93 cutlass 3.1 multi port

I have a 3.1 multi port that spews fuel out the air flapper valve as soon as the engine starts cranking over. The under side of the car was hosed down and the car then driven in sub zero temperture shortly before this problem appeared.Could a sensor be damaged or iced up? Any ideas.

I have a 3.1 multi port that spews fuel out the air flapper valve as soon as the engine starts cranking over.

I would like to know where the air flapper valve you are talking about.

For the 3.1 MFI, the fuel goes to the fuel rails. The fuel rails has a fuel regulator which is connected to a vacuum hose. If the inside diaphragm of the fuel regulator is ruptured/crack, then the vacuum hose will be pulling fuel out of the fuel regulator and into intake (rich condition). To fix a ruptured/crack diaphragm of the fuel regulator is to replace the fuel regulator itself.

I would like to know where the air flapper valve you are talking about.

For the 3.1 MFI, the fuel goes to the fuel rails. The fuel rails has a fuel regulator which is connected to a vacuum hose. If the inside diaphragm of the fuel regulator is ruptured/crack, then the vacuum hose will be pulling fuel out of the fuel regulator and into intake (rich condition). To fix a ruptured/crack diaphragm of the fuel regulator is to replace the fuel regulator itself.

Thanks Slade901; You were exactly right. I removed the vacuum hose
on the intake and turned on the fuel pump, gas shot out two feet! Once I replace the regulator $125cnd. I'll change the oil and probably remove spark plugs to expel any raw fuel.I had asked a number of mechanics and they were all stumped. Thanks again.