[gregrob]

The following is part of a PM I sent a fellow user. It took me a long time, actually getting my hands dirty (god forbid), and talking with Dennis at ITP to figure out the stock system and how it all works.
I know some of you were born with this knowledge and may scoff at my elementary understanding of a stock PSD fuel system, but never the less, I needed to be educated.

I'm putting this out there so hopefully others who may not know will gain a better understanding of how the fuel system works and what ares of it need to be addressed.




I'll explain how the routing of the fuel goes from tank to bowl to heads to regulator/bowl, to return line back to tank, and the purpose/need for modifications to the fuel system.

1) Line comes from pickup in tank and runs to fuel pump

2) line leaves fuel pump and is fed into the bottom, DRIVER'S side of the fuel bowl You will see a hard line for this.

3) Fuel leaves the fuel bowl via 2 ports on the bottom passenger side of the fuel bowl. You will see 2 hard lines for his.

4) Fuel leaving those hard lines is fed to the FRONT of driver's side head and the REAR of the pass side head.

5) The Fuel then dead heads in the heads and there are check valves in each head at the feed locations. These check valves are thought to be there to minimize the affect of the harmonics created by the injectors firing asynchronously.

6) The fuel is regulated by the internal regulator in the bowl, whatever fuel is not needed is forced by the regulator and makes its way down the return line on the TOP-DRIVER'S SIDE of the fuel bowl

7) The return line from the regulator runs all the way back to the tank and is dumped in to a mixing valve, where it is mixed with new fuel coming from the tank. This preheats the fuel.

8) Areas that need addressed to eliminate (or at least drastically reduce) air intrusion, and fuel aeration are
>> a) Remove mixing valve in the tank, big source of aeration.

>> b)Remove quick disconnect fitting on the pickup going to pump. These quick disconnects seal fine under pressure, but under suction they leak air.
**Above A,B is commonly referred to as the "Hutch Mods" or also called "In Tank" or "Pre-Pump" mods.

Aside: you will also need to install some sort of pre pump filtration / water seperation as the mixing valve has 2 small filters which trap any particles that may make their way to the fuel pump and damage it.

>> c) Remove the "Dead Head" stock fuel system design by creating a flow through system which is externally regulated. This is accomplished by feeding the end of one head (doesn't matter which end) and allowing fuel to travel through the head and out the other side by means of connecting a return line from the head to an external regulator.

9) Deleting the stock fuel bowl is merely preference as it allows better access to the top of the engine, gives the engine bay a much cleaner, open look, and creates a wider choice of cheaper/better/more available fuel filter elements as opposed to the stock one.
The ideal setup IMO will use a 10-100 non-restrictive filtration system pre pump and a finer, more efficient filtration system, such as a 2 micron element, post pump.

A heated pre pump element with good water seperating capabilities is also recommended, especially for those in colder climates.

While you have access to the tank during the pre pump stage of fuel system modifications, you can cut off the vent tube that runs along the factory filler nozzle to allow the tank to fill almost completely without activating the pressure-sensitive nozzle shutoff on diesel pumps. This is commonly called the "harpoon mod". Makes filling the tank completely a breeze.

 

[Fast_Ashley]

Now if you would just pony up and buy Dennis' kit instead of dicking around.....
:swordfight::swordfight:

 

[gregrob]

I might add that Dennis at ITP diesel has all the parts needed to do every stage of the fuel system work you may tackle, including a high performance fuel delivery system.

In tank / Pre Pump kit
http://www.itpdiesel.com/store.php?crn=152&rn=276&action=show_detail

I've purchased and installed this kit and it's very nice, instructions are written well, good quality materials used and everything fit perfectly.

Regulated return fuel system
http://www.itpdiesel.com/store.php?crn=152&rn=277&action=show_detail

Bowl delete kit
http://www.itpdiesel.com/store.php?crn=152&rn=545&action=show_detail

Dennis has been more than helpful answering my fuel system questions and is very knowledgable. Thanks Dennis!

 

[gregrob]

Now if you would just pony up and buy Dennis' kit instead of dicking around.....
:swordfight::swordfight:

I eventually will when funds permit

 

[Fast_Ashley]

I just got mine last week, and my bowl delete showed up this afternoon.
I'll trade ya' for the Terminator

 

[gregrob]

NO :gun:

 

[Fast_Ashley]

NO :gun:

I'll trade ya' a common rail for it:swordfight:

 

[THEDIESELMAN]

I'll buy you a Terminator for a common rail

 

[CooterBrown]

A true lesson would have involved the name Hutch and been less of an ITP commercial IMO

 

[gregrob]

I added the term Hutch mod.

Dennis has helped me a ton with my fuel system stuff even though I've bought very little from him. He's a good guy and very knowledgable and I'm going to give him credit when I can.

 

[Haul_n_horses2]

Here is a little summary I posted a few months ago on the drama stop. Even Dennis said he couldn't do it any better.
"Sorry for such a long post but as some of this information is no longer accessible and having lived through the problem, I will recapitulate some of it's history for the benefit of those who are new to the 7.3L PSD SuperDuty truck.

One of the big problems with these vehicles is the design of the fuel system. The tank and it's associated plumbing were a common part between the gasser and the diesel engines. Gassers have to meet an emission standard based on the release of hydrocarbons into the atmosphere from the fuel system, not just the tailpipe emissions. So Ford designed a system with the infamous quick connect fittings that were easy to assemble and met the emissions standards so no HC leaks from the fittings. What they did not recognize was that these designs were disastrous for diesel engine as the air sucked in on the vacuum side of the fuel pump (either due to worn/stiff parts of the fuel pickup or leaky quick connect fittings) could exceed the ability of the fuel filter air separator and send foamy diesel to the cylinder heads where it's only route of escape was through the injectors. These problems were documented by TDS member Hutchinaugusta and he has fortunately continued to maintain many excellent photoessays here. This led to premature injector failure/wear and poor performance.

"TexasTowncar" (may he rest in peace) had outstanding studies looking at the problem and found that the cylinder pressure curve on the #8 cylinder was different from the others due in part to the sequential firing of the #6 and #8 injector. #6 stole fuel from the fill cycle of the #8 injector which was further down the dead end fuel rail. Another problem with the sequential firing of these two injectors is the effect of having split-shot injectors alternately sucking fuel and spilling it back into the fuel rail such that the agitation of the fuel results in release of air from the fuel due to turbulence. Ford/Navistar's answer to this problem was to change the #8 injector so it had a bigger pre-shot of fuel, the so-called long lead or AE injector. On early SuperDuty trucks with severe cackle the #8 AD injector was changed out to the AE (with modest improvement). Later trucks came from Ford with the AE installed. Despite these efforts, many 'Strokers found that their mileage suffered and they had unusually loud engines with cackle particularly audible in the 1400-1800 rpm range.

Several school bus mechanics and others with knowledge of previous IH fuel systems also recognized the problems with the plumbing of the cylinder heads. These had in previous IH implementations been fueled from the back of the head with fuel flowing rising forward and returning to the tank. This allowed air to pass through the fuel rail back to the tank rather than through the injectors. By replumbing the fuel system and eliminating the dead end fuel rails, TexasTowncar demonstrated that the cylinder pressure curve in #8 cylinder was more like the other cylinders and then in an experimental trial he worked with some hot shot truckers and a fleet of F350s modifying some and leaving some unmodified. The unmodified trucks had progressive loss of mileage over many miles where the modified trucks maintained their original mileage. With the unfortunate demise of TT, this data is no longer on the internet and as new iterations of the PowerStroke diesel have emerged this historical information is being lost.

So what is known:
1. Air in the fuel is bad for the pump and for the injectors.
2. Dead end fuel rails are a poor design to handle any air that should intrude into the fuel.
3. With dead end fuel rails and sequential firing of #6 and #8, the #8 injector is relatively starved for fuel leading to abnormal cylinder pressures with attendant damage to that injector and the rotating parts in that cylinder.

What can you do to eliminate the air in fuel issues?

"Pre-pump mods"
The fuel pickup is designed to recirculate any returned air if the temperature of the fuel is low. The duckbill flapper valve that sends the fuel/air mixture back into the tank can become stiff and remain open to allow air to be sucked up into the fuel pickup when the tank is low. This can be fixed or modified. The quick connect fittings are a source of air intrusion and should be replaced with clamps. Air in the fuel can be removed by using a preporator such as FASS or Airdog.

"Regulated Return mods"
The dead end fuel rails can be eliminated and the fuel rails can be re-plumbed with or without replacement of the AE injector with an AD injector.

I have done all of these modifications (except the preporator) and more and have a very smooth running engine with excellent power and no deterioration of the mileage. Do I KNOW that the modifications were of benefit? NO but I believe they were. My truck did not cackle much but it did have a mild knock at idle and there were times when air was a problem during the evolution of my mods. I accidentally created turbulent flow which released HUGE amounts of air and I heard the effects of air on the engine noise. The cackle was LOUD. Video of the source of my air.

If I were you and I was planning to keep the truck for a long time, I would be preemptive and fix the sources of air intrusion and/or put in a preporator and replumb the fuel system. You are out of warranty so that need not hold you back. You might be surprised at how much it changes the performance and sound of your truck."

 

[CooterBrown]

Thank You Sir

 

[southmike]

^^ ....lol

good info, thanks for typing all that.

 

[badford350]

lots of great info on that, thank you. Just one question. after a guy goes through and upgrades his fuel system to the regulated return and the famous hutch mode, would it benfit to change out the long lead #8 to same as the rest? or does it not make much of a diffrence?

 

[DarkShadowDiesel]

musta been a crack heyid, got hold o da wrawng stuff.

thanks for the info :ford:

 

[Haul_n_horses2]

lots of great info on that, thank you. Just one question. after a guy goes through and upgrades his fuel system to the regulated return and the famous hutch mode, would it benfit to change out the long lead #8 to same as the rest? or does it not make much of a diffrence?

It depends on what you want to do in the future. If you are going to stick with the OEM sticks, I would consider putting new o-rings in all of them and replacing the #8 AE to an AD if you have it. Or if new injectors are in your plans in the not distant future, then consider waiting.

 

[hotwheels]

You're learning more and more all the time there gregy. Kee up the good work!

 

[Cmonster]

Gregrob,
This needs a sticky.

 

[roosterdiesel]

Here is a little summary I posted a few months ago on the drama stop. Even Dennis said he couldn't do it any better.
"Sorry for such a long post but as some of this information is no longer accessible and having lived through the problem, I will recapitulate some of it's history for the benefit of those who are new to the 7.3L PSD SuperDuty truck.

One of the big problems with these vehicles is the design of the fuel system. The tank and it's associated plumbing were a common part between the gasser and the diesel engines. Gassers have to meet an emission standard based on the release of hydrocarbons into the atmosphere from the fuel system, not just the tailpipe emissions. So Ford designed a system with the infamous quick connect fittings that were easy to assemble and met the emissions standards so no HC leaks from the fittings. What they did not recognize was that these designs were disastrous for diesel engine as the air sucked in on the vacuum side of the fuel pump (either due to worn/stiff parts of the fuel pickup or leaky quick connect fittings) could exceed the ability of the fuel filter air separator and send foamy diesel to the cylinder heads where it's only route of escape was through the injectors. These problems were documented by TDS member Hutchinaugusta and he has fortunately continued to maintain many excellent photoessays here. This led to premature injector failure/wear and poor performance.

"TexasTowncar" (may he rest in peace) had outstanding studies looking at the problem and found that the cylinder pressure curve on the #8 cylinder was different from the others due in part to the sequential firing of the #6 and #8 injector. #6 stole fuel from the fill cycle of the #8 injector which was further down the dead end fuel rail. Another problem with the sequential firing of these two injectors is the effect of having split-shot injectors alternately sucking fuel and spilling it back into the fuel rail such that the agitation of the fuel results in release of air from the fuel due to turbulence. Ford/Navistar's answer to this problem was to change the #8 injector so it had a bigger pre-shot of fuel, the so-called long lead or AE injector. On early SuperDuty trucks with severe cackle the #8 AD injector was changed out to the AE (with modest improvement). Later trucks came from Ford with the AE installed. Despite these efforts, many 'Strokers found that their mileage suffered and they had unusually loud engines with cackle particularly audible in the 1400-1800 rpm range.

Several school bus mechanics and others with knowledge of previous IH fuel systems also recognized the problems with the plumbing of the cylinder heads. These had in previous IH implementations been fueled from the back of the head with fuel flowing rising forward and returning to the tank. This allowed air to pass through the fuel rail back to the tank rather than through the injectors. By replumbing the fuel system and eliminating the dead end fuel rails, TexasTowncar demonstrated that the cylinder pressure curve in #8 cylinder was more like the other cylinders and then in an experimental trial he worked with some hot shot truckers and a fleet of F350s modifying some and leaving some unmodified. The unmodified trucks had progressive loss of mileage over many miles where the modified trucks maintained their original mileage. With the unfortunate demise of TT, this data is no longer on the internet and as new iterations of the PowerStroke diesel have emerged this historical information is being lost.

So what is known:
1. Air in the fuel is bad for the pump and for the injectors.
2. Dead end fuel rails are a poor design to handle any air that should intrude into the fuel.
3. With dead end fuel rails and sequential firing of #6 and #8, the #8 injector is relatively starved for fuel leading to abnormal cylinder pressures with attendant damage to that injector and the rotating parts in that cylinder.

What can you do to eliminate the air in fuel issues?

"Pre-pump mods"
The fuel pickup is designed to recirculate any returned air if the temperature of the fuel is low. The duckbill flapper valve that sends the fuel/air mixture back into the tank can become stiff and remain open to allow air to be sucked up into the fuel pickup when the tank is low. This can be fixed or modified. The quick connect fittings are a source of air intrusion and should be replaced with clamps. Air in the fuel can be removed by using a preporator such as FASS or Airdog.

"Regulated Return mods"
The dead end fuel rails can be eliminated and the fuel rails can be re-plumbed with or without replacement of the AE injector with an AD injector.

I have done all of these modifications (except the preporator) and more and have a very smooth running engine with excellent power and no deterioration of the mileage. Do I KNOW that the modifications were of benefit? NO but I believe they were. My truck did not cackle much but it did have a mild knock at idle and there were times when air was a problem during the evolution of my mods. I accidentally created turbulent flow which released HUGE amounts of air and I heard the effects of air on the engine noise. The cackle was LOUD. Video of the source of my air.

If I were you and I was planning to keep the truck for a long time, I would be preemptive and fix the sources of air intrusion and/or put in a preporator and replumb the fuel system. You are out of warranty so that need not hold you back. You might be surprised at how much it changes the performance and sound of your truck."

Thank You Sir

X2


Budro....how much did you spend on that one guys Hutch mods last weekend?:swordfight:

 

[glamis_dave]

in regards to bad350 question dosent all 99-03 thucks already have ad injectors??? and what is the harm in doing the system but not the injector...will that hole now be more fuel where it was less fuel,makeing the same in ballence...............also this stuff is sooooo good..comprensive with good coverage,real teaching and info, without all the side talk and hyjacking,wanted to do it ,but never felt confident to try cause all the past info was in complete and vague...keep it up and us small fish may grow big yet....