Fuel Pressure Up vacuum valve control

[GDII]

Hi,

I'm doing some research for a future project on a Toyota GEN4 3SGTE using a StormX ECU.

The factory ECU uses a VSV to increase fuel pressure for hot starting to overcome vapour lock so I have come to believe. I know others engines do not have this valve but it seems like it was required to make things work a bit better in the OEM sense of things. When the valve is open it references atmospheric pressure to the fuel pressure regulator but when it is closed it references manifold pressure so also helps increase pressure under boost.

Is this valve needed when going to an aftermarket ECU? It's a simple 12V switched valve that I believe only switches during start up when the engine is hot. So I guess you could set it so it opens up to atmosphere when starting (with a starter signal connected to the ECU) and also tell it to operate only when the engine coolant is above a certain temperature.

I'm new to tuning and wiring in LINK ECUs so hopefully it's not a crazy question.

Thanks

Phill

[Adamw]

Several old nissans and mitsubishis in late '80s/early 90's used used a similar system also but it disappeared from most cars mid 90's.  I assume it was something to do with the crude ecu they were using but dont really know.  Possibly needed in some extreme climates but I have never needed it with an aftermarket ECU.  

[GDII]

I've seen it on the early 3SGEs and 3SGTEs but noted it's not on a Blacktop 4AGE. 80s tech and the GEN4 being released in 97 it's still mid 90s tech. I think the GEN5 3SGTE has it too which is a 2002 release.

Ok, sounds like I can remove that valve and just run the vacuum hose direct from the manifold to the FPR. Simplified. Thank you.

[koracing]

Tuning Gen4/Gen5 3sgtes I typically just eliminate this valve and run standard mechanically vacuum referenced fuel pressure direct to manifold.  I've tuned motors with and without it, and have seen no noticeable benefit to keeping this VSV.