as I understand is at under hood filter and at WOT under load. If you will,please consider this. At test port or a billit filter cover with a tee allowing press guage and ball valve equiped with an orfice that would flow 500 to 800 MLiter per min @50psi ,engine off,key on,hose from ball valve to fuel can. Would this arrangement surffice to test fuel pressure? If this works,it would allow testing eventhough the truck is undriveable. Not to mention there are days I just don't feel like driving around the neighborhood at WOT. So those are my thoughts,what are yours?

 

You need to have the motor running to see what the pressure is under load. All you will be doing is checking the fuel pump output pressure.

 

If not the fuel pump,what generates pressure at the filter?

 

the fuel pump produce both system pressure and system vacuum.
You need to tap in to the upper filter housing for testing pressurs its the most accurate spot to do so. Not only do you need to be at wot but also high load. The reason is that high load and wot will require the most pressure and volume. If volume drops off then pressure should go down as well.
Just sitting in the truck with the tac at 4k and foot to the wood is not going to cut it for a fuel pressure test.

 

Da-bees

What a lot of people don't understand is that they can have adequate pressure without having adequate volume. On a pump like this the more you turn up the pressure the less volume you typically see. 65psi all day long isn't worth a hoot if you're only getting a cup of fuel to go with it. On the other hand you might get 50 psi and 5 gallons of fuel from the same pump and it will be more than adequate. That's the whole thing about testing UNDER LOAD. You can sit in the driveway and run 4K rpms and probably won't get one psi of boost, but put it in gear and go 1500 rpms and get 20 psi because it takes that much more work to get the job done.

 

Hey thanks for all your comments. Evidently I was too brief with my question. Good information to know about the conventional way of testing pressure,just as I noted in the OP. I didn't have the engine screaming @4k rpm. Frankly I would not see if the engine will do 4k in neutral but I would hope it is programed to prevent those #s in no load because they might break something. The Op says "engine off". The ball valve metered to a flow rate aproxamating fuel consumption driving 70mph towing 8k lbs serves to confirm the pump can maintiane pressure while delivering high flow rate. The hose from ball valve to fuel can is to prevent diesel baths. The fuel can is used along with stopwatch,one 1,000-two 1,000 or most likly the secound hand of a wrist watch to measure flow. The tee is in place to allow a pressure guage and a flow point(ball valve)to functiom at the same time for what I hope is obviouse reason. That is the long version of the OP. Now can you help me with your observations. Partsman,when you say "boost" what exactly is that and where should it be monitored? Cheezit when you say "vacuum" do you mean suction or does a vacuum play into the test also and where should it be read? I am fully aware that a method is in place to do this test,but I am just one always looking for better,easier,faster or maybe safer ways of doing things instead of parroting everthing I hear. On the other hand I normaly ask if some thing has been tryed so I don't waste my time,hope I am not wasting everyone elses. Thanks in advance for any and all observations.

 

ok so we all understand there are to sides to a pump any pump for that matter. there is a suction (vacuum side) and a discharge side (pressure)
The pump vacuum test is refered to as an inlet restriction test. this will test from the pump to the tank for a restriction. A reading that os more then 6" h2o is very bad. 6" is the max limit normal is 2"-0".
to do this test you would need to T a vacuum gauge in between the back of the pump and the line commoning into it. If you have a high reading then move the T to the tank at the outlet line. If the restriction is still present at the tank the problem is in the tank if its gone the issue would be with the supply line to the pump.
Hope you followed that if not let me know.

Now for what partsman is saying. the truck must be under load simulated or otherwise, drive at WOT and underload were boost is being generated. This will allow you to what the true working fuel pressure is. just doing it in your driveway with out some form of simulated load device (we have a special tool for that at the shop its a metered ball valve) is useless. If you cant simulate load you will need to drive it with the gauge hooked up.

 

Fellas,
Do you know where I can find a flow diagram or schematic for the fuel system of our truck? This would help in my understanding. I would like to see how the fuel gets from the tank....via filters & injectors..to combusted. Thanks

 

This would be the whole enchilada--it's in the tech folder: Powerstroke 6.0L Technical Intro Manual

http://www.backglass.org/duncan/ps60...l/ps60_028.jpg
http://www.backglass.org/duncan/ps60...l/ps60_030.jpg

 

Thanks! Thats perfect, thats exactly what I needed. Also, do you know if their is a detailed right up about where and how to install the fuel pressure gauge? I would like to have an example to go off of before installing mine. What type/brand gauge are most using? I would like to use an electronic one. Maybe this calls for a new thread....as I am becoming a little off topic.

 

The last link listed (pg. 30) shows the fuel pressure test port in the secondary fuel filter housing. That's where your fuel pressure reading would come from M12x1.5 straight thread w/ o-ring seal. ITP has a hose with a schrader valve to bleed the air off that you can screw an electrical sending unit in and then run wires to the cab for an electrical gauge. Works very well.

 

I have the ISSPRO EV2 gauge kit. I bought it from Diesel Manor. You will need the adapter fitting for the test port. They know what you need. My sending unit is installed directly into the adapter. I mounted my gauge in a single pod steering column mount, also from Diesel Manor. They have the color match paint too. $200 for it all

 

I cheated for my gauge install. Since I'm 2x4 I mounted mine just to the right of the steering column where the 4x4 switch would be. It's a perfect spot for a single gauge that you want to monitor closely. The rest of my gauges are above the mirror kinda outta site of prying eyes--lol.