Yes. 30 gph is standard.

 

Yea I'm easily flowing that. If I don't find any evidence of a leak I will pull my line at the pump and check for air there.

 

The reason for this thread is exactly why I chose to migrate the fuel pump from it's factory location to the end of the pickup in the tank. There is zero possibility of getting any air in the fuel if every connection is under pressure between the tank and the engine. There'a a reason deep well water pumps have the pump submerged at the bottom of the well.

 

If you're not getting air at the bowl, you're not going to find any by pulling the pump discharge. If there's no air then the # drops have to be caused by something else. Lots of things can cause these fuel # issues. The pump seems unlikely at this point,but wouldn't take it off the table just yet. I would probably attack this as systematically as possible to rule out sections and individual parts in stages to narrow down the location of the failure. Pull the feed line at the bowl, plug it off, I believe the threads match compression fittings but not sure. If they don't I do know the threads in the bowl are plain old pipe thread. Worst case you pull 1 and cap the end for hydro testing. If you pressure up the lines and they hold 90% of test pressure for 5-10 minutes I call them good and step to the bowl discharge and return. Plug them do they hold, and so on and so on. You may need to install a shut off on the suction side because the factory check valves rarely hold for long at all. It's a daunting and time consuming process but really the only way figure out where the problem is hiding.

 

Got my ball valve installed before
work today. Verified no air. Havnt gotten to start testing yet. But just to clarify I understand plugging the fuel inlet at the bowl and the return. After that will I need to leave the return plugged to keep it from bleeding back? I ask because I pressurized my system closed the ball valve and all of my pressure immediately bled off. Also i have read I can make my own sleeves with fuel line? Is this true? Not looking to leave them permanently but I only have 3 total parker sleeves and at 5 a pop at my local distributor I'd rather order some.

 

Get the Parker sleeves from Bob at Diesel O Rings.

Fuel pressure will normally bleed off almost instantly when the pump stops, no problem.

If the fuel filter gets dirty often you may need a biocide. This could explain why the problem returns after each section is fixed.

Can you get a pic of a glass jar of fuel? Or what is in the fuel bowl? Just so we can see what the fuel looks like.

 

Ok let me make sure I understand what you're saying. You've got a ball valve installed between the regulator and the fuel tank, and with the valve closed you immediately loose fuel pressure when pump is off? All that sound right? I see 2 things that raise flags here. First you're right you should hold some kind of pressure. Now that does hinge on the status of the check valve inside the pump, rarely do they hold 100% indefinitely but it should be a slow bleed at least. Second thing I'm questioning here is you had the pump running w/ the return closed off and didn't see pressure high enough to make you want to duck and cover(y'all remember that stuff?) for fear something was going to blow.

As for the Parker sleeves I've used vacuum hose as replacements and never noticed any difference. Of course I ditched the fuel bowl a few years ago after the second dealer purchased drain valve assy. started leaking and found multiple other leaks throughout the system. Ran a new ss feed and return lines and pieced together a RR setup.

 

I'll have to get a picture of the fuel in the am. This is the best I have for now I know my jug doesn't help much

I'd say it's cloudy for sure. Don't see any particulate in it. I left a jar out a while back in a Mason jar and it has since turned dark brown and sealed itself really well. I have some biocide I was thinking about getting an inline fuel filter and hooking my hold pump it and some fuel line and circulating it to clean the fuel in my tank. I'll have to run it down to pressure wash the tank. There is a picture above of how my fuel bowl looked a few months back. I cleaned it and have kept it clean since, I'd say I'm in it atleast every 500 miles or so and a new dark ring has returned at the bottom of the threads. I've been debating piecing together a bowl delete and regulated return kit.

As for the ball valve I misunderstood and put it between the pump and the tank. I cut out a peice of my retun line and installed a rubber hose so I could use a hose pincher to check my fuel pressure regulator. I havnt plugged the return completely yet. After clamping on my viscrips I slowly tightened then till I reached about 68 psi. Took the truck for a ride and still have the same pressure drop. I've thought about cranking the pressure until the leak becomes more apparent, but the thought makes me nervous I've already showered my entire engine bay with diesel thanks to a el cheapo fuel filter.

 

And your are right about me going through alot of fuel filters . This was from when i forst bought the truck and did the hutch mod





then i went through a few inline filters


bought a new fuel pump then noticed the same gunk in my fuel bowl


Then when starting at square one. I found my tank had a nice coating and I'm sure my new pump and fuel lines do aswell
when I do upgrade my fuel system if that is indeed algae I would like to have it undercontrol before hand

 

Well the weather has not been cooperating this week seems like it wants to rain when I'm not at work. Hopefully it clears up soon and I'll get outside and see what I come up with I looked briefly when I got off last night and sadly the valley looked dry. Hopefully I can find something I would really like to put those fuel system behind me

 

Banjo bolts?

 

I filled up the other day and put some diesel clear in. Hoping to clean out whatever that Is in my tank.I'm thinking of getting a clear inline filter putting it post pump then hooking into my return so I can circulate my fuel and see what is coming out of my pump. I have another brand new bosch pump but don't want to put it on till my tank gets cleaner

After removing my "leak detectors" I found that my hpop fittings are slightly leaking. I think my rear passenger fuel line could be the source of my leak. I'm not sure if it was wet fluid that was dried by my down pipe or if the blue shop towel just got a little warm. Will attach better and check frequently. I also learned my up pipes have started leaking had some suit on my towel so looks like that will be another project in the near future. I also noticed today that my fuel pressure is also dropping in park and neutral when I rev the engine quickly. It will hold steady if I slowly let it climb. .

Either way looks like I'll be finishing up my topside creeper this week so i can get comfortable incase that fuel line needs a new sleeve.

 

Out of curiosity, have done any testing of the electrical components in the fuel system. Not really sure why but your description of pressure dropping just blipping the throttle in park made me think electrical. I'm not any kind of expert in electrical but have learned these trucks can get pretty particular about their power. Voltage drop testing is the way to go on classics line these. With the years and miles they've seen the wires can start playing tricks on you. You can read 12v+ at the pump but as soon as it gets a load on the circuit it falls flat on it's face. IDK it's late so maybe I'm crazy but it was a thought.

 

You know I've been thinking the same. I get a little drop when I crank the truck with glow plugs running pcm is reading 13.95-14 once I get moving. Last night I had forscan running when I put it in neutral to tap the gas. I noticed my rpm showed 3800 in my csv when I did this. Not sure what would cause that faulty reading my cps is in good shape but like you said my wiring is getting pretty old. I'll rig up some alligator clamps today so I can get a reading

 

Looks like 14 at idles 14.1-.2 when I lay into it atleast on the power side I didn't check my ground. Will do next trip put