3340 Fuel problems

3340 We purchased new, first few years no problems, then the fuel problems started, what I noticed is the factory glass sediment bowl would fill half full of air while ideling or heavy loads, thought a break or crack in supply lines, replaced, still have problem, went to a eletrical fuel pump, same problem, removed the mech fuel pusher rod and install the pump back on the tractor, and completly by passed the mech pump sediment bowl and primer, new steel lines 3/8" diameter directly into a flow pump and not a pressure pump, thru a large canistor prefilter into the orignal factory secondary fuel filter, thought I had the problem fixed, still am running out of fuel, the tractor runs fine, then starts to stumble and rpm's drop to around 4-500, and slowly regains rpm's and it runs fine for awhile.

All lines from the outside of the tank are new and clean.

Is there any sort of valve or something factory installed inside the tank to the pickup lines? as I can not seem to find anywhere else that the fuel pump would be sucking air into the system, fuel tank was full when all this happened.

Fuel filter in factory canistor is clean and new, is there a check valve or bypass that could be failing on this factory cansitor filter and blocking fuel passage?

Tractor is probably 7-9 years old.

Any help will be greatly appreciated!

Eric B

Hi Eric

Just a couple of thoughts. Have you tried running it with a gallon can instead of the main tank ? Have you had the tank off and checked there isn't something floating around in there blocking the pipe ? I have also had problems when the bottom of the tank gets knocked up onto the suction pipe.

Regards

Mike

You seem to have done the right things. Mike's suggestion is a good one.

Have you checked that your tank is properly vented i.e. that air can get in to replace fuel being used? Easiest way to check this is just to leave the fuel filler cap off and let engine run.

Never really gave it a thought about the vent on the tank being plugged or restricted, will check this out, as time has passed I thought of removing the fuel line to the low pressure side of the injector and just running the pump thru the filters to make sure the pump can run for 15-20 minuets or longer without hesitation, that will quite possibly show if the pump is failing (new pump) or there is a blockage or restriction in the supply line to the pump.

I will keep you informed if any of the above items is the problem, as I am starting to run out of options.

Thank you for the suggestions!

Eric B