Diesel injectors just will not fire after filter plugging/swap

[RNeumann]

Algae?

 

[Jerry/MT]

Meh, I'm used to it being -28. It hadn't been above -20 for 2 weeks up until today, when the weather finally broke and I'm smiling in the snow at -4.

It runs now, but I couldn't tell you why. The answer was just to keep on keepin' on until it fired, I suppose. I can tell you what was wrong with it - many things.

- first off, the primer lever has long been broken off before I got the machine. I have to bleed by cranking. In the cold this is just stupid, hard on the battery and the machine, so I pulled the lift pump off the side of the motor so I could pump it manually. This was a huge help.

- I had used the wrong bleed screw on the filter to get started. I bled the clean side, top and center of the filter. Should have bled the dirty side (crack the return line), this one has way more air in it. The clean side appeared to bleed clean, but maybe small bubbles were sneaking through.
- bled this port for 15 minutes and still getting gobs of air. Crack downstream of fuel pump. It is pumping bubbly fuel.
- when reinstalling the separator bowl, it was so cold the gasket didn't deform, allowing air to be sucked in. But why would it pull air through here, the tank is much less restriction? Unless...
- tank pickup is waxed AGAIN (or still waxed), so it pulls through the gasket instead of from the tank. Heat the petcock until it flows well.
- also, the screen in the separator is waxed and doesn't look like it because it's wet. Burnt that off with the heat gun. Heat the gasket until it's nice and soft, then reinstall.
- not drawing air anymore, but also not putting out much fuel. Let's check the lift pump.
- the screen in the lift pump is waxed and there is also a ton of gunk in the pump, piled up before the screen. Screen did its job! Carb cleaner and rags and flush it with diesel. Burn the screen off with the heat gun.
- NOW we are getting some good flow of clean fuel. Bleed the filter properly. Bleed the injection pump, rotate motor, repeat 3x. Bleed the injector lines.
- **** it, it still won't even puff a ghost. What could be wrong.

- time to step it up a notch. Pull an injector. Don't worry guys, I know injectors are both dangerous and fragile, I've done this before, I rebuilt the whole top end of this tractor.
- flip the injector out, bleed line and hook it up, sure enough it is not popping. What am I going to do.
- Ok, what's left to try. Let's disassemble the injector. This I have NOT done before but I have a procedure in the shop manual and a long history with fixing tiny, sensitive stuff.
- there is gunk in the injector. A bit of scuffing on the side of the pintle, fortunately not on any working surfaces. Huh. Didn't expect that. Clean it up well with carb cleaner. Wash it all in diesel.
- reinstall injector. Line up fuel line. Flip the starter to purge that line in case anything got on the end.
- Unexpectedly, a tiny puff of smoke comes out the exhaust. Oh boy! But wait. I haven't even connected the injector I cleaned up. Oh well, let's run with it.
- loosely connect the injector nut, I don't want to disturb this fragile state. Glow plugs on. Crank until it pops and sputters into life. Tighten the line on this injector and it smooths up and runs perfectly. Why? You tell me!


So what did we learn from this terrible ordeal?
- NO SUMMER FUEL IN DECEMBER, even if it's above freezing, and there is additive in the fuel. It could be cold tomorrow and stay that way. This is what got me into this mess.
- in a filter plugging incident, check EVERY filter and screen in the machine, even the ones you don't know are there.
- always warm rubber seals before installing in a cold environment.
- I need a 12V fuel/filter preheater. Maybe a plug in fuel tank heater even.
- I need to pull and clean the rest of my injectors on a nice day. Fairly soon, I think.
- I could use a secondary filter or at least should start using a filter funnel. Apparently our fuel is full of junk.
- Apparently chickens are tougher than they look. Even if they get loose and wander off, they can eat snow and survive 2 weeks below -20 out in the bin yard eating spilled grain. They get enough shelter hiding under broken down tractors.

Clean fuel with the proper composition for the ambient temperature the machine is operating in is a must! You found that out the hard way at below zero temps.

Try to keep your tractor tank full to minimize condensation. If your fuel filter has a drain, use it regularly to get rid of water. Check the strainer in the tank occasionally. If you have contaminated fuel your tank is contaminated and you need to consider draining it and cleaning it. Check you supply tank and consider cleaning that also.

There is nothing so miserable as to try to sort out a no start at -28Fand critters need feeding. So manage the cleanliness of your fuel supply, use winter fuel as appropriate, and you can minimize the cold weather starting problems! Diesels have a tough enough time starting in cold weather without the problems of inadequate fuel delivery!
Glad you were able to work through it and get going. Merry Christmas.

 

[rectifier]

Our supply tanks hold summer fuel, and they are angled and get drained regularly. I usually bring jerry cans of fuel for the chore tractor in the winter, and normally the fuel turns over as the temperatures drop, but I got caught on this one with heavy in the tank. Certainly I will never try to run with it again!

I've started using a "Mr. Funnel" water separating funnel every time I fuel anything other than the car. I haven't caught any water yet but I have caught crud even in the "clean" jerry can right from the pumps. No wonder there was so much junk on the filter. Come spring I'll be pulling the tank and cleaning it fully.

After going through the system again on a nice day I have a tip for this pump. I think I'll put it in its own thread so it's easy to find. The bleeding instructions are inadequate - a large volume of air can be found at the very end of the procedure by cracking the upper bleed screw and then cranking the motor. Simply turning the motor 1/2 turn and pumping the primer as specified will not clear this air. As such it will have to come out through the injector lines... that was the big problem in this bleeding incident.