Help! Fuel leaking from intake manifold!!!

[944 Geek]

I have a mystery to solve. I have been cranking the car while working on the electrics (Fuel pump running) and fuel has started pouring out of a cracked hose under the intake manifold in a stream. I am talking a couple of litres.

Glad to find the vacuum leak I have been looking for (idle up hose for AC under the manifold) but how has that much fuel gotten into the manifold plenum? It should have been sucked into the cylinders even if they weren't firing.

Any clues anyone?

[Mike D'Silva]

Is this my neighbour? if not, you have exactly the same thing he just found on his 944 turbo. In his case, it was a return fuel hose I think.. he has ordered parts to fix.

[944 Geek]

Thanks for replying. No I am in Buderim  but it is weird that it filled the manifold with fuel. I don't even know how that is possible. I will have to think this one through.

[Peter M]

Has the diaphragm in fuel pressure regulator failed allowing fuel into the hose to the intake manifold?

[944 Geek]

Thanks for replying Peter. FPR replaced about 6 months ago. Even if it did fail, the way I see it, it should vent fuel into the return line. How does it get into the manifold? The only path to the intake manifold is though the injectors as far as I can tell. I am mystified.

[Peter M]

I'm suggesting that fuel is possibly leaking from one side of the diaphragm to other where it is then sucked into the inlet manifold. Your car may also have a similarly configured fuel line damper that also should be checked.

Suggest you check that the intake manifold port on both the regulator and the damper hold vacuum when you suck on the fitting.

Sorry I can't be more specific as I'm not to familiar with 944's.

The only other possibility is that one of your injectors is leaking.  If the regulator and damper check out, I would then pull the injectors out to check.