Plenum intake issue

[Saab84mw]

Here is where I’m at I have installed a newly rebuilt engine (L29) in big green finally got the distributor set at 0° where it needed to be was having a slight fuel smell under the hood figured it was because the Distributor not being set correctly.

Ted who is helping me set a distributor said he also smelled a strong raw fuel smell under the hood when the truck is running never had this issue with the old engine.

I have checked the fuel lines and (new)fuel regulator coming up to the back of the intake And don’t see any fuel leakage when I got back home from dinner tonight it was dark I checked under the hood with a flashlight and what I think I see is where fuel is coming out between the platinum and the intake has anyone had this issue before?

My thoughts are I don’t have the plenum tighten down enough, in the past when I’ve taken it off and put it back on I just tightened it to where I thought it should but this time when I put it together I torque spec everything oil pan, Exhaust manifold, intake manifold and plantain to the torque specs.

The fuel smell is very strong under the hood and it’s only there while the truck is running or after you run the truck and you stop and you open the hood if it sets overnight the smell dissipates.

When I start the truck fuel pressure goes up to 55 psi when I turn the truck off and slowly drops down to about 30 psi if I let it set overnight with the fuel gauge on it the next morning it reads15 psi.

thanks in advance for any thoughts on this issue.

1999 K2500 Suburban L29.

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[SAATR]

Sounds like an injector or injector seal issue. Better pull the upper plenum and inspect the fuel system before something catches fire.

 

[Saab84mw]

Sounds like an injector or injector seal issue. Better pull the upper plenum and inspect the fuel system before something catches fire.

I just replaced all that with the new engine new injector O-rings check the injector rail put new clips on it looked underneath there and everything’s tight there’s no fuel coming from the inside that I can see.

The thing is it’s Evaporating so fast I can’t really see where it’s coming from exactly.

 

[SAATR]

So where exactly can you see liquid fuel? At the gasket between the upper and lower plenum? From the rear of the valley between the upper and lower manifold? I'm not clear on where you are seeing fuel.

 

[Saab84mw]

So where exactly can you see liquid fuel? At the gasket between the upper and lower plenum? From the rear of the valley between the upper and lower manifold? I'm not clear on where you are seeing fuel.

that’s the issue I can’t see the fuel the only time I seen any remnants of it was at night time when I shined a flashlight and I could see the residue between the upper and lower intake

 

[SAATR]

that’s the issue I can’t see the fuel the only time I seen any remnants of it was at night time when I shined a flashlight and I could see the residue between the upper and lower intake

The only thing carrying fuel in that area should be the fuel rail, lines, regulator, and injectors. If you've visually inspected the supply and return line at the back of the intake and the regulator, then all you have left is the fuel rail and injectors. The fuel vapor return system can make a strong fuel smell if it is left open or damaged. If you can eliminate that with your eyes and nose, then you must have an issue under the plenum. It's all that's left.

 

[Saab84mw]

The only thing carrying fuel in that area should be the fuel rail, lines, regulator, and injectors. If you've visually inspected the supply and return line at the back of the intake and the regulator, then all you have left is the fuel rail and injectors. The fuel vapor return system can make a strong fuel smell if it is left open or damaged. If you can eliminate that with your eyes and nose, then you must have an issue under the plenum. It's all that's left.

Thanks just didn’t wanna have to pull that Plenum off again but I guess that’s gonna be the next thing I do let you know what I find

 

[Saab84mw]

I found the issue it was one injector all the way in the back and it was only leaking at high pressure.

I had already put new O-rings on the top and bottom of the injectors so I pulled it off and cleaned it again and moved it to the front of the fuel rail so I can keep a eye on it.

So far so good now to fix the A/C (will it ever stop?)

 

[SAATR]

I found the issue it was one injector all the way in the back and it was only leaking at high pressure.

I had already put new O-rings on the top and bottom of the injectors so I pulled it off and cleaned it again and moved it to the front of the fuel rail so I can keep a eye on it.

So far so good now to fix the A/C (will it ever stop?)

Glad you found it. And no, it never stops. Just the charm of an older vehicle.