Wondering if there's any rhyme or reason to LSJ fuel buckets- or "fuel pump & housing assembly" as some call it, to have a venturi pump or not. I was expecting to find a venturi pump on the bottom of my bucket, like the first pic, but instead found a setup like the second pic with a prefilter at the bottom with a diaphragm in the bottom of the bucket that presumably seals off the bucket inlet when it's not covered in fuel. I was expecting to find a pump like the one in this post.

Is one more functional than the other? Will a 340lph pump outflow the diaphragm setup, or is a 340lph pump that also feeds the venturi going to provide a more stable fuel supply?

 

its a turbine pump with a prefilter sock

 

Thanks for the quick feedback. I'm not so much concerned with the pump as the canister. For what it's worth, Rock Auto shows both types of canisters for 06 and 07 Cobalts. I understand 05 LSJ's typically have a different module with a weaker pump. But I'm looking to learn about venturi vs non -venturi buckets on 06/07 LSJs.

 

in your goblin, depending on mods, you are going to want to upgrade to a Deatchworks or Walbro pump anyway

 

It's twincharged now and I bought a 340lph with a venturi pump fitting thinking I had a bucket with a venturi pump. Turns out I have the other style. I'm unsure whether to pick up a canister with a venturi pump, exchange for a pump without a venturi pump fitting, or do something else. If the bucket without the venturi pump is prone to being emptied with a bigger fuel pump, I'd probably swap for the venturi pump bucket or go another direction entirely like running some hydramat.

 

I would just skip the inlet connection and get a corrugated fuel hose for the outlet

 

I'm not sure I follow, sorry. The Racetronix RXP340TE is a drop in replacement for my stock pump, aside for the venturi fitting. It engages the inlet at the bottom and the outlet at the top of my bucket just like the stock pump did. Are you saying I shouldn't reuse either the stock inlet or outlet?

 

leaving the inlet disconnected isnt an issue. The outlet will need to have a flexible hose on the pump barb and a clamp

 

My stock fuel pump doesn't use a clamp and the new one fits the same. I don't see a reason to not reuse the stock hose so I will probably leave it unless we think it won't hold up?

 

You wont be able to get the hose off the factory pump without cutting it, it is heat shrunk on there

 

I'm pretty confident at this point there are two different buckets. I assume the bucket with the venturi pump on the bottom uses the hose setup you're referring to with the heat shrunk hoses.

 

ive never seen a fuel pump assembly with what you are describing on any LSJ

 

Let me ask this, then. I assume if you've not seen a bucket like mine, that you've only worked with the other style that has the venturi pump on the bottom and presumably also has the corrugated hose heat shrinked to the pump, like the picture below that I pulled from the other thread linked in the first post. With this style bucket, is starvation an issue with a 340lph pump if the venturi function is retained? Thanks.

 

ok, so lot to unpack here,

1. Most LSJ's (unless CA emissions car) have the traditional fuel pump canister not what is shown in your pic from the other thread
2. The pump that you are referring to as a venturi is the California emissions car (although some Canadian models had this as well). not a common setup for LSJ cars
3. Easiest way to tell is the standard pump canister has 2 lines coming out of the top hat, the below picture shows only the one, in fact you can see the tank is molded for the second line that wasn't used on that OP's car
4. This "Venturi" design utilizes a different fuel filter and has no return back to the tank; this design is not good for a modified fuel system as it simply cannot return the fuel to the tank fast enough. this will cause pump starvation
5. Only early 05 cars had the issue with sucking the canister dry. mine did with a DW320 pump on ethanol. it was resolved with a surge tank and inline pump in addition to the in tank pump. Reference my video where i describe it.

Check the tank to see if it has the dual black fuel lines routed and recessed in the top of tank.

 

My hat has two ports, a feed and a return.


At the bottom of the bucket on the outside is a prefilter with a diaphragm visible when the prefilter is removed.


At the bottom of the bucket on the inside is another prefilter with a spring that appears to act upon the diaphragm.


I went ahead and ordered a 340lph pump that should be dimensionally identical to the one that I currently have that has the venturi port barb on it. I don't know if my bucket or module is really that unique, but at this point I want to get the car back together. I'll post up the results of the swap at some point. Thanks for your help.