Like I stated in your other thread I think youre sucking air somewhere. Get a 12V electric pump. Cut your line back by tank. Hook it up inline, if you have a split somewhere it will show up shortly. Could be coppers or banjo seals too. Leave pump, makes bleeding system alot easier. Whats the line coming off your filter bleeder? Put the 6mm brass back in and snug it up. Be a great place to be sucking air. Good luck.

 

Like Red said, you're either sucking air or you've got a restriction in the fuel area. Blocked tank vent, blocked pickup, or collapsed rubber fuel hose. Not likely you go 2 defective fuel pumps.

 

that's just my fuel pressure test hose and gauge tapped into the bleed port. this whole thing has been a compound of things. because I found out the fuel solenoid was losing voltage during cranking so I pulled the plunger out. my old lift pump had a crack in the diaphragm so I got a new one. And now I believe I am pulling air into the system somehow. I was just trying to get a consensus on the precision pump since everyone mentions Delphi. I will try the electric fuel pump. do you have any suggestions on any brand?

 

I will try my clear tubing first and see what I get. if its from the tank then I will drop it. while im in there I will take that damn sock off everyone talks about. I had put the new tank and pickup in 100 miles ago before even reading about the restriction that sock has on diesel.

 

Eliminate the tank and lines completely (temporarily) by running a line from a fuel can directly to the lift pump. Then you will know if the problem is in the tank.

 

Sorry - what is the vehicle you are working on? One thing I did, and think everyone should consider, is getting a plastic or aluminum tank if possible. I had an aluminum fuel cell made and it takes away a lot mystery with fuel system.

 

My money is on the sock.

 

If it still has the sock on the fuel pickup, I bet that's your restriction. Those things are not designed for diesel fuel. Most diesel tanks will just have a metal screen strainer at best to keep large debris out of the lift pump. The fuel filter takes care of the rest. Also, if the sock is causing a restriction, the lift pump is creating vacuum that will find any air leaks in the fittings. Can be a compound issue.

 

what char said above, I had a case tractor that had a large piece of rubber trash that somehow got dropped in the tank, it would occasionally float on top of the pickup and cause the same issue you described

Btw I'm 45 mins north of you

 

It's a brand new oem CJ tank and pickup assembly that doesn't even have 100 miles on it. I did test my fuel problem with a Jerry can before and that's how I found out my lift pump was bad and problems with the fuel solenoid. But after fixing those issues I haven't ran from one again. I will fill the filter, run the jeep from a jug again and then see if it dies after 5 minutes. If it doesn't I will shut it down and measure the fluid in the filter. If hasn't went down then it looks like I will be pulling the tank. But I'd rather do that than pay for an IP rebuild lol.

Ky-donzi I drive through there about twice a month.

 

Mine is pulling air somewhere also. Did you find your issue?

 

Ok. So I have narrowed my fuel problem down. Recently my lift pump went bad and would not even prime. I went and bought me a "precision" brand fuel pump from O'reilly auto parts. They did not stock the Delphi and couldn't order it at the time. Installed it and felt a huge difference in the priming. Filled up my fuel filter, primed the engine and fired right up. 5 minutes later it died. Took the fuel filter off and it was almost empty. So I'm thinking it ran off the fuel inside the filter until it got below the pickup tube. Repeated this process and same thing. So thought I may have got a bad pump I so exchanged it for a new one and this felt even stronger. Repeated the process and same result. It takes about 9 ounces of diesel to fill the filter up and when it dies there is about 4 ounces left. When the engine is running I get about 6 psi on my fuel test gauge just past the filter. I will hook up some clear tubing this weekend to see if I'm picking up a lot of air and no fuel and that's why the psi stays at 6 maybe? When it dies, then the Psi rises to about 9 and then falls to 0.

I have attached a picture of the type of filter, the lift pump, and a before and after photo of the amount of fuel used. I also added a link to the video of my engine running while looking at the test gauge and then the engine dying.

Hose clamps such as the one in the photo on your lift pump are a good source of air leaks being drawn into the system. The area under the screw is not the same radius as the tubing, especially when they are as oversize as yours appears. Get rid of the cheap parts store clamps and replace them with band style or consistent tension versions.