Oil & Fuel TN75 -- fuel system question

[jimg]

This past Sat I changed out my fuel filter and now my tractor isnt starting. Here's what lead up to that....

Changed out the filter as per the instructions in the OM...take filter off, spin new one on and fill filter via hand pump until fuel issues from the bleeder valve.

Start tractor...all good, idles for several minutes normally

Turned off tractor to check oil level (also changed oi at the same time)

Tried to restart tractor to move it back to the shed...the engine turns over but isnt starting

Manual says I ned to bleed the injectors which I do...however, no fuel is getting to the injectors if I follow the instructions (using hand pump). Working back from the injectors none of the lines have any appreciable amt of fuel in them even though the fuel filter is full. I cracked the filter output lines and some fuel comes out but it seems not nearly enough. Just wanted to add that its not been very cold here and even so I condition my fuel...so plugged lines I dont think is an issue. It appears that for whatever reason fuel isnt making it from the filter to the pump. Also it seems that using the hand pump (as per the instructions) I should see something eventually at the injector...but that never occurs. Any ideas??

One final observation...that back injector is very difficult to work on.

 

[Hooked_on_HP]

I am not familiar with your tractor, but whenever I bleed a fuel system I start at the filter and work toward the injectors. From your description it seems you have air trapped somewhere. I also fill the filter before installing if possible.
Bill

 

[jimg]

Right, this is what I thought...some sort of air lock. However, the manual doesnt lead to that conclusion. It leads you to believe that all will be corrected if you simply loosen the injector lines and use the hand pump to refill the down stream (from the filter) lines. So, why isnt fuel moving from the filter to the down stream lines when the pump is actuated???? I dont know...

 

[Eagleview]

I have a TL100A , it is the biggest pain in the....to get started again after running out . Ive bled everything , the only way it will start is to give it a sniff of Aerostart . As soon as it fires once , it's away . Ive bled every sort of machine you can think of , but logic plays no part in these things for some reason .

 

[LoneCowboy]

Usually on my TN, I bleed at the pump and after that it works fine.
Never had to bleed at the injectors.

It's real easy to strip the bleeder on the filter, if you do that, you'll get air in it all the time.

 

[jimg]

Yes, that was my experience previous to this. I never had to mess w/ the injectors (thankfully b/c its a huge pain to reach the back one).

Could you elaborate on the stripped bleeder stmt? How did you know it was stripped? Mine *seems* ok in that I didnt over tighten and it doesnt just spin in its hole. Nor does an fuel/air bypass in its tighten position.

 

[Willl]

You can not push fuel thru most injector pumps.

 

[jimg]

Right and thats not what is being discussed. According to the documented procedure the lines to the injectors should be disconnected and then the pump is actuated. LOL...then again the documented procedure says if lines fail to purge call your dealer. OK, I sort of failed on that point but thought I might get input here before going to the dealer....just in case the manual was wrong/misleading.

 

[Willl]

I was just going by what you said;

Also it seems that using the hand pump (as per the instructions) I should see something eventually at the injector

Obviously, I misinterpreted.

 

[Soundguy]

I read it that way too.. and i agree with you.. the I doubt the hand plunger will make fuel move to the injector, past the pump.. ( though I don't own that machine to say for certain).

All I've ever had to do on any diesel I've maintained is to fill the filter.. install.. open fuel, bleed past filter.. bleed at pump, and then bleed at injectors.. then wala... it starts. A few stubborn ones wanted a pull start the first time.. but usually starter gets it done. My 7610s spoils me with it's electric fuel pump!

soundguy

 

[Partspring]

Just some thoughts...
Start by checking basics. The fuel hand pump has a screen under the cap of hand pump (remove bolt with 10mm wrench) check that screen is clean. It is possible that hand pumping will move enough fuel to bleed but not enough for engine to run. IF screen looks good check that fuel solonoid is getting power. You should hear a click from the solonoid on the back of the injection pump when key is switched on. If not, check that solonoid is plugged in or possible blown fuse. If tractor still will not start you may have to bleed injectors. To do this, loosen injector line AT INJECTOR. (on top of head) Crank engine over like "normal starting" for a few seconds. Stop engine and snug injector line. If engine does not start on first injector, do the same to the next. It may be possible to bleed all injectors though not likely. After bleeding make sure all injector lines are snug and not leaking.
Hope this helps. Dan

Partspring original Ford/New Holland parts

 

[jimg]

In my original post I say that I cracked the injectors meaning I either loosened or completely disconnected the line to the injector. I first started by just cracking the line and then decided it would be best to disconnect. In any event I mistakenly cranked the engine in this state and while there was a bit of fuel at the loose injector line it seemed to me to not be nearly enough...only enough to make a small wet patch. After the initial discharge there was nothing else either when cranking or hand pumping.

I didnt check the screen or electrics...Ill do that when I get back home and see id that makes a diff.

Thanx again for all the ideas/questions...I very much appreciate it.

 

[Soundguy]

You do realize that the amount of fuel per injector squirt is -very- little... injector lines won't run a stream and pour out on the ground like a hose... it's very little fuel.. normally under high pop off pressure.. which, with the line cracked.. is reduced to -0-.. thus you have very little fuel under virtually no pressure.. a wet patch sounds about right..

soundguy

 

[jimg]

OK, thanx for the heads up. I didnt know that. When I get home Im going to run thru all the steaps again. Im sure it must be something Im doing wrong b/c I dont understand hat to expect.

 

[Eagleview]

My old bomb has no bleed screws , it has a plastic clip that holds the fuel pipe into the filter head with an 'O' ring seal . After the filter is primed via removing the pipe . All you can do then is pump the lift pump a couple more times until it builds pressure and goes limp . Not like the good old days with a bleed screw and a prime pump that will keep on pumping .

 

[jimg]

Got it started but did nothing else exc use the thermostarter several times. Guess all my horsing around put too much fuel into the cylinders...just a guess though. Thanx again for the help...