and doesnt change no matter what unless it is disconected and then it reads zero.I too have had many injector and pump problems on these vans as well as loom problems but it runs fine when the new air flow is fitted for a short time .