I want to tell about my John Deere 7220 fuel line problem. I have been battling a fuel system problem on my tractor for far too long. The dealership seems coy on the problem as I suspect they have had several similar problems (hoses) but maybe not exactly this one. This is the problem… When I start the tractor, it starts very well, with no air in the system. I let it idle for several minutes, there is no air in the system. I start working with him, lately he has been feeding hay. At idle it moves the bullets without problems.
If I bring the RPM to 1500 to 1700 there is no problem initially. After a couple of minutes, however, it starts to malfunction and will continue to malfunction even if I reduce the idle again. The caution light comes on in the cab. Now if I turn the engine off at that point and turn it back on, thereby activating the fuel pump for a few minutes, the whole process starts over. Caution light goes off, idle is fine.
The steps I have already taken to fix this:
– replace ALL and I mean ALL braided fuel lines in the system (Braided lines – bad idea),
– put several fuel filters (primary and final),
– replaced ALL rubber gaskets and seals,
– replaced ALL crocodile clamps with worm clamps.
I have not replaced the fuel pump yet. I really think it is an air in line problem as I can loosen the supply line that goes to the injection pump from the filter while it is running and I get a little foam (little bubbles) coming out. If I let it run for a bit and then close the duct, it gets smoothed out again like I started the machine all over again. Then the process starts over. I’m looking for ideas of where the air source might be. The pump is the only thing that has not been replaced. Could it be in the pump, in the fuel filter housings? I do not know what to do with this. The caveat is that it doesn’t do this ALL the time, but it seems to be increasing.
Thanks for any suggestions.
I can think of two things:
- When you changed the fuel hoses, didn’t you accidentally remove the limiter? There is a small fitting that goes on a hose that would look like a butt joint, but it is not a joint, it restricts by-pass flow.
- Another thing is the electric fuel pump that is inside the frame. Depending on the serial number, you will probably need an upgrade kit. Different way of mounting the pump, also I think there was some change in the routing of the hose. I went through this problem with a 7320. The first time it was the electric pump, and then there was a bug that put a hole in a fuel line, and it happened to be the line with that limiter on it.
I put it back with just one hose, and it doesn’t work that way.