M1009 will not run creates suction at the fuel filter

[dirtballgear]

I have a M1009 that has been my daily driver for three years.yesterday it started having problems. It has a new 31 gallon fuel tank, a 4 sprout sending unit, a new mechanical fuel pump with Aeroquip lines and a spin on fuel filter. Today it starts and idles fine but dies under throttle. It creates suction at the spin on fuel filter and when the petcock is unscrewed it sucks air in. When the inlet line to the fuel filter is unscrewed the pump works fine. When the outlet line from the fuel filter housing to the IP is unscrewed it pumps fine. If I prime the fuel filter and screw it on it will run fine until under throttle then it dies and if I unscrew the spin on fuel filter it then is only half full. I do not understand what is causing the suction or making it act like something is clogged. Help please.

 

[dmetalmiki]

That sounds like a filter problem. There is another post on here with much the same symptoms as your having. I think some of the advice there might be helpfull to you. Those 1009s seem to have problems in the winter. (waxing?)
http://www.steelsoldiers.com/showthread.php?135722-m1009-quit-on-me

 

[rsh4364]

If the pump works fine with outlet line unhooked I would think all is good to that point,maybe check valve on return sticking? Really interesting problem.Hope someone with experience comments.Last summer my 1009 did something similar,I opened my fuel cap,whoosh ,sucked air into tank,then truck fired right up? I no longer tighten my fuel cap.

 

[richingalveston]

I have had new fuel pumps fail quickly. They pump fluid fine on an open circuit but will not push fluid with any back pressure. Remove the line going to the IP. turn the truck over with your finger over the hose. The pump should put enough pressure that it will spray fluid when restricted by your finger. IF you do not feel pressure at the end of the line then the pump is bad. when they go bad they can actually pump back to the fuel cell causing the vacuum you are experiencing.

Otherwise it sounds like the IP has gone south, The IP can produce the same Idle only situation when it decides to quit.