my little rubber piece has been broken for 30k miles. That being said I do not know if its important.

 

All put back together. Aired out the lines and still only 40 psi.
(Had dropped the tank because there was sand prefilter in the hfcm).

I am totally stumped. My next guess is that I did the blue spring update incorrectly and left some thing out when I put it back together. Anyone have pcictures on exactly what it is supposed to look like? I'll take it apart tomorrow.

recap: Low fuel pressure> replaced fuel pump, fuel filters, cleaned out hfcm, dropped tank, blew out lines and still 40 psi.

PS my theory on why there was sand in the hfcm but clean tank and lines is this: Its 2004 and John (previous owner) is living in South Beach. The economy is booming and he buys himself a loaded Diesel Excursion. He is married to a smoking hot latina who has a serious temper. Unfortunately for him he strays and gets busted cheating on her. Since she is a the beach she does the logical thing and pours sand in the tank without telling him. The fuel pressure goes to zero, kills the injectors and the dealership informs him that the consequences of infidelity aren't covered under his warranty.

Naturally he also finds himself in divorce court. This results him in turning the Excursion into Carmax in Ft Lauderdale for a nice cheap KIA. Carmax does the repairs but doesn't clean out the HFCM because the car is now working.

 

That's what I'd suspect. Not sure there are any pictures except the instructions that were included with the kit, but the brass plunger with "o-ring" goes in first followed by the spring and then the cover goes on. Sometimes the spring gets cockeyed on reinstall allowing the plunger to pop out and stay out which releases all your fuel to return. Have you verified your fuel pressure with a manual gauge? They are fairly cheap at an autoparts store.

 

Fuel Regulator Upgrade w/ Pictures - Diesel Forum - TheDieselStop.com

https://www.ford-trucks.com/forums/1...ue-spring.html

 

Ok new issue. Fuel pressure will be at 40 then it will slowly start to drop. till it gets low enough that I shut it off.

Seems like the fuel pump is running intermittently.

When the "key is on engine off" is the fuel pump supposed to run until proper pressure is reach and maintained?

#4 and #6 injector are having issues. Could bad injectors cause low fuel pressure?

When I put everything back together could I have done something to allow air into the lines?

 

IDK if say an injector gets stuck on/blows the tip off if it will cause low fuel pressure

I would have to say if low feul pressure was caused by an injector it would be hydrolocking on you or blowing seroius smoke out the tailpipe

More common woould be Low fuel pressure taking out Injectors due to the fact its side load Plunger Driven design

A cut/pinched or any damage to any filter housing oring would cause it to suck air in

I agree you need to check the fuel press regulator make shure it didnt get cocked

I assume you have codes for #4 #6 injector/cylinders what are the codes

Hope you get it figured out soon this has to be frustraighting

 

[quote=steventothemax;11301196].

Seems like the fuel pump is running intermittently.

When the "key is on engine off" is the fuel pump supposed to run until proper pressure is reach and maintained?quote]







The 6.0 has no Factory fuel pressure sensor so it doesnt shut the fuel pump off when proper fuel press is reached cuz it has No way to know it just times out and turns off untill truck is started


The fuel pump just runs a set amount of time when key is at KOEO IIRC 30 seconds or so then shuts off


Where did you tie in for your AM fuel press sensor sender hopfulley the fuel press test port at the upper fuel filter

 

OK that super helpful. Thanks. Tied it into test port.

 

It seemed like before the fuel pressure would start fairly high. Now it starts low and has to build. Could this be caused by an airleak from improperly putting the lines back, or a gasket that isn't sealed?

How about this procedure?:

First, pull fuse 302 (PCM) and relay 304 (FICM) and then pull the secondary (upper) fuel filter, remove any fuel, and then verify that it is being filled by cranking the engine. As it is being filled, make sure there are no air bubbles. If there are, you have a leak in some connections, the HFCM suction line, or the HFCM o-ring (most likely). Be sure to lube the o-ring w/ oil before re-installing.

 

Some suggestions.

Check the primary filter cap o-ring. If it's not sealed properly you can have fuel pressure issues and not leak (from what I've read). Check the standpipe in the secondary fuel filter. If it's broken it can cause fuel pressure or fuel starvation issues. Check your line connections to make sure they're snapped in correctly. As was previously suggested, get yourself a bucket of fuel to use for a supply and see if there is an issue with the pickup. Check the insides of the lines at all the connections. They are actually very small and you could have an obstruction that won't allow enough flow, especially if you suspect previous sabatoge. Suspect your new pump. Try a known good pump and see if you have the same issues. Take the fuel pressure regulator out of the equation and see if the pump will build enough pressure as a stand alone unit. Bubble test your injectors for a fuel leak.

 

Ok here are some updates:

A picture of the inside of the HFCM. To recap the tank has been dropped and the lines blown out, but there was no evidence of this sand anywhere else in the system. No sand post filter in the HFCM. I have ordered a seal kit for the HFCM since I am now getting strange new drops in fuel pressure and there was a drop of diesel fuel on the bottom of the HFCM.



I installed new injectors in #4 and #6 I'm getting conflicting opinions on if this could have contributed to low fuel pressure. We will see.

While I had it apart I took apart the fuel pressure regulator. I had installed a blue spring upgrade kit. I wondered if I had done something wrong. Was the plastic thing supposed to be black instead of white like this one? (fyi this is a blue spring. The blue has just worn off.)



Here is a picture of an injector with sludge on it. I changed the oil regularly but had a bad oil cooler until this summer.



I am going to trade out the new fuel pump for a newer one while I do the seal kit on the HFCM. Hopefully between that and the new injectors I will have good fuel pressure (and good mpg) before I leave for Florida next week. Any other suggestions??

Thanks

Steve

 

The carbon on the injector tip looks perfectly normal. It's not oil sludge as that's inside the combustion chamber. The white plastic piece in the regulator chamber looks fine. Never heard of any color difference. Doesn't leave much but a bad pump or an obstruction in a line somewhere.

 

Thanks. Should I blow out the line between the HFCM and the fuel bowl? Since I already have the fuel line disconnected? Does the fuel line from the HFCM go somewhere else first?

 

It goes from the HFCM to the fuel bowl--about 4 feet or so long. There are actually 2 there--one goes from the fuel bowl back to the HFCM and then back to the tank.

If you are confident that blowing out the fuel lines took care of any obstruction then that doesn't leave much but a bad pump. The only other thing I can suggest is that you are sucking air at one of the fuel line connections. You could try pressurizing them to see if you have a leak.

 

I only blew out the lines between the tank and the hfcm, not between the hfcm and the engine. There was no evidence in the hfcm that the sand had gotten past the filter so I didn't do this originally. I will now.

How can I check for pressure along the lines?