BWard said:
What exactly are the benefits of the hutch mod?
Air plus diesel injectors equals:
1.) Poor, uncontrolled timing events;
2.) Poor, uncontrollable fuel pressures;
3.) Damaged, scored, and otherwise beat-up injectors (and at $1,600 a set, this one is REALLY big!)
All of this results is rougher running, less power, and more noise.
In the 99+ ford powerstroke, the fuel system had several points in which air could infiltrate the fuel system and cause air bubbles in the diesel supply. It also had a few points where pressure differentials "freed up" otherwise entrained air in the diesel fuel (like shaking a can of soda pop). The result of many very intelligent men trying to find a way to fix this problem was the Hutch Mod, named after the user name of the gent that created it, Hutchinaugusta. I'll give you a quick synopsis of what the mod does, along with it's sister mod, the "pre-pump".
The factory fuel system had a bunch of places where air could infiltrate the system, on the vacuum/suction side of the pump. Starting at the tank, there was a device commonly known as a "duckbill" that sucked in air whenever the truck was under 1/4 tank of so. If your truck makes more noise when it is below 1/4 tank, it is not just you, it is really happening because of this duckbill. The Hutch mod eliminates this guy. He is not necessary.
Moving on, there is a devilish little device inside the tank known as a "mixing valve" who's sole purpose is to mix warm fuel from the fuel return in with the supply fuel from the tank, to "pre-heat" the fuel and prevent gelling. Not only did it not work very well for that purpose, it also had the distinct problem of returning air bubbles from the return line right back into the fuel system and into the injectors. The Hutch mod also eliminates this guy, and reroutes the return fuel to the other side of the tank from the pickup, to keep bubbly return fuel away fromt eh pickup until it has time to lose its bubbles.
At the outlet of the tank, there is the first in a series of quick-disconnect fittings, which have shown to work quite well under pressure to keep fuel IN, but don't work worth sour owl sh*t in under vacuum to keep AIR OUT. The mod eliminates these guys.
Finally, the "pre-pump" portion of the mod eliminates the final two suction-side QD fittings right before the lift pump on the frame rail.
All of these guys resulted in Hutch having found that his fuel supply was almost totally foam, not actual diesel fuel.
Most have noticed distinct benefits, which include better fuel economy, less noise, smoother operation, quieter idle, etc. It will also almost definitely improve your injector life. I personally would do it again in a heartbeat.
About how long and how hard is it to do??
You have to remove the fuel tank, which is not, in and of itself, necessarily difficult. Getting it back up there will take help from a friend. It is not difficult. The tank holds on with 4 bolts. Just run it down to almost empty and let 'er rip. While you are in there, do the harpoon mod so you can fill your tank up faster. I figure it will take a decent shadetree about 4 hours (including beer breaks).
Do your homework first and decide what type of pre-pump filter to use, etc. Oh, and I highly recommend that you replace your entire pre-pump system with diesel-rated clear hose, so if you still have air, you can isolate it's source.
