So, what is a fuel sump and what does it do? That pump under my floor is the second one for the truck... and I don't think it's gonna hang in there much longer. Also, I'm thinking my lengthy starting when cold (as in, sitting for awhile) is due to problems from this. It starts really quick when it's been off for a few minutes so, I'm wondering if it's a pressure issue... my GP's and GPR are fine. The starter is a little weak, but not shot enough to justify a new one yet. But anyways, I've really been wondering what a fuel sump is and what it does? Will it help that pump under the floor? Will it eliminate it completely? Is there any alternative to it? Thanks guys,

Jon

 

I'll take a stab at this.
A fuel sump, or pocket, is added to the bottom of the fuel tank. The fuel line, that feeds the fuel pump, is moved from the top of the fuel tank to the bottom at this sump. The sump collects the fuel at this point and allows gravity to help push the fuel to the pump instead of the pump having to work to draw it up and out the top of the tank. A larger line is usually installed from the tank to the pump to aid delivery.

 

You may have a fuel problem, but I would check out the other possibilities first. You said the starter is a little slow. How old are the batteries? Battery connections, ground wires, connections on the starter? A slow starter will take longer to start your truck. Weak batteries will also make the fuel pump work slow. How does the truck run once started? If it's a fuel delivery problem you should notice something in the way it runs, not just at start up. The reason I'm suggesting that you check all these possibilities is that I would hate to see you do a fuel tank modification and that not fix the problem.

 

It runs like a champ... that's a good thought. I can't figure it out. The batteries are good... pretty new actually. What I don't get is how the voltage "seems" to drop whenever the truck is cold, but it really doesn't. So, it's usually slow to crank. I've checked the voltages before, during, and after cranking with a volt meter and the voltages a 12 something cold, and it dips down to about +-10V and then it jumps up to 14 after it starts. The starter will turn pretty quick, but only if the batteries are fresh off the alternator. The terminals are brand new, I've cleaned the ground connections and that helped some. The starter is a Napa special so I'm sure that's half of it. The pump has made that "dry plastic gearbox" whine several times... so I don't know if that's going bad or what. But I know my batteries and connections are good. But that's a good thought about the fuel supply... that must not be the problem. And the only things I can seem to come up with that in mind are a weak starter and/or inline fuel pump. Any other ideas?

 

If the starter is weak, it should (but not always) crank slow even if it's warmed up. I would check the voltage on the batteries after you shut the truck off. And then compare it when you go and start it in the morning. It sounds like you might have something drawing some current from the batteries while it's shut off. Have you added any electrical devices recently? Sometimes an alternator can draw current when shut off if it's going bad.

I guess in a nutshell, I would fix the slow cranking first, and see if that solves your problems.

 

I've been trying to figure out what's up with the slow cranking... I started a thread and couldn't get any answers outta anybody. But I have read the voltages... it was in the upper 12's cold after sitting all night in the teens and low 20's. As it cranked, the voltage dropped at the lowest to 9-something, but it was 10-something most of the time. After it started, the voltage was 14-something. The alternator is a high-amp Powermaster so I doubt that's that problem. I can check the batteries again with a battery tester, but I'm almost positive they're fine. One reason I think it may be the starter is because it's rebuilt junk. I went to unscrew the nut off the mail terminal on the solenoid and all the guts spun inside the solenoid housing. Can't be good... I was gonna go for a Powermaster starter so it'd have more kick than stock. I just can't figure it out...

 

A bad selenoid will not allow for a good connection. I believe you have found your problem, or certainly "A problem."

 

Well, I'm waiting for it to either completely go out, or I have enough money to justify ditching it. I'm 17 and still in school with only a Saturday job so, I think you might understand where I'm coming from. Is there any way I can test it to see if the problem is the solenoid? Is there any industrious fix I could do? I'm not afraid to tear into stuff... I did that lock fix where I had to replace the resistor in the motor with a solid piece of metal. It was tedious for sure, but well worth the money I saved!

 

But back to the fuel sump idea, what would it do most for me? Other than keeping the pump from working too hard, does it do anything else for me? Also, should the inline pressure pump make that "dry plastic gearbox" whine (like those cheap plastic toys)? It does that every once in awhile... is there anyways I could eliminate that pump? Are there any alternatives to it? Sorry for the pile of questions...

 

Here's a good thread
https://www.ford-trucks.com/forums/8...questions.html

Here's another thread
https://www.ford-trucks.com/forums/9...fuel-mods.html
I believe post #4 list a website for the kit described in both posts.

 

JanathanN,

Try keeping your fuel tank above 1/2 tank for a while. There is a problem with the the fuel pick up ( in the tank ) on these trucks. Keeping the tank level higher will prevent the pick up from sucking in air. There is a Mod. to correct this, but it requires you to remove the tank. See if this helps, also try a fuel pressure gauge at the fuel bowl. keep us posted.

 

Hmmm... that one fellow mentioned kinda what mine is doing. He's saying his truck started faster after the mod. That's kinda what I was saying... it's kinda like the fuel looses it's "prime" or whatever and the pump can't seem to get the fuel up to the engine fast enough during starting. That's why I'm thinking that if I start the truck, run it for ten seconds or so, and then shut it off before the batteries get juiced up, it'll start quite a bit quicker, even with a slow starter (another menace that I wish I knew what it was). So, I'm thinking my inline pump isn't keeping up right at first. These mods seem to address this problem as well. I really don't like the notion of having to cut a hole in my tank and have that sump hanging down. Knowing me, I'd mess it up someway or another... but I can't figure what exactly the CCK, RR, Harpoon, and Hutch mods I was reading about are. With that in-tank pump, is that in adittion to the pump I have now, or am I just moving it? I would rather not have ANYTHING in the tank... which of those mods do that? I just wanna make my truck work better...

Bob,

That's interesting... I run my tank to E just because I try to make my tank go as far as I can so I don't have to fork out the money as often... 38 to 40 gallons get's expensive! But you're saying that I could be messing stuff up by doing that? These mods seem to be cheap too... any suggestions?

Jon

 

JonathanN,

Here is a link to guzzle http://www.guzzle7pt3.com/hutch.php check this out, you can do it for near $50.00

 

Oh nice... Thanks! So, with the elimination of the air leaks in the quick-disconnects, why would I wanna put the inline pump in the tank? What would that do/change? Also, doesn't that cause the inline pump to be BEFORE the fuel filter? If that's the case, how do you keep from destroying the pump with contaminants? Also, he removed the mixing chamber... what did that do originally that made him decide to take it out?

 

Read his complete write up, it will explain everything step by step. no need for the addition of a second pump. you use the same OEM pump and add a $15.00 NAPA filter in front of the pump.