How many of you have done various fuel delivery system upgrades on your truck. This seems to a constantly recurring source of problems.

 

upgraded lines to 1/2" all the way to the lift pump(due to sucking air from somewhere). lift pump in the works, not sure whether i'm going piston or electric yet.

 

Walbro system in parallel with a low pressure piston lift pump, through a Fleetguard 1212 filter (a little bigger than stock) into a GDP Big Line Kit. The Walbro has a 1/2" pickup in the tank. I can't get it to drop below 15 psi.

 

Well, nobody took much of an interest in this, so I'll just go ahead and finish it up with a point-by-point outline. I replaced or upgraded all mine, literally lock, stock and barrel - because the stock fuel system on these trucks just plain sucks. From the tank, onward:

1) Tiny stock pickup. If you ever have the opportunity to take the tank down for any reason, spend another couple minutes to pull the sending unit and have a look at it. The actual pickup itself is SMALLER than 5/16"! BC847 brought this up a couple years ago, along with another major restriction in the filter plumbing. I don't care if you put one inch I.D. fuel lines on it and and pull with a steam powered 500hp hydraulic pump, it ain't gonna flow enough fuel. Simple as that. Don't spend money on other upgrades if you're looking for much more than stock power until you have this problem addressed by either enlarging it or tapping the tank in some other way.

2) Tiny fuel filter. Pretty simple. Bigger is better when it comes to flow. And the time it takes to clog. Why buy another stock filter when spin-on bigger replacements are available? Better yet, replace it outright with a head that flows good and an ever bigger/better filter? Easy DIY stuff, if you're so inclined.

4) Worthless, problematic fuel heater. Is it getting cold again this year? edit, happens every year, right along with the fuel heater leaks. You can almost mark your calendar with the increase in fuel heater-related posts. I'd recommend ditching it entirely and save yourself the headache, unless you're drivng in Alska or the far northern tier. Even then, the thing most likely to save you from gelling is a fuel add, not that tiny plastic heater. I drove without mine all last winter in sub-zero temps on at least one occasion, no problem. This year I'm learning how to live without the grid heaters, but that's another post.

3) Crappy, small steel fuel line. 5/16" is fine for a stock truck. That's all, no more. I can tell you this with certainty from experience in the course of observing fuel pressure trends though many power and fuel delivery mods. I built my truck to run full bore for towing heavy in the mountains around here. There's many things you can do to control EGT after you start turning up the pump, but only one will guarantee fuel delivery for extended, high power pulls: bigger fuel line. Although I haven't seen them, I hear some of the connectors ain't the greatest either. Did I mention "steel?" And rust....

5) Inadequate pump. Again, Dodge built to the minimum standard. It'll support 160hp all day long. Just maybe fill your crankcase with diesel when it finally decides to come apart. And it will, sooner or later. Put a piston pump on it, never buy another and stop worrying about it. Or get fancy with electrics, bypass regulators and higher pressures, whatever. Just lose the stock pump.

So consider looking at some of this stuff a little closer, unless you want to keep posting about the air leaks, pressure problems, clogged filters, etc. etc. None of these things are particularly complicated or difficult for the even moderately competent shade tree mechanic to install/upgrade.

Got fuel?

 

I dynoed 455 and did my 13.34 1/4 with the stock fuel lines and piston lift pump only. I was very surprised to say the least when I removed the fuel pickup from the tank.

A kit may be on the way from Airdog for 1st gens.

 

Ever try dyno'ing west out of Denver up I-70 with 6k behind you?

 

If a 7000# 26' fifth wheel camper counts; yes.
It will go faster than the POS trailer tires they make nowadays can handle.

 

Ever run the 1/4 mi. with that trailer behind you?

But seriously, does it still have the stock fuel line from the tank? I believe you can cool alot of fuel with that setup, head, etc. Even so, I'd be curious to know what the fuel pressure is at the VE inlet as you go through the traps. A 1/4 mi. might tell the tale, but I doubt a 5-10 sec dyno run is enough for fuel delivery to even come into play as long as the filter's not plugged....

 

Maybe OEM supplied trailer tires but I know that those goodyear load range G 215/85R16 are not too shabby. How fast do you need to tow? lol?

 

Well, I run what amounts to a bombed OEM fuel pick-up. Pretty-much a stock assembly with enlarged ID fuel passages. As such it allows any manner of truck positioning (leaning one way or another) without starving the engine while the majority of the fuel in the tank, is at one end or another of the tank. Works really well . . . . to a point.
In my case, in the full race setting, on launch all the fuel stands on the rear most wall of the tank. Same thing in the fuel cannister (that which holds the pick-up assembly). The increased pumping capacity of the bombed fuel system quickly sucks fuel from that the pick-up can reach to the point of sucking air. As such, best be prepared for the engine to need re-priming at the end of the track (17mm wrench to burp the injectors ).
The only real fix for that is the draw-straw mounted in the very rearmost of the tank. It works best with acceleration. Deceleration . . .. not so much.

Crap! A vicious cycle.

 

Here's a couple ideas: Run with the tank over half full. -or- bulkhead connectors front "and" rear, with float valves on the inside.

 

My point is Ace I never had a problem with the stock fuel system even though upon looking at the pickup, one would swear I would have.
Would it suck down to zero sometimes? Yes.
Did it ever spit or sputter? Never.
In all honesty, I had tried to floor it for long periods empty or loaded and no matter what I was either way too fast, ran out of road or too high egt's before any hint of a problem.
Again, I was very surprised when I took it apart to enlarge everything to find the the pickup to be that small.
IMHO, if a person is below a true 375 uncorrected diesel only hp, install a piston pump and the heck with the rest. It would be very seldom you will have the pedal floored for long to hurt anything. What's it take to cruise down the highway empty; 50-75 hp? Loaded 150-300?
I am only now experiencing some problems since installing larger lines and pickup. I am sucking air somewhere but have yet to find the source. I am thinking of just installing a bulkhead in the bottom and gine it a whirl.

 

I understand completely. But (big but) I'll wager if you could come up with a setup and load scenario that'll allow you to pull hard in that 350ish range long enough, it'll start running out of fuel with 5/16 line.

Nothing really factual to base that on, except conjecture and what I would exptrapolate from what I've seen on my fuel pressure gauge.

 

I also believe that's the "practical" truth. You do reach a point of diminishing returns trying to "optimize stuff," and I usually don't see it before I'm way too far into it.

 

Agreed.