Fuel from tanks not getting to the fuel pump

[6 Nebraska IDIs]

I've got a guy that wants to buy one of my trucks and ive been going through the inspection on it before selling it. it was such a good runner when i put it down a few years ago i didnt think much of it. However it doesn't start now. Im getting 0 fuel pressure. I replaced the pump and sure the truck runs for a few seconds when i refil the filter but only until it sucks it dry. so even with the new pump its still not getting fuel. im sorta at a loss here. Please help!

 

[trapper]

bad lift pump?

 

[icanfixall]

So you are teling us no fuel from the tanks reaches the filter... That can be lots of issues. A hole in the tank to filter suction line... Or a way too low level in a tank with the fuel suction head broken off. The problem usually will leave around 1/4 tank of fuel that wont draw out of the tank. A pluged fuel line from alge or dirt from sitting. A bad fuel tank switching valve. Sometimes they stick between tanks and nothing will flow thru them... Hope this gives you some ideas Sean...

 

[papastruck]

Might try getting a can of diesel and splicing it into the line to see what's what, starting with a line from the can directly to the lift pump. Then you can at least tell if the lift pump is working. Then work your way back. If it sat for a few years who knows what's going on in the tank, but at least you can narrow things down before going through the trouble of dropping it.

 

[Dsl_Dog_Treat]

Sean, check the fuel lines at the senders and where the main supply line goes from plastic to steel. Seen em rust right there and cause all sorts of hell on startups. If ya got an elcheapo electric pump, tie it in at the filter head and check for flow there then hit each connecting point going backwards to the tanks. If there's a leak yer gonna get bubbles and minimal flow. Restrictions little to none.

 

[sle2115]

Might be a tank switching valve issue as well if it's still in tact. I say do what everyone else has stated, get fuel to the filter head, get it running, then move back. Do you have an inline filter anywhere? Clogged filter screen in a holley fuel pump? Electric or mechanical lift pump?

 

[6 Nebraska IDIs]

Hey Guys.
I guess I didn't explain very well. I had it running several times but it would only run on the fuel in the filter and then die. The return lines (which were literally replaced a couple weeks before I retired it) showed some leaks so I fixed that and then moved back to the no fuel pressure issue. I hooked up a vacuum gauge into the feed line of the fuel pump (after I had already replaced the first one) and tested it to see if it was pulling a vacuum and it was, over 10 inHg, pleanty. So then I moved back from there, I jumped back to the forward side of the tank selector valve to see if i was getting vacuum pulled there from the pump as well and I wasnt so I knew it had to be in between somewhere. Well I followed the lines and sure enough some jack ball before I got the truck bypassed the water separator and the hose he used was air compressor line. It had so many cracks in it that it was sucking air through those cracks. I replaced that and it fixed the fuel issue. Now I have another issue, the cooling system is not pressurizing and its overheating.

 

[icanfixall]

Wow.. Its a good thing you found that fuel issue. Never can trust what another person has done these days.. Now on to other issues I guess...