No fuel pressure

[buono93]

Hi all,

Back in the fall, after my truck broke down with a little less than a quarter tank of diesel, I decided to do the electric fuel pump upgrade and replace the fuel lines with AN braided lines. First, I pulled the sender out of the tank to find the bottom section had fallen off. I hose clamped it back to the pick up and added 5 gallons of fuel to the tank. Since the previous owner removed the second tank, I ran the feed line from the tank directly to the inlet of the new electric pump mounted under the hood. I filled the lower section of the pump with fuel and ran a second line from the pump outlet to the fuel filter housing input. I also replaced the fuel return line from the 3 way junction where the return from both cylinder banks meet back to the tank. The new pump kicks on with the ignition, yet when I open the schrader valve at the fuel filter housing all I get is air, no fuel. Any ideas? Thanks!

 

[DrCharles]

That's a pretty simple fuel supply system. Tank, pickup, line, pump. One of those has to be the problem!

Either there's an obstruction in the fuel line somewhere, or your new pump is no good. What kind of pump did you install?

(It's possible to have a massive air leak too, but you'd see that leaking back when turned off. Also, could you by any chance have reversed the pickup and return lines at the sender? There's a one-way "flap" valve on the end of the return).

 

[buono93]

It’s a Carrier Transicold pump. I pulled the sender out of the tank and stuck the feed line directly in the fuel and still nothing. When I depress the schrader valve I do get a slight pressure release so the pump is working to some degree. Really at a loss here.

 

[hesutton]

You gotta start either front to back in the system and check each part. Are you getting fuel at the pump outlet? Have you tried isolating the pump from the system to make sure it is working? I'd get a jug of fuel and put a hose from it to the inlet of the pump and put a hose on the pump outlet into an empty jug and power it on. If it isn't moving fuel, your pump is a lemon. If it pumps fuel great (don't know the spec's of the pump you have, but it needs to meet those specs), you know you have an issue between the tank and the pump.

Heath