B7800 won't run and has no power

[iamhistory]

Ok fellas......I need a hand if you wouldn't mind.

I have a 4 year old B7800 with 348 hours on it. It has been a great machine and I have taken care of it. It has suddenly developed a problem where it will start and run like normal and after about ten minutes it starts to conk out. It will barely idle, has no power, sometimes shuts off, etc. and continues to do that until I let it sit for a significant period of time.

I installed a new air cleaner and new fuel filter. I checked the lines for blockages and didn't find any that were apparent. I drained the tank to try and get a look for debris. I couldn't see anything. I blew out the fuel line going into the tank and I blew out the air dam in case it was blocked...it wasn't. It does the same thing with the fuel cap on tight, loose or off. The tank doesn't appear to be collapsing. When I drained the tank the fuel flowed very well out of the line. I don't appear to have any leaks anywhere and my fuel is not old or dirty. One day it ran fine. The next it didn't. That quickly.

When this started I had a lot of white smoke. Now after several trouble shooting strategies, I don't seem to have the amount of smoke I had but I still have no power. I tried all the simple stuff and it has not worked. The thing that has me worried is the fact that it will start and run fine cold. Every time, after about 10 minutes, it starts shutting down. The idle revs slightly up and down and seems to not change even with the accelerator up high or low.

I have heard the fuel lines are heating up and collapsing to replace with reinforced lines, the tank has a vacuum problem and is collapsing (checked), the injector nozzles are bad but doubtful b/c of 348 hours, the fuel filter is dirty (now new) the air supply is cut off (new filter and checked), the lines are clogged (checked pretty well) and a few others I can't remember.

I have taken all these suggestions seriously and checked what I could. Nothing has worked. Something has to be heating up and then causing a problem. Do you guys have any suggestions?

Thanks for taking a look at my thread and thinking about this. I need my machine and my chores pretty much are screwed without it. This causes a big headache for me and I've been trying to get it fixed for over a week now.

 

[birddogger]

Maybe I can help. Maybe. Had this problem with one unit at the gun club. Do you have a see-through fuel filter bowl? if so does the bowl go half empty when this happens? We do and it did. The problem was stink-bugs! Yes stink-bugs got in the fuel tank and would settle over the fuel outlet and choke off the flow. That took a couple tries to siphon out the fuel, 1/2 inch hose, through a strainer to catch the bugs.

Apparently the bugs like skinny places and were hiding on the flat areas on the fuel filler neck. When the cap was removed to refuel I guess they got knocked into the tank. So if you have lots of stink-bugs in your area, I'd check that.

 

[clarksvilleal]

Maybe I can help. Maybe. Had this problem with one unit at the gun club. Do you have a see-through fuel filter bowl? if so does the bowl go half empty when this happens? We do and it did. The problem was stink-bugs! Yes stink-bugs got in the fuel tank and would settle over the fuel outlet and choke off the flow. That took a couple tries to siphon out the fuel, 1/2 inch hose, through a strainer to catch the bugs.

Apparently the bugs like skinny places and were hiding on the flat areas on the fuel filler neck. When the cap was removed to refuel I guess they got knocked into the tank. So if you have lots of stink-bugs in your area, I'd check that.

A little off topic, but last year my washing machine wouldn't run through a complete cycle - it would get stuck during the agitate cycle and just agitate forever - never went into drain & spin. Bought a new timer, and when I took the old timer out and took the cover off, I found a stink bug lodged in between two of the timer contacts that was the cause of the problem.

We have tons of the critters here in central MD, so I'm going to have to add that to my list of things to consider in the future when trying to diagnose tractor problems.

 

[iamhistory]

I finally got it running. I emptied the tank, again, blew out the lines, again, bled the injectors and changed the fuel.

Started up and ran like a champ.

I had done all of the things I've been posting (new filters, checked for debris, etc.) and trying things to no avail. I bled the injectors and the tractor ran better but not correctly at all. I dumped out the fuel I was using which was fairly fresh and got new.

I started her up and she's been running fine since.

Engines can do odd things sometimes. There was nothing to my knowledge that took place from the day I was running her just fine to the next day when it conked out that would cause the problems.

I hate to think someone put something in my fuel. It crossed my mind though.