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-   -   removing vst tank on 96 454 mpi (https://www.offshoreonly.com/forums/general-q/203634-removing-vst-tank-96-454-mpi.html)

picca00 02-21-2009 04:28 PM

removing vst tank on 96 454 mpi
 
hey guys im a new member here and new to bbc. i am repowering my 1978 glastron with a 1996 fresh water cooled454 mpi motor. the motor hadabout 100 hrs and was super clean. i just finished rebuilding it, keeping it stock with the exception of the intake, it came off a 502 mag. the mpi motors use the same intake so its basically just the sticker on top thats different. the boat is also getting a full remodel with custom transom, stringers, and floor(see thread in g.d.) i use this boat for mostly wakeboarding but i also like to goes as fast as i can, when possible.
any way i have been reading alot about vapor lock on these motors so i looked into my vst tank to clean the screen and all the parts were gone! i know they are pretty pricey so i was wondering has anbody removed the vst tank all together? its also hitting part of the cover so taking it off would help. whats the process of removing it and running all the lines. i also have a fuel cooler. which maybe gets removed too? will removing it hurt me in anyway? thanks jay

http://i231.photobucket.com/albums/e...90211-1430.jpg

Raylar 02-22-2009 02:47 PM

If you are going to use an external fuel pump-pumps assembly and a fuel cooler on the return side, you won't need the VST assembly at all.

Best Regards,
Ray @ Raylar

picca00 02-22-2009 06:55 PM

can you explain a little bit more... thanks
jay

conquest30' 02-22-2009 10:16 PM

ya can u draw a diagram, im a visual learner lol. im doing the same thing but putting a aeromotive pump and supercharger with intercooler. im running one line into a sea strainer and two out, where would be a good place to put the fuel cooler? sorry picca dont mean to jack your thread

Raylar 02-23-2009 12:42 PM

EFI fuel pump plumbing 101
 
I'll try and make it as simple as I can here based on what you guys are trying to do. A line hopefully 3/8" or 1/2" or AN equivalent size comes from your fuel tank to your fuel water seperator filter, then the line goes to your new fuel pump. Out of the fuel pump route the line to an adjustable efi pressure type fuel pressure regulator (35-65psi rated).
The same size line then exits the fuel pressure regulator flow thru port and goes up to the inlet fitting on your fuel injector fuel rail.
Another 5/16" or 3/8" line runs from the bypass port on the fuel pressure regulator to a fuel cooler, fed with cool raw water. This line then runs out of the fuel cooler back to another inlet port on your fuel water seperator fuel filter. This allows the fuel that a lot of the time is being sent back unused from the regulator to go to the fuel cooler where it is cooled before being returned to the fuel pump for . repumping and repressureizing to the engine.
this type of system will feed the proper amounts and pressures of fuel to the injectors and keep the circulating fuel cool to prevent fuel boil and possible vapor lock.
Hope this helps!

Best Regards,
Ray @ Raylar

picca00 02-23-2009 07:57 PM

hey ray thanks, i got that for the most part, but my fuel rail has 2 lines going into it and the regulator is mounted to the front of the rail. is one going in fuel and the other one vapor out to vst? do i need to move my fuel pressure regulator?
jay

picca00 03-03-2009 02:30 PM

help?!

Pismo10 03-04-2009 10:26 AM

http://www.offshoreonly.com/forums/g...-new-post.html

Good stuff on removing the VST.

picca00 04-18-2009 09:53 PM

hey ray, i think i have it figured out. i need to use the mechanical fuel pump, to draw and pressure the new electric efi pump i got? basically my plan is to put the electric pump right where vst tank was, because the new pump will plug into old connector that went to vst. i have a fuel cooler that has 4 lines, i think it cools the fuel before and after. am i on the right track? and what do you do with the vent line that went from vst to air pelum?
thanks jay


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