fuel issues

[Jamoose]

Hello--
I have a NH TC 33D and over the past couple weeks it has been oddly losing power, unable to rev up and sustain RPMs etc. I checked the fuel filter today, pulled it, cleaned the bowl and removed some loose gunk. Then I attempted to bleed the system. Pulling the bleeder nut completely led to a slow flow of diesel. Leaving the nut mostly in (and still a touch loose) did not create bubbles or fuel flow while cranking as it has in the past when I bled the system before. Cranking did not get the engine to turn over so I cracked the top head of the fuel injector lines and did not get fuel or air while cranking. It seems that fuel is not making it up the injector lines and I'm wondering if the issue is a bad fuel pump. Any thoughts or recommendations as to how to assess this?

thanks
Jamus

 

[TnAndy]

Sure sounds like a lack of fuel problem.

Make sure first you're getting adequate flow thru that glass fuel bowl. Stand beside the tractor, rev it up until it starts loosing RPM, look at the glass bowl ? See ANY drop in the level in it ? Should see no air at all....if you do see any, work backwards from there. You're not getting enough fuel for the tractor to run above an idle level.

Check the little 'tick..tick...tick' booster pump is running. Turn the ignition on with the tractor off and listen for it. Not running, pump or electrical issue to the pump. Running ? Pull the line off on the inlet side of the glass fuel bowl and make SURE you have a good amount of fuel spurting out the hose....let it run and fill a gallon jug. Flow not strong, or intermittent ? Bad pump, OR tank obstruction not allowing fuel to get TO the booster pump. Booster pump is located back under the fuel tank somewhere.....no where near the engine. If you can't hear it from the tractor seat, leave the ignition on and go around back of the tractor.

Having had a tank obstruction twice with mine, I'd pull the hose off the tank and make dang sure it runs freely into a bucket, meaning it's getting TO the booster pump before replacing the pump, assuming you can hear it tick..tick...tick.

An in-tank obstruction will act exactly like you describe....you only have a little fuel flow out of the tank, which will allow the tractor to start, but won't let enough fuel to flow for higher RPM. The glass bowl will be full because enough flows to keep the tractor running at idle (or it dies, the ignition is left on and enough gets to the booster pump to fill the bowl, making it look normal...hence you HAVE to look at the bowl while the tractor is sputtering).

DO NOT get into suspecting you have a bad injector pump until you are 100% certain you have adequate flow of fuel TO the injector pump.

 

[ruffdog]

I don't think the TC33D has a "booster" pump or a lift pump as it is gravity fed from the tank. It is good to start from the tank first to check flow.

 

[mrfu]

I had a similar problem, when I started checking lines there was plenty of fuel getting to the filter housing but very little ended up at the filter.
Took the housing off and took it apart including the on/off valve. worked fine after that I think the on/off valve had enough crud in it to block the flow.
Tom

 

[Jamoose]

thank you for all the help with this. I think I have narrowed it down to a potential issue in the tank.
I pulled the fuel line to the fuel filter and drained the tank into a bucket. I was not impressed with the flow of fuel. I had expected that it would be full flow (as much as the hose could carry) and it was more of a trickle (I'd guess 1/4 flow). I blew air back into the tank and got more flow, although not what I would have fully expected. I refilled the tank with fresh fuel and it ran fine after that. I looked at how to get into the tank to see what was happening and could not clearly figure out how to get at it (behind housing). If anyone has thoughts as to how to get at it, that would be great.
When I first pulled the fuel filter, there was a gummy brown smudge, and from reading other posts am guessing it is an algae that formed in the tank. If that is indeed the culprit, are there any additives that can break it down in the tank so it passes (and save me a few hours pulling everything apart)? thanks again

 

[ruffdog]

If you can get a siphon hose to the bottom of the tank and near the outlet, suck the goo out. I use a larger ID hose like a 3/8"+ so the gunk doesn't plug it. I also have a oil/fuel sucker that works.

 

[TnAndy]

I looked at how to get into the tank to see what was happening and could not clearly figure out how to get at it (behind housing). If anyone has thoughts as to how to get at it, that would be great.

Both times with mine, it was a wasp (dirt daubber actually) floating over the small tank outlet, blocking flow. My tank outlet is only 1/4" ( or was....I've since fixed that). First time, dealer pulled the tank....flushed out the tank thru a clean rag and caught the bug....wrapped in with some plastic drill shavings from where I suspect they drilled the hole at the factory for the tank outlet fitting or the return fuel fitting.

Looked like a major pain to me, so when it happened out of warranty, I bought a cheap inspection camera with the 3' flex whip, drained the tank and LOOKED at the outlet.....sure enough, another wasp. Got a pair of grabber tongs and pulled that boy out. End of problem.

After the second round, I drilled out the plastic 1/4" outlet on the tank, and screwed one of these up inside the tank, then connected a 1/4" barb fitting to the screen. I figure that ought to put a stop to anything simply floating over the outlet hole....and since the last episode about 2013, it's worked fine.

FINGER STRAINERS from Aircraft Spruce

 

[OhioCowboy]

I know it's an older thread but just in case someone is having the same problem, mine did the exact same thing. I ended up using Hot Shot's Secret Diesel Fuel Additive in my fuel. That and putting a tee and valve in the fuel line between the fuel filter bowl and the tank I got a brass tee that included the valves. The reason for the tee was for when the tractor came to a stop a half mile from home, I can turn the fuel off, and blow the fuel between the filter and tank back into the tank. It dislodges the algae clogging the fuel line at the bottom of the tank and the fuel will run freely again. Eventually the Hot Shot's additive kills the algae and it becomes hardens up into little pieces that will make it through the hose into the bowl. Keep a few filters on hand for the next couple of weeks for the dead algae that comes out of the tank. Worked for me last summer.
Here is the 5/16" tee I used: