Micaiahfied

my last thread was on bacteria. i treated the tank and cycled the fuel through a filter, then replaced the filter. while it may still clog up future filters i don't beleive this to be the main issue at this point. when you fire it up it doesn't sound like it is firing all cylinders. it kinda cycles and lopes. at that point there is no throttle responce. messing with it (haven't found anything in particular) it will eventually even out. the idle is still to low so it shakes. once it evens out the thing will rev and and hold the highest RPM and runs great. BUT if you shut it down even for 5-10 seconds and start it back up it is right back to missing and barley running? any ideas?
fuel filters have been changed
IP was just rebuilt

Red3quarter

My dad had the same thing happen to a 3 cyl yanmar tractor that he has. It had bacteria growing in it. He took it to a good diesel shop to get it fixed and they told him that one of his injectors was fouled up by the bacteria that was growing in the fuel system. His acted similar to what you are describing to where it idled bad and ran horrible for a while, it also smoked alot. The diesel shop cleaned up the injectors and the rest of the fuel system and its ran fine ever since.

Micaiahfied

the injectors may need a good going through anyways, but if the tank is treated ("shock" treated) with double the biocide and i run the thing at WOT for a while do you think that may help to clean it up until we can get the injectors cleaned and pop tested somewhere?

bmoeller

Best way to clean up the system, is to take it all apart, and clean out EVERYTHING. Drop the tank, lines, filter, prefilter on the bottom side of the fuel heater,....... everything.

Just because you use the biocide, it won't flush it out.

Red3quarter

Bmoeller is right, just because you used biocide to clean it doesn't mean its all good inside. you really should just take the injectors out and have them cleaned and tested by a good shop. I'd clean everything really well before you put the injectors back in.

quantum610

Have several case loaders and had a very similar problem with one of them. Not all of them but this one in particular had an electric fuel pump in the tank that the wires got cut on. Had low power and would run fine until you started working it a little then the deisel would get warmed up and the lift pump couldn't hold enough pressure to the IP. Way less work than pulling injectors. I'm betting that the injectors are just fine considering that it runs fine at WFO. You have low pressure some where on the system.

Pentastar

It sounds like your engine is running out of fuel and it is an easy fix if I am right.Those old Case loaders had an external check valve in the fuel line between the tank and the filters that used to get dirt in it occasionally and when the engine was not running the fuel used to drain back to the tank from the filters and run the engine out of fuel which would act like yours until it picked up its prime again and then would run okay.
That check valve can be disassembled with the appropriate size wrenches and cleaned which should put you back in operation if that turns out to be the problem.The last one I did on a W20 was to the right of the engine looking at it from the rear about in line with the fan belts,just follow the feed line back from the filters.We had a W14 too but I can't remember where I found that one.Good Luck.Be sure you reinstall it into the fuel line in the same direction it came out.Ron G

Micaiahfied

pentastar, i took a good look at it today and can't seem to find an external check valve anywhere. but i do believe that air is entering the fuel system upon shutdown. i am trying to learn along with fixing this. i've never had to mess with the fuel system on my truck other than changing a fuel filter. the return line from the injectors runs down to the IP, there is a T sticking out of the IP and the lower line off the T runs back to the tank. with the loader off i turned on the elec fuel pump and pulled the return line coming form the injectors off... at this point a little stream of fuel came out form the IP. nothing out of the return line. this all seemed to make sence to me. if the loader is on there should still be a healthy amount of fuel cycling back into the tank correct? to cool the IP. i really do believe that for the most part the problem here is air getting back in upon shutdown... treating to the bacteria was going off what someone else said they had seen and the more i talk to the i figure out more and more how little they actually know. and help, thoughts, or just plain info on how everything works would help me out a ton! thanks
mark

Pentastar

Mark,there will be a check valve somewhere between the tank and the IP.Study the inlet to the pump and you should find an inline strainer and check valve if you disconnect the line going in.I have not had one apart in a while but you are on the right track,it will be a simple fix once you get it figured out.The electric pump in the tank is new to me also,it is possible but I don't think it is original equipment on a W14.Ron G

Micaiahfied

the elctric pump is inline between the tank and the IP... by the inline strainer are you talking about the glass strainer? that whole assembly bolts into the IP and looks like a lift pump to me. are you saying the check valve is part of that whole setup?

Pentastar

The strainer is a fine screen most likely after the sediment bowl.It probably is internal the way you explain it.I would think that the electric fuel pump would have one if nothing else does.In any case I would install one on the tank side of the pump and be done with it.You could use the same hardware that you would use with an inline fuel filter as that will be low pressure,if it works it was a cheap fix,if it does not you are not out much.I think it will work.If you want to search for the original check valve that is up to you.The fact that it has an electric pump tells me that it has been modified and I am sure there was a reason for it. No telling what was removed or what failed causing the modification.Ron G

Micaiahfied

ok, so it was suggested to me that i start the loader and sqeeze the rubber return line to see if it evens out. well i did that and it evened out almost immediately. i turned it off and on like 10 times with no problems. let it sit for 2 hours came back and it fired right off! can anyone explain to me why this worked? (i hopefully will find out from the person that suggested it but can't get to them right now)

Pentastar

There is a pressure relief (valve) I guess you would call it that maintains the positive pressure in the system before it releases to the bypass.You can feel it and sometimes hear the ball click into its seat as it responds to the calibrated spring pressure if you listen while priming the system by hand,that is using that plunger priming pump that you unscrew and pump the fuel pressure up with.You will see that it will only pump up just so hard and no more.I would reason that your squeezing the return line is doing what that little regulator is supposed to be doing and that is the result.If it was dirt and you dislodged it maybe you are fixed as long as the filter gets it the next time around.Let us know what it turns out to be.Ron G