03 Yukon no start with 1/4 tank full

[Jack Davis]

I been having trouble with starting the Yukon when there is 1/4 tank of gas or less. It cranks but no start. I have checked fuel flow but nothing but I think I heard the pump running (can't remember). I add gas to the tank and it starts OK, I can run the tank down to empty with no problems but it will not start back up. I've been reading about the fuel pump and terminal connections. If it's the pump then why can I run it down to empty with no problem. If it's a relay then I have the same question, why does it not affect it when it has more gas in the tank? Could it be the check valve letting the fuel back in the tank as it sits? Then why does it not happen when it's 1/2 full?
[email protected]
Jack

 

[Sepiroth]

My thoughts are leaning to fuel pump. Others may chinme in here.

 

[02Lightning]

Do a fuel pressure check.

 

[scorpio]

I had the same problem, but sometimes even when i had more then half of tank it crank a long time before it turned over, changed the fuel pump all was good. hope this helps good luck

 

[boss13]

fuel sending unit! but it's attached to the fuel pump as one assembly.

 

[EliteTahoe]

May be the fuel check valve.
Got same problem. Never drive the car under 1/4 tank.
CAN do it yes, but dont stop engine. You will have to refill up to about 3/8tank before you start. Many gallons.

A tip is to not crank engine before you have primed pump 5 - 6 times before you crank engine. This will build up pressure and eventually push air out of system.

Always worked for me.

 

[bigsexy408]

most likely a fuel sender/pump issue

 

[metro273]

Definitely sounds like a bad sending unit on the fuel pump assembly?

 

[kandywhips504]

do you park on a slope? cus mine does the same tank when low of fuel when the truck leaning to the front, but starts fine with front is higher up than the back like parking on a steap driveway.

 

[z3ro]

I had the same issue. Turns out that since my z71 sits about 2 inches higher in the back (no idea why) it causes the gas to sit in the front of the tank.

Its gay but will be fixed when I lower the back.