Stalling problems after starting.

[Yareck]

Great thread about vapor locking. I applied everything from it and the problem is gone.

http://www.offshoreonly.com/forums/general-q/161147-1997-502-mpi-issues-vapor-lock.html

 

[Nehalennia]

Glad you figured it out.
Rather that point to another article, can you hit the baseline points that solved your issue?

 

[Yareck]

Glad you figured it out.
Rather that point to another article, can you hit the baseline points that solved your issue?

ok so everything is happening in the VST Vapor separating Tank. Mercruiser changed its lids in 1996 and assembled it in a wrong way with the spring that pushes diaphram up is under it(instead above it) and it's constantly closing a valve through which all vapors should be vacuumed once the engine starts.
First I just cleaned all VST because it was clogged and left the spring under that diaphram thinking my problem was solved. It vapor locked anyway. Once that happened I just opened a valve to release vapors and engine started right away.
later I changed position of that spring and it's ok now.
Theres a picture that should make it more clear to understand

http://s1173.photobucket.com/user/r...s/VSToverhaul_zps11689a5d.jpg.html?sort=3&o=0