I'm running a Edelbrock SX 1794 that's rated a 120gph as a booster and having no problems with fuel pressure.It's maintaining a 11.5 to 1 AFR at 6000rpm in 3rd gear.

 

Whitt- Dont you have a return system? I think returnless started in 04

 

My truck has a return fuel system.I'm planning to go with a twin Bosch 7bar fuelpump setup when I go with the 3.3 Whipple.

 

I am starting to see a trend here. We need to have a solution to this problem

 

yeh bitch to gm to go back to return or get magna to bump up to 50lb'ers standard in the kit. but i am sure that would screw up CARB.

 

All the systems are return systems. The '04+ just don't have the return line up at the fuel rail and are not manifold pressure referenced. This setup is pretty much the same as the '99+ Fbodies. They also have trouble in high hp apps maintaining fuel pressure and many solve the problem by modifying the system and putting the return line up at the fuel rails with the pressure regulator.

If you go over stuff again and replace the pump and the pressure still goes low than maybe you should look into putting a return line up at the fuel rail like the '03 back trucks. Just a suggestion if you are positive that nothing about the install is messed up after replacing the pump and checking stuff again.

I don't understand why most guys don't have any trouble with the setup like Magna sends it though. Definately makes me think there is a problem somewhere with something about the install or you just have a bad regulator.

Does your truck take a few seconds to start up or crank right over? When the o ring in my regulator was messed up on the blue truck the truck wouldn't crank over the first turn of the key. It took two tries and pressure would not rise like it was supposed to.

 

it fires off immediatly.

maybe most people just havn't been reporting problems. but now that i'm making an issue out of it, it's coming out of the woodwork. i've talked to many reputable car builders/tuners, etc... and they say all the non return type sending systems, have this issue, and the easiest way around it, is to tune. changing to a return type system, is the true cure.

I am concerned with that fact that every single non return type system, isn't having this problem. why a select few? it does lead you to think....... what variables are there? install of course, but what about design variances? build variances? ( meaning, factory build options, flex fuel, etc...etc.... )

blownchevy, was your truck a flexfuel truck? just curious how their fuel system affects this scenario.

 

Mine isn't a flex fuel. Like I said before, I never saw it to be a problem. 50 psi was enough for me to put out 445 rwhp. If you guys don't remember I ran a 3.25 pulley, cam and headers and the stock radix tune with no KR and the tune was still pig rich.

 

ok, so you're saying you were pig rich, with 50 psi of fuel pressure, a cam, and added boost? on a stock radix tune? with headers? did you have your rear o2's turned on still? cats? what were you reading on the 02's when it was rich?

 

Rear O2's were deleted from Magnacharger per my request. I had a wideband and it was in the 11:1 range still. It was leaning out in the higher band though. Not sure exactly at what rpm though. Maybe not pig rich, but it was considering the mods. I don't remember what the narrow band was reading. My memory is a little fuzzy on this since it was a while back.