- Jul 22, 2015
- 2,724
So today, I figured out that my Sierra's new (but recurring) 'crank / no start at initial try' isn't due to a tuning issue, etc. - it's likely an issue with the check valve in the fuel pump going bad (fuel system loses pressurization). Solution is to apparently replace the pump. Which, while it's an issue... is also an opportunity. And while I could get by in the short term by pressurizing before starting (like we do when depressurizing for fuel work, etc.), I think I'd prefer to just fix the problem, rather than have to remember a workaround, every time I get in the truck.
I know it's easy enough to drop the tank & put a like-for-like stocker back in (and from what I recall of everyone replacing in their 360s, it's "Bosch, ACDelco, or don't even bother doing it"). There are also 'plain pump' assemblies (of which Walbros is one; I'll get to them later).
The stock pump for my truck is listed at about 60-ish gph max; normal duty cycle comes out to about half of that.
I'm thinking about getting a beefier pump - not that I need it now, but if I add boost (turbo) later on, that's one more thing I won't have to replace, when the time comes. So, I figure... replace it now.
Doing some reading, the flex fuel-capable stockers are supposed to flow really well - 600-700 HP trucks do just fine with them. So that's another option (although I'll have to do the homework on adapting one to my '03, which has a 'return' fuel system w/ the regulator on the intake; those went away in '04, and the only 'classic' that ever got a FF-capable pump was the '07. But I know *someone's* done it, so I don't have to reinvent the wheel - just find their notes / how-to.
The 'go-to' option for those running boost on full-size trucks seems to be a Walbros brand pump -- and those apparently come as 'just' the pump, not the entire module. I still have a lot of reading to do in this area. These are racing (?) pumps; 300-450 LPH and up. I don't think I need that much flow, to be honest, so this option's going to be on the back burner, right now.
I already have a brand new set of FF-capable 50lb injectors (Delphi), waiting to be installed (the stockers are rated at 25.5, and they'll eventually have to come out. More on this later, when I get ready to swap the intake.) Right now, I'm still running the stockers, and not noticing any bogging / evidence of fuel starvation, etc. I'm also not romping hard on the motor for another 500 miles, yet. But since the fuel pump issue has now come to light, I figure to get that upgraded now.
I also want to be able to run E85 on occasion, so a FF-capable pump would help with this. I'd still need to get a fuel composition sensor to make E85 work, but that's pretty much all I'd need (and enable it in a tune, of course)
Yes, I realize I really didn't ask a 'question', here. If you have input, feel free to share (including if having that extra flow will cause an issue w/o really 'needing it', at the moment). Last time I dealt with a fuel pump was the mechanical type, on a SBC, about 30 years ago. So I'm a bit behind the curve, here.
I know it's easy enough to drop the tank & put a like-for-like stocker back in (and from what I recall of everyone replacing in their 360s, it's "Bosch, ACDelco, or don't even bother doing it"). There are also 'plain pump' assemblies (of which Walbros is one; I'll get to them later).
The stock pump for my truck is listed at about 60-ish gph max; normal duty cycle comes out to about half of that.
I'm thinking about getting a beefier pump - not that I need it now, but if I add boost (turbo) later on, that's one more thing I won't have to replace, when the time comes. So, I figure... replace it now.
Doing some reading, the flex fuel-capable stockers are supposed to flow really well - 600-700 HP trucks do just fine with them. So that's another option (although I'll have to do the homework on adapting one to my '03, which has a 'return' fuel system w/ the regulator on the intake; those went away in '04, and the only 'classic' that ever got a FF-capable pump was the '07. But I know *someone's* done it, so I don't have to reinvent the wheel - just find their notes / how-to.
The 'go-to' option for those running boost on full-size trucks seems to be a Walbros brand pump -- and those apparently come as 'just' the pump, not the entire module. I still have a lot of reading to do in this area. These are racing (?) pumps; 300-450 LPH and up. I don't think I need that much flow, to be honest, so this option's going to be on the back burner, right now.
I already have a brand new set of FF-capable 50lb injectors (Delphi), waiting to be installed (the stockers are rated at 25.5, and they'll eventually have to come out. More on this later, when I get ready to swap the intake.) Right now, I'm still running the stockers, and not noticing any bogging / evidence of fuel starvation, etc. I'm also not romping hard on the motor for another 500 miles, yet. But since the fuel pump issue has now come to light, I figure to get that upgraded now.
I also want to be able to run E85 on occasion, so a FF-capable pump would help with this. I'd still need to get a fuel composition sensor to make E85 work, but that's pretty much all I'd need (and enable it in a tune, of course)
Yes, I realize I really didn't ask a 'question', here. If you have input, feel free to share (including if having that extra flow will cause an issue w/o really 'needing it', at the moment). Last time I dealt with a fuel pump was the mechanical type, on a SBC, about 30 years ago. So I'm a bit behind the curve, here.