SCV problem on 90 Hardbody 4 cyl.

[Shack55]

Truck was surging at start but now it hardly turns over when trying to start., won't start now. there was a rattle sound at the back of the engine where the Swirl Control Valve is located also there is a whining sound at the fuel tank although nothing is being done to the truck. Is this the fuel check valve and what funtion does it play. What funtion does the scv play Thanks

[NISTECH]

SCV is for idle quality. the whine noise at the tank is probably your fuel pump. its the only electric motor back there. fuel check valve is not a electric item. it is just what it says "check valve" It keeps liguid fuel out of the evap system components