I have a 87 t2 Well when I pressurize the system at the turbo with air I can hear air coming from under the uim is this normal or is there a vacuum leak the car acts like it has a vacuum leak it just don't sound right and it runs rough . Also if I pull a vacuum line off and blow air in it I hear air coming from the same place under the uim. I can't see under there so I will have to pull it apart if that not normal to get to the leak so any help will be greatly appreciated. Thanks

 

It could be a number of things if its running rough. I don't know about the vac test but I would assume that it shouldn't leak. The vac lines can crack over time. There are a few under the UIM. I would recommend you buy 10ft of the small hose and replace all vac lines while you have the UIM off. I also used zipties on my vac lines.

Also there is a small coolant hose under the UIM. You might want to replace it as well. IT's a bitch to get the UIM off.

 

most likely the "vac spider" for the oil injectors, though it could be another one as well. If you have the "rats nest" for the emissions system stillin there are probably a ton of leaks. Just remove the UIM and replace all of the hoses like previously mentioned, it's not bad to take it off. It woul;d be worth it to poke around and check the condition of your fuel lines, OMP lines, fuel injector grommets, etc... once you have the UIM off.

 

Saw an FD guy do this... made a pressure tester out of an aluminum plate so he could test with the UIM off. He can even pressure test each runner (there are 4 valves for air)

 

Wow, that is pretty kewl...