03 Yukon XL 2500 Fuel system problem

[quick60]

Hello everyone. I spend most of my time in the 67-72 forum since I own a 67 GMC. Im here seeking help for a friend with a fuel delivery problem in his 03 Yukon 2500 4x4 w 6.0L engine. He has had it in two different shops and neither could figure it out.

He has to leave the fuel cap cracked a little or it creates a full on vaccum in the tank and fuel system that the truck just completely shuts down. He can leave it tight and drive for about a quarter tank but then it starts to affect the performance of the truck. Then when he loosens the cap a tremendous rush of air goes into the tank for about five seconds. He has had to replace his his fuel pump twice in the fuel pump twice due to this problem.

To date he has replaced the fuel cap, 2 fuel pumps, fuel filter. He had some sort of fuel solenoid that was clogged with dirt but cleaning that did not help either.

He lives on a farm and drives a dirt road to get in and out of his property so not sure if that has anything to do with it.

Any help would be greatly appreciated.

[bighaas79]

If the vapor or vent lines, evap canister or, vent valve is plugged it can cause these problems. these era trucks were notorious for road dust collecting in the lines, canister, and valves. Gm issued relocation kits to try and eliminate these problems.

[quick60]

I will pass that along, thanks for the help.