I recently rebuilt the engine on my pontiac firebird V6 3.1L. There are two fuel lines that hook up to the fuel rail. One of the lines has a small cylindrical object that sits right under the linkage and air intake plenum that started making a ticking noise. What the hell is this? It cant be the fuel filter because thats under the car near the fuel tank. I have no idea what it is or why it started ticking but I guess its broken and Id like to fix it. I'll try to get some pictures up in the morning when I wake up in case you guys have no clue what i'm talking about.

Thanks in advance.

 

umm ya no idea, wake up an take a photo.....

just a side not most all feul injection makes a ticking noice so if it is an injector that would be normal. injectors are attached to the feul rails abive each cylendar maybe that is what you hear.

jeff

 

Circled in red. What the hell is that?

 

Just a dumb question here, but do you have a fuel line going into the fuel rail near the fuel pressure regulator? Are you the original owner of the car or has it had a previous owner. Next question, is that the manifold from a 3.1L or a 2.8L that had cold start injection? I have manuals for the 3.1L engines on both the firebirds and camaros for 90 - 92 and that object is not shown or listed in any of them.

 

The fuel lines screw into the fuel rail near the schreoder (sp?) valve. The pressure regulator is on top of the fuel rail towards the front of the engine and all that plugs into it is a vaccum line.

I'm bought this car used so I dont know how many people have owned it.

As for the manifold as far as I know its stock. How would I tell if its not?

 

Ya my chilton and haynes both dont say anything about it.

I might get down to the dealership on Monday and see if they can tell me what it is.

 

The round can is a fuel pulsation damper. Its purpose is to help quiet the fuel delivery system. It does this by absorbing the hydraulic hammering in the fuel rails from the closing of the injectors.

An example would be when you turn off the water faucet quickly the pipes bang. There are dampers that can be installed to prevent this, same deal on the engine.

RBob.

 

RBob, I have seen the pulsators on the fuel pump in the tanks but cannot say that I have ever seen or heard of one at the fuel rail. Is that an aftermarket affair.

 

It is actually stock from the factory.

RBob.

 

Surprising that none of the manuals mention it or show pictures of it.

 

Hey thanks rob. Thats been eating away at me for some time now. Now I guess my next question is:

Why would it have started ticking? Its obviously not doing a very good job dampening the sounds. And it never has ticked previously. Could this indicate a problem with my fuel injectors? Or maybe the dampner has some internal parts that are worn out?

Or perhaps its nothing of importance?

 

With it not previously ticking, and now ticking, then something changed. What changed I couldn't say. Perhaps the spring or diaphram in the can broke. I really don't know.

RBob.