how has your truck ran since you did this mod?

 

Flawless. I used to get the P2290, low injection pressure (not good at all) on WOT and I did the BB regulator spring mod, and the banjo bolt mod at the same time and WOW, ~62 psi at idle and about an 8 psi gain at WOT over what I used to see, have not had a P2290 code since.

Derek

 

hmm this is very tempting, how long have you had this on your truck?

 

FWIW: That code relates to the HPO system, not fuel.

 

anyone done this mod besides derek?

 

I just read the 4 pages of stuff you have at the .org not one test was done to varify any part of your claim about injectors 7 and 8 being starverd for fuel as your ebay auction states. not one test listed involving a gauge hooked up to measure change. You have assumed that the check valve is really a regulator its really not at all, the fuel return regulator is in the filter bowl and that is the only one on a stock configured truck.
To post an untested mod for a part that you dont understand its function and suggest people follow you is just bad advise. weather the mod is a good or bad idea... imo if its untested and you dont know what it even is a no sudden ill effects come about you are lucky.
Im very sorry if you dont like my opinion's but fact is I do know what they do. And you ebay add is half about injector damage.
well would you like the awnser as to what the check valve really does?

 

Is it really 30.00 for 2 banjo bolts? I cant see spending that much money for 2 banjo bolts that cost 3.99 at my local advance auto.

 

I read about this about a week ago and decided to pull my banjo bolts and take a look. I took the guts out of the stock banjo bolts and drilled them out myself. It took me about 2 hours, the driver side was a PITA to remove. I definately noticed an improvement in pedal response. And after researching some after market parts I can not see any difference to changing the banjo bolts compared to switching out with one of the aftermarket stage 1 or 2 kits that replace the stock banjo bolt with a 90* elbow with no valves inhibiting the flow of fuel. I am no ford tech and respect everything they have to say, but if you are willing to spend $300 for a stage 1 or 2 fuel kit than I cannot see the difference from changing your banjo bolts to a better flowing bolt. However I can see how this mod would allow more fuel pressure than what is recomended to the fuel injectors, especially if you have the GDS fuel spring. On that note I have the GDS fuel spring and my truck is running better than it ever has.

My step daughter Zoe recommended I put this in

 

the banjo bolt has nothing to do with regulating fuel thats why the holes are there.the issue is what does the valve in the bolt really do and whats it really there for. Also just for though how can we really test the outcome of the mod and how well it performs and under what conditions?

 

and as long as were on the whole fuel system mods what about looping the return ports together? what do we think about that?

 

The stock banjo bolt holes may be small enough to impede optimum fuel flow to the injectors, again not definate on this. But I agree that the guts or valve within is definately restrictive. Some have said that the valve is designed to keep the head pressurized but after inspecting the valve within I would disagree because the way it is designed allows fuel to flow back through. In my opinion the valves were probably designed to ensure that fuel pressure is equalized between both heads.

I am assuming you mean by a crossover line coming out of the port on the back of the heads. I think that would be a good way to equalize the pressure especially if one were to drill out the banjo bolts themselves like I did. I am a do it yourselfer and am working on making a crossover line and plan on having a port in the line that I can install a fuel pressure guage into. I think that this would give me the most accurate reading of the pressure that is making it to the injectors.

I have no idea how these after market companies can charge so much for simple designs that one could do themselves. I would rather spend $100 on a tool and $50 on material to do it myself than $300-$400 for a kit, such as the stage 1,2 or 3 fuel systems. I'll leave the R and D to them and build my own off their pictures and design.

 

I don't want to sound like I know everything because that is far from the case, but as a Mech.Eng I understand the flow characteristics of the bolt, the restriction in the lines, and the regulating system in the secondary filter bowl. I don't think I said the check valve was a regulator? It is stated in the 6.0L engine doc that

"There is a check valve in the front of each cylinder head that does not allow fuel to return to the fuel supply system. This type of system is called a dead-end fuel system".

That is directly out of page 27. But it can be seen that the check valve itself has a hole in it. How does this prevent backflow? It doesn't, and when there is ~60 psi of positive pressure in the secondary fuel bowl (where it is regulated via the poppet spring) and the injectors are using fuel (vacuum) then it is pretty hard to convince anyone that the check valve is preventing backflow. It's preventing fuel flow. Pressure is a function of a fluid force over area and the 2 small holes in the banjo bolt have a smaller combined cross sectional area then the fuel lines themselves therefore, you can deduce that the greatest pressure is being created at the banjo bolt junction.

All I am saying is, the pressure is being built up AT the banjo bolt, the poppet spring in the secondary fuel bowl is going to open because of the pressure created at the banjo bolt. So on a stock vehicle there is no way to really know the pressure inside the head after it is restricted at the banjo bolt, if it is reading ~60psi at the fuel pressure test port on the secondary fuel bowl that is quite insignificant in the actual pressure inside the head. It's a shame I know but with the bigger banjo bolt then the lines become the restricting factor and you can at least know that the pressure is being built inside the head and not at the orifice of the banjo bolt.

Is this making sense guys? I'm trying my best to explain it. The injector starvation has been talked about many times before in various post so I will leave that browsing to the reader. These bolts were put out there for people that understand the problem in the stock design. I am not trying to make believers or anything, just stated my findings. I have been on here since 2004 but I prefer to read and educate myself 99% of the time. Watch, listen, learn... make an educated decision.

Derek

 

I sent this question off to ford

Hotline Assistance Request:
im looking for information on the fuel system check valves. there was someting stated about them sometime ago in a tsb dont remeber the number sorry. I belive the tsb has been deleted. what I am after is basic information of what it does and what concerns can be caused by a failed checkvalve in the fuel system. and any diag to isolate that concern. thank you.

faulty Fuel Check Valve (banjo bolt at the front of the cylinder head) may cause erratic misfires, surging, running rough, etc. In truth, actual failures of these fuel check valves are rare.
There have, however, been reports of faulty High Pressure (oil, not fuel) Check Valves that cause drivability concerns. Like a possible fuel check valve concern, a high pressure oil check valve will often produce similar symptoms (slight misfire/surge/running rough).


Recommended Procedure:

Verify the operation of the bank 2 check valve by disconnecting all bank 1 fuel injectors.

With the bank 1 fuel injectors disconnected, use the scan tool to monitor cylinder contribution using the Power Balance Test. Refer to the Power Balance Test in this section.

The cylinders with the fuel injectors connected should be contributing evenly.

Erratic contribution from the connected fuel injectors indicates the check valve on that bank is not seating correctly.

Connect the bank 1 fuel injectors.

Disconnect the bank 2 injectors and repeat the procedure to verify the operation of the bank 1 check valve.

so basickly they will produce the same type of concern as the oil rail stand pipe and can be tested in the same exact manner.
they are there to stop fuel pulse issues from the changing fuel pressure when the injectors discharge. this helps even out fuel pressure to each injector in the head. it should also reduce the change of lack of fuel pressure to an injector caused by a large pluse elsewere in the system.

also to test fuel pressure in the rail after the banjo bolt can be done at the back of the cyclinder head. using the simulated fuel load mode test tools.

and a big thanks to the Op for shareing his views in both an intelligent and educated manner.

 

Just over a month now. There are others on here and PS.org that have bought the upgraded banjo bolts, hoping they will chime in with their experience soon enough.

hubler13f stated above "I definitely noticed an improvement in pedal response.", he also stated he used the GDS fuel spring, which is similar to the BB mod I performed at the same time as well.

Derek

 

More discussion?