Recently, I bought a new rebuild engine then put everything together and then I would crank it then it revs up but it wouldn't idle. Also you would hear a loud hissing noise from lower intake manifold but I replace the gasket 3 times. does anybody know what to put on with the gasket so it would seal

does anybody know what should I do? or does anybody have any suggestions?

1990 stock rebuild turbo

 

free bump....thread moved from 4sale section

 

it should seal up with no problem... are you sure its the lower intake manifold?
your problem sounds like a big vacuum leak, (which definitely could be the lower intake manifold,) but thats weird that it wont seal up. take the LIM off and lay a straightedge on the part that bolts to the engine, also put a straightedge on the block where the manifold bolts to it.
you may just have a fucked up lower intake manifold somehow...is that possible? if that is the source of the huge vacuum leak and you've gone through 3 gaskets, something is wrong.
also, another thing to try:
have your friend spray some starter fluid down there into where your LIM bolts to the block... if it revs up before it dies, then you are probably right about the lower intake manifold not sealing up with the block and creating a vacuum leak... just a suggestion.
good luck friend.