timberjack 360 skidder wont run

[timberjack97]

i  need  some advice   my timberjack 360  wont run after it gets down to half a tank of fuel in it  I tried everything I drained the tank changed my  lift pump but news fuel filters on new fuel line  I cant seem to find the problem any ideas?

[Bill_G]

You may have some debris in the tank outlet .

[coxy]

does it have a split tank with a cross over line if so the line my be cloged it happens to my cat  all the time  good luck

[timberjack97]

yes  it  does it has a cross over line the tank is on both sides 

[coxy]

ya whene my line gets cloged it only drains one side of the tank it was a pain in the but till i figerd that one out  let us know what it is whene u figer it out 

[timberjack97]

I blew through it by hand and could see bubles like the fuel was moving  do you thi should try blowing through the line  with an air compresser?

[coxy]

try it u have nothing to loose  hope u get it  let us know

[timberjack97]

does anybody  think it could be my injection pump going  bad?

[giant splinter]

It's not likely that its the pump, the air in the crossover line is the biggest indication that some air is entering the fuel system. I suggest you chase out the fuel lines and fittings for possible leaks and check the fuel lift pump on the output side to see if its pumping strong by isolating it.
It does not take a lot of air for the fuel system to fail on delivering fuel, once a small amount of air winds up in the right place like a bubble in the line the pump can do nothing but compress the air bubble and the fuel will no longer get beyond that point. I fixed one like this by adding a small Bendix electric fuel pump and a short fuel line in a bypass around the existing fuel system, then when the job finished up I was able to take enough time to fix it correctly. Turned out to be a line clamp on the suction side of the system that had been overtightened causing a small crack and was letting in a minute amount of air intermittently and causing the interruption in fuel flow. I have carried the Bendix electric fuel pump around in my tool box for years and have had only needed it a few times, I know if i leave it in the shop something will crap out in the field.

[timberjack97]

I put a new lift pump on also  do you think I should blow air the  main fuel line or blow it in the tank  with the compresser?

[giant splinter]

Blowing out the lines must be done carefully, the fuel lines that are before the injection pump are for the most part not high pressure lines and the flexible line cant take a lot of pressure. After the injector pump is a different story on most equipment they can stand high pressures, Detroit's are a little different in that regard.
Purging fuel lines after having problems that involve fuel delivery is always a good idea, try not to introduce high pressure into the lines and blow them out slowly till you see that air and fuel is moving freely.
I think you could blow out any line you can get to just to be sure there is nothing in the lines that does not belong in them.

[timberjack97]

its 6 bt  cummins   engine in the skidder   do  you have  a skidder to

[giant splinter]

I have a 518 Caterpillar and I am sure the fuel system is different than your Timberjack 360.
With yours having two tanks its best to isolate the tanks and the crossover transfer line from the secondary tank, then monitor the fuel flow into a 55 gal. barrel or some other clean tank, if the fuel flows strong at first and then slows way down or stops your tank vent may be plugged or if the vent is in the fuel cap the problem may be in the vented cap. You mentioned that after you fuel the tanks full the rig runs good for a few hours and then just stops running all together, this is pointing to a plugged vent or breather somewhere in the system as for my best guess. Find a service manual for the machine and go through the venting section to locate the location and service interval of the fuel system venting arrangement. I hope this leads you in the right direction and helps you solve the problem you are having.