Opinion's on fuel pressure

[Pro Street Belvedere]

Guys,

When I start my car I have 6+ pounds of presure, drive for a while, get the car back home and check the fuel pressure gage under the hood and I'm at
3 lbs + -.

Im thinking dirt in the filter, maybe electric fuel pump getting tired, pump make a lot of noise (not sure if it is any louder than it was before)

Any body have this issue and found a fix?

Thanks, Butch

 

[68pplcharger]

Definitely a fuel flow problem. Could be a clogged filter or clogged fuel pump inlet. The pump could also be bad. I would try bypassing the fuel filter first. A quick test is to turn the pump on and let an open fuel line run into a gas can with a graduation marks. Time how long the it takes to fill one gallon. Get the rating from the manufacturer for the gal/hr. The pump should be pretty close to that rating. If it's not then there is a clog somewhere in the system.

 

[Cranky]

What pump are you using and are you using a regulator? Do you have a fuel return line in the system?

 

[Pro Street Belvedere]

What pump are you using and are you using a regulator? Do you have a fuel return line in the system?

Its a holley pump, I have a fuel regulator and no return line
Fuel cell is vented

Before I vented the cell, I did a burn out & the car shut off after, I checked the fuel gage & had less than 1 #, then I vented the cell.......I figured that was the problem,

The motor is a 440 super charged so it drinks a lot of fuel, the car has an in line filter between the cell & the pump, I just ordered a fram screw in filter, I figure it won't hurt.

Thanks for the help, Butch

 

[Cranky]

Always push through the filter and not pull through it. Try fixing that and see it if helps any. The pump is better suited to pushing fuel and isn't as effective trying to pull it through restrictions such as filters.

 

[fugly]

you can do alot better than a holley pump on something like that- if you have a switch try clicking it off for a few seconds when it loses pressure and then back on - if the pressure comes back up for awhile, something is clogged, otherwise its the pump

 

[65-440]

i have heard some horror stories on those holley fuel pumps ..... not the most reliable

 

[Pro Street Belvedere]

Great thoughts guys,

So I should plumb the filter after the pump, and be looking for a different pump........what brand and I assume at least 120gph?

I will give it a test, by turning it off & on next time the pressure drops

Thanks again for your help.............you Mopar guys are the best!!!!

Butch

 

[Meep-Meep]

Yeah, you want the filer on the pressure side of the pump. I'd try one thing at a time. You may not need another pump.

As a side note, the pump should be mounted low so as to have a nice gravity feed to the inlet. Also, I believe Holley and Carter specs their carbs for 7.5 PSI and not more. Having the correct pressure will maintain the proper average fuel level in the bowl just like the carb was calibrated at the factory.

 

[SUPERSTOCKRACER]

i have heard some horror stories on those holley fuel pumps ..... not the most reliable

i've used holley blacks for years with no issues.
but my fuel pump of choice now is product engineering with filter.
here's my setup,

 

[Meep-Meep]

Oh, another thing you might try is to take the Holley pump apart to inspect it. I'm pretty sure there is some sort of pressure relief bypass in the pump body and it might be full of crap causing issues. Just a thought.

 

[65-440]

i've used holley blacks for years with no issues.
but my fuel pump of choice now is product engineering with filter.
here's my setup,

looks like a nice setup you got .... i havent had experience with the holley pumps, just hear-say ... i know a buddy of mine went through 3 in a row, all 3 of them siezed up in a relatively short period of time. now he runs a mallory with no problems ...

 

[SUPERSTOCKRACER]

65-440, its the only way to go and i run a return system up front as well.

 

[65-440]

SSR, thats my plan for this winter. new pump, regulator and also run return line .... is that a matching regulator to the pump/filter ?

 

[SUPERSTOCKRACER]

SSR, thats my plan for this winter. new pump, regulator and also run return line .... is that a matching regulator to the pump/filter ?

let me know if you want that setup, i'm a dealer for them. great pricing and free shipping.
its all product engineering products. they have a few different pumps to choose from. let me know.

 

[65-440]

thanks bro, will def. let you know when the time comes ... then we can talk $$$$$$$ !!!

 

[moparmarkk]

Tell me more about this...going to be out of town...heading the Garlits...showing my 65 Belvedere...440...This looks great can you PM me in a few to give the details?
Thanks
Markk

 

[Stumper]

Trouble with pushing fuel through the filter is that you have unfiltered fuel going through the pump? Not the best thing for your pump if it sees any contamination. I'm no expert but also not really sure of any true benefit to having the filter upstream? As long as the pump has enough NPSH (net positive suction head) which most do, it should pull as easy as push (assuming you don't mount it on top of the car).
Has anyone ever documented an actual benefit on a dyno switching between pre and post pump filtering? My set up is currently pre pump filtering but I cam also getting ready to make some plumbing changes to install a shut off valve so I can pull the filter for cleaning without draining the fuel cell. If there is a real benefit to relocating the filter I may give it a try.

 

[fugly]

actually most of the big pumps require the filter BEFORE the pump or they will not cover damage- this is th point behind th low restriction filters-Call aeromotive/aerospace and ask where ithey expect it.....

 

[HEMI-ITIS]

Which holley pump and what filter?Is the fuel in a stock style tank or a cell?Is the fuel fed from a rear sump or sucked out the top?What size line from tank to pump & pump to regulator?Blown BB wedge,approx HP?Do you race the car at all?What are your future plans power wise?If you are to upgrade the system,overkill it and NEVER worry again.When I finally upgraded my system way back when,the car picked up almost a half a second:icon_hang: