Fuel in plenum

[Daneums]

Started on replacing valve cover gaskets and timing belt replacement today. When I pulled off the lower plenum, it was seemed very gunked up and had gas almost dripping off of it. The gasket and intake surface were wet. The inside of the intake appears very dirty to me as well. It has also been parked and not ran for nearly a week. I'm thinking leaky injectors and or fuel pressure regulator. I think it could also explain part of my poor MPG (10-12 city). Thoughts?

 

[Daneums]

Pictures
Lower plenum where upper connects:

Lower plenum where it connects to intake manifold:


Intake manifold:

 

[Hopeless Diamond]

Well the injectors are after the plenum, so probably not fuel. Probably oil/carbon build up from cylinder ring blow-by through the PCV.

 

[Daneums]

pcv valve is good. Gunk may be from previous one that i replaced. My main concern is fuel in the plenum. Doesn't seem normal to me.

 

[spartacus]

thats oil and carbon buildup. faulty pcv valve. look at the fuel line connections. for leaks.

 

[octanejunkie]

I've seen worse pics of the plenum runners, FWIW mine were dark honey-colored when I pulled them so a bad PCV at some point in the vehicle's history makes sense.

Just on a hunch, what does your throttle body look like?

 

[AntleredRuin]

If you're sure it's fuel (hard to mistake that), then you probably have a bad fuel pressure regulator.

What happened with mine was the little valve in it failed and it drained fuel into the air baffle from the hose running under (between upper and lower) the plenum. My air baffle was full up, to the point of being sloshy. The plenum is right between the baffle and the throttle body, so I would not be surprised if fuel wound up in there.

The FPR is at the very back of the fuel rail, driver's side, unfortunately.

 

[spartacus]

check the fuel return hoses going to the plenum. it could also be leaking from elsewhere and pooling at the lower plenum.

 

[thegipper]

My bad motor I just swapped out looked about like yours. My donor engine has about half that amount of carbon/gunk crap in it. I wouldn't worry too much about it but change your PCV and grommet anyway.

 

[Daneums]

I've seen worse pics of the plenum runners, FWIW mine were dark honey-colored when I pulled them so a bad PCV at some point in the vehicle's history makes sense.

Just on a hunch, what does your throttle body look like?

I've cleaned it on the vehicle before, and I'll be cleaning it again and puling the IAC valve off and cleaning it too before reinstalling

 

[Daneums]

If you're sure it's fuel (hard to mistake that), then you probably have a bad fuel pressure regulator.

What happened with mine was the little valve in it failed and it drained fuel into the air baffle from the hose running under (between upper and lower) the plenum. My air baffle was full up, to the point of being sloshy. The plenum is right between the baffle and the throttle body, so I would not be surprised if fuel wound up in there.

The FPR is at the very back of the fuel rail, driver's side, unfortunately.

99% sure it was fuel. Clear liquid smelled like gas... I'll check the baffle later tonight. Plenum is still off so fuel rail is easily accessable right now. Thats the reason I would like to figure out the problem now

 

[Daneums]

check the fuel return hoses going to the plenum. it could also be leaking from elsewhere and pooling at the lower plenum.

I dont see or smell any fuel leaks, although my valve covers are pissing oil so they could be hiding it.