Fuel issues

[crash]

Finally got the car to the dyno and found out that I am running out of fuel pressure above 4500 rpms. I have just dropped the gas tank to investigate.

I am running a vortech with a 3.33" pulley, SCT 2400 MAS, 60 pound injectors, and an Aviator fuel pump rated at 271 lph.

Has anybody else used an Aviator pump? I think I might be sucking the fuel basket dry.

Here is a pic of the stock versus Aviator pump.

One potential issue is that the Aviator pump has a barbed fitting. The seal on the fuel line is where I drew the black line and it is not tight because it is
narrower than the stock fitting. Could this be where I am loosing fuel pressure?

Any other comments?

Thanks

 

[HOTLNC]

Finally got the car to the dyno and found out that I am running out of fuel pressure above 4500 rpms. I have just dropped the gas tank to investigate.

I am running a vortech with a 3.33" pulley, SCT 2400 MAS, 60 pound injectors, and an Aviator fuel pump rated at 271 lph.

Has anybody else used an Aviator pump? I think I might be sucking the fuel basket dry.

Here is a pic of the stock versus Aviator pump.

One potential issue is that the Aviator pump has a barbed fitting. The seal on the fuel line is where I drew the black line and it is not tight because it is
narrower than the stock fitting. Could this be where I am loosing fuel pressure?

Any other comments?

Thanks

There should be a hose clamp on that outlet, barbed or not.

 

[crash]

Found the problem!

I just did a little experiment.

I filled a 5 gallon bucket with water. I put the aviator pump alone in the bucket and ran it for a minute, pumping into another bucket. There is no way that fuel pump cannot keep up with the fuel demands! I got about a gallon after 1 minute.

Next I put the aviator pump back in the basket assembly and put the basket in the bucket. I made sure the basket was not completely submerged to prevent it from being filled from the opening on the top. This way the only way it can be filled is from that valve on the bottom, just like in the tank. I turned on the pump and after about 5-10 seconds, the basket ran dry and could not fill fast enough.

The aviator pump flows too damn much!

 

[mlschultz]

I have the same type of problem with my GT supercar pump and KB BAP set-up. I have found that running the car with no less than a 1/2 tank fuel works best while under WOT.

 

[logres]

I have the same type of problem with my GT supercar pump and KB BAP set-up. I have found that running the car with no less than a 1/2 tank fuel works best while under WOT.

You would think some engineers somewhere would have addressed such an obvious problem...

 

[Mad1stGen]

I have the same type of problem with my GT supercar pump and KB BAP set-up. I have found that running the car with no less than a 1/2 tank fuel works best while under WOT.

It's most likely because the basket has been cut out and the pump is sucking fuel directly from the tank, not thru the basket, typical mod in a mustang world.

No other solution to be honest, unless you want to weld couple sumps on each side of the tank and use an external pump.

 

[crash]

Question for you guys. What is the purpose of the area circled on the fuel basket? It is connected to the fuel feed line.

 

[billcu]

That looks like the filter to me. Some people call it a sock. It keeps chunks of stuff out of the fuel pump.

 

[crash]

But that is separate from the fuel pump and the fuel pump sock. The fuel feed line has 2 connections, one for the fuel pump, and one the above picture.

 

[crash]

Here is a picture of the fuel feed line one connection for the output of the fuel pump and one connection for the area circled above.

I am wondering is there any problem with only having the fuel pump connected to the fuel feed line as in the picture below. I had to do this because of the fitting on the Aviator fuel pump is smaller than then stock pump and it was loose in the stock connection above.

 

[Mad1stGen]

The stock sysem is pretty complicated. The pump creates vacuum when pushing fuel out of the basket, and that vacuum is used to suck fuel from the tank into the basket via that extra nipple. You need the stock setup with the Y for it to work properly, or cut out the basket and live with the minimum 1/2 tank deal on long right turns

 

[crash]

Huh? The pump cannot create a vacuum in the basket. The basket is not sealed. The basket is fulled via the one way valve on the bottom of the basket.

 

[budpytko]

OK...I think he means "an attempted vacuum"..... caused the same effect tho....As we are not in outer space, I doubt that he meant a full vacuum.

 

[Mad1stGen]

Does suction sound better ? hahaha

You're not correct about how the basket is filled.
The Y was there for that very reason, the basket is being filled when the pump runs.
Trust me, we've been down that road many times. Put the Y back in place, and watch it fill the basket.
The basket should be full all the time, regardless of the fuel level, as long as there is enough fuel in the tank to fill the basket. It helps cool the pump down and extend it's life.

 

[crash]

That makes more sense. I guess I just don't understand how that would fill the basket, being that it is connected to the output side of the pump.

 

[crash]

Now I get it! I had to drop the tank again to figure this out. When the pressure is above a certain point, some fuel flows through that "other contraption" and acts as a venturi to suck more fuel into the basket.

You can see the fuel bubbling out of that hole. I have the return line kinked in my left hand in the picture so fuel is just dribbling out. The basket was filling. There was only about 1" of fuel in the basket, (3 gallons in the tank) but you can see in the pic that it is at about 3" deep and rising.

Now when I unkink the hose, there is obviously no fuel being sucked in.

Now time to put the car back together and go to the dyno.

 

[sleeper]

Are the pictures dead or is it me?

I could use the pics... I might be having the same problem.

 

[budpytko]

Must be you, I see 'em.

 

[sleeper]

I can see them from home. Must be a work thing.

Anyway, my '93 doesn't have any kind of basket like that. I think it might have some baffles inside but I guess I just didn't look all that close when I had it out.