B7500 fuel starvation

[North Idaho Wolfman]

Get a piece of clear hose and run it from the tank down to the filter from the filter to the pump from the pump to the injection pump from the injection pump to the tank.

Start and run it and look where the bubbles are coming from!

 

[drewzee87t]

Update:

I decided since there had been grass clogging up the filter shutoff before, that there was potentially more where that came from. I decided to clean out the tank as best as possible and also to rule out bad fuel while at it. Here's what I did:

Emptied tank into old 2 gal gas can (I emptied it out first) getting about 1.5 gallons. When I opened the main fuel line to the filter it was barely dribbling, so I blew compressed air in to get it flowing. I got some stuff coming out and it re-clogged numerous times before the tank was fully empty. I took another 2 gal tank and put it under there with a funnel to empty the tank into and put a funnel with a screen filter into the gas tank fill neck. I dumped the 1.5 gallons back into the fuel tank and got quite a bit of grass clippings in the screen.

Again blew in compressed air and got more and more and more crap out of it. I did this whole flushing and blowing and drain and refill about twenty times until I could not detect any more junk coming out and the fuel line was dumping the entire contents with no indication of any blockage.

Then I removed the filter, unclogged the stop valve, cleaned the filter element and replaced.

Then I used a shop vac and ran it around as best I could in there for a while.

Then I got NEW fuel from the store and put in 2 gallons, and now she runs again. I haven't tried loading her but it runs good now. I would estimate I pulled a cup or more of grass clippings, bugs and even several small grasshoppers out of the tank. I am expecting I will be doing this again, but hopefully I got the majority of it.

Unfortunately either the compressed air or the vacuum did a number on my fuel sending unit, so my gauge is no longer working. I am not sure if I might have jammed it down when running the vacuum. It's reading super duper empty.

I still have a problem with the fuel return line from the IP that goes directly to the tank. I have put a NEW line on it and also blew it out to make sure it's not restricted at the tank. When I hook up that hose, the fuel level drops in the bowl and the tractor dies. If I keep that hose blocked off she runs great.

Any more suggestions? I didn't have access to any clear line that would fit either hose, I may be able to get some at hardware tomorrow, but I am not sure that putting that line on my returns and such would do anything other than indicate that I have leaks from using the wrong line or the connections not right.

Thanks for the help again! I think I am almost there, just need to figure out this return issue.

 

[drewzee87t]

I think I got it solved.

There were two versions of fuel tank on this tractor, one has three returns (early version) - which I have. The later version has only two returns.

The other day I asked if there was a check valve on the return that I deleted and was told NO. There must have been, or else a tube on that return from the fuel filter that would go to the bottom of the tank inside (or a check valve inside the fuel tank).

I don't know why this particular item failed on me, but it has and possible from blowing air into the tank to try to clear obstruction. There would be a reason why they re-designed the tank. I have plumbed my tank so that it works just like the re-designed one.

Picture one is old tank and piping design. Picture two is new tank and piping design. Pictures three and four is how I plumbed it.

I did manage to find some clear tube and a tee in one of my junk boxes in the shop. I am not getting any bubbles. I suspect that the either the in tank check valve failed, or the tube inside to the bottom of the tank failed/disintegrated which is why the tractor won't run correctly on less than half tank. I also had a really dirty tank and fuel setup that made this a lot harder to troubleshoot.

If this is not the final fix on this problem, then I know for certain the fuel pump cam is worn and I will just get an electric lift pump and stick in inline.

What a troubleshooting path this one was. Thanks again for all your help. Hopefully someone gets some help if they end up finding this in a search.