Originally Posted by JonathanJ

One thing I have done in the past is to remove a inlet pipe and run it like a N/A and then rev it with your hand over the intercooler outlet and see what pressure you get there , if you have pressure then it is getting that far , it could be a leak and that is what is causing the misfire , sometimes difficult to find , another trick is to start it in a sealed state and spray some brake cleaner towards your suspected leak area , only a quick squirt though , it will get sucked in and will burn like petrol and it will rev , so be careful how much you use .