I have searched the forums until I am blind and I cannot find anything specific to the above or following...maybe it is my search terms or lack of comprehension....

So, to add to the above question in the earlier post, does the PCM or IDM control fuel pressure at all through the pump or is the fuel pump just putting out pressure, as much as it can, all the time?

By my placement of the fuel pressure sensor I am monitoring pressure post filter. I am assuming that this is pre fuel pressure regulator (fpr) as the fpr appears to be on the return side of the equation. Correct? Is the fuel pressure regulator strictly mechanical? I do not see any wires running to it.... If it is strictly mechanical then the only path for the fuel pressure to bleed off is back through the fuel pump. Is this correct? Unless the valve is malfunctioning...... Is the valve one-way only?

The reason I am asking is I am getting ready to put a post pump filter, 2 micron, in line and I am going to remove the factory filter and fuel filter check valve prior to doing the fuel bowl delete. This will eliminate one of the above possibilities posted by white buffalo and we can all learn something or at least I will.

@baddogkuzz thank you for your suggestion. I am not opposed to rebuilding the fpr, I just did not have time earlier in the week to order one or pick one up at the Ford place..

If submarine docker rebuilds his and/or my problem goes away with the fuel bowl delete then I think we may have found it.

Otherwise I may have to buy a fuel pump.

 

New 2 micron post fuel pump filter is installed. Filter in the fuel bowl and the fuel filter check valve have been deleted. No change...fuel pressure is still erratic as heck............

After seeing how this fuel filter check valve and the hollow post that it is contained in operate, I am glad that I did the post pump filter upgrade. The o-ring that is located on the bottom of the post that "seals" the unfiltered fuel from entering the orifice that then leads to the chamber that feeds the fuel lines to the injectors is a complete joke...I'll bet that during high demand and high pressure that unfiltered fuel seeps by that o-ring.....

Anyone disagree?

 

Yes, I see the same thing in both my 7.3L's. Here's a pic when I turn the key on engine off (KOEO).



and then 20 or so seconds later. Not sure if it falls off slower or quicker on a stock setup, but it pretty much goes to zero on the Driven Diesel regulated return.

 

I can post up a video if you need.....

 

Thank you for the reply and answering this question. No need for the video though unless you feel like doing it. How do you like the regulated return?

 

Cool, so hutch & harpoon mods completed as well as the post pump filter in preparation for the fuel bowl delete. What setup did you go with for the Hutch Mod? Pre-pump filter & water seperator?

Also, what regulated return system are you building or buying? Some come with a mechanical gauge that sits on the regulator. I like having the mechanical gauge as well as electric gauge in the cab. Why two? Well the mechanical gauge came with the kit and I like to keep an eye on the fuel press in the cab during the winter so I can get as much warning as possible if things start to gel up. In my experience, the mechanical gauge is more reliable. I've had to replace the sending unit once already for the elec gauge, and occasionally it will still start to bounce around. If I get out, pop the hood and disconnect & reconnect the electrical connection on the sensor/sending unit it will stop bouncing.

When installing the regulated return I gutted the check valve, seemed to be a restriction in the higher hp tunes. It's there to prevent operating without a filter, I don't think I need to worry about happening.

 

I installed the ITP (now strictly diesel) regulated return on my F-250 in 2007, and in the Excursion this past summer when doing injectors & the turbo. It's a great kit, comes with all necessary hardware & great instructions. I kept the fuel bowl since I live in South Dakota & wanted to retain the fuel bowl heater.

For me the setup works very well, especially during the below zero temps in winter. It returns more warm fuel back to the tank than the stock setup did. In addition, it replaces the restrictive check valves in the head as well as the stock fuel line on the passenger side that tends to develop a crack at the mounting tab.

I'd do it again in a heartbeat -

(check valve)

 

P0476 & P0475 as you know are exhaust press control valve. Could easily be fixed from cleaning & removing any build up.

P0605 - clear it and see if it returns

P1668 - inj drive module

quieter(cackle) is what most experience. Did you make sure the fuel line from the tank is good and tight to keep the air out like Tugly mentioned?

I found the same when I did the Excursion

Well, you are doing everything in the right order in preparation for the fuel bowl delete regulated return and injectors. As far as the fuel pressure regulator goes, it is mechanical and is between the bowl & tank return line. That is the kit Ed suggested in his post above to repair/replace a faulty stock system. Here is a couple of pics of the fuel bowl connections............

 

One more post from an over-caffeinated buffalo:

Check that passenger side fuel line along the head while u got the valley cleared. That one has a tendency to crack at the mounting tab. You will probably replace this line when you do the regulated return but this is a common trouble spot on higher mileage 7.3L's.

 

I went with Strictly Diesel for all of the above. I checked around and by the time I drove around for most of the parts, and ordered the ones I could not get online, paid shipping and taxes, the savings would have been minimal by building it myself.

I will install the mechanical gauge also so that I have two points of reference just as you did. Thank you for that info.

I have been thinking it over about replacing the fuel pump. If you purchase the stand alone pump it is less than $130 which is 1/10th to 1/20th the cost of injectors. Seems like going ahead and replacing it is a sound decision. The old one is 17 years old, late 97 build date, and has 200k on it. Everything I read on here in ref to injectors and fuel pressure talks about how important fuel pressure is for the 7.3. What do you think?

 

Wow! Those are great pictures. Thank you. Yes sir! I went clamp crazy... a minimum of two, one on each side of the quick disconnect rib, with an additional one if it would fit. Thank you Tugly!

The codes come and go with no particular rhyme or reason with the exception of the ebcv. I do not know how to clean it but am going to wire it/disable it when I replace the injectors.

I have checked all of the lines and don't see any leaks. The valley is dry for once.....

 

Strictly Diesel and DI make some great kits, can't beat them IMO. That kit will replace everything from the fuel inlet to the heads. Since you did the Hutch Mod already the only stock pieces you will have left are the pump & fuel lines after the pump. It could very well be that your pump is the problem. We all Just wanted to make sure it wasn't something else before spending the $.

I agree - sounds like a good plan. I for one have a spare pump sitting on the shelf since one vehicle has 240K and the other 170K. I don't like being caught unprepared. Riffraff Diesel has great prices on this and many other parts, but check out Amazon.com for the Bosch pump as well. Some have snatched them up for less than $90.

Yes, fuel pressure, no air and no water are very, very important

 

Awesome! Thank you for the replies. I will not be able to work on it anymore for a few days. I am looking forward to it though....

 

Looking forward to hearing that you problem is gone!

 

Not sure if this was answered or not or even helps, but I have the stock fuel bowl with the isspro fuel gauge and when the fuel pump shuts off (aprox 20-30 seconds) it immediately goes to zero.