BX1800 Injection Pump Question

[jetattblue]

I have a BX1800 that I have been slowly rehabbing. I purchased it "hard to start." After taking apart the head, I found evidence of probable starter fluid use - cracked pistons. At any rate, I replaced the pistons, rings, etc. I have also replaced the fuel pump, all of the fuel filters, oil and oil filter, transmission fluid and filter.

Today, I went to start it, and it would never quite catch. I found that the fuel flows through the filters to the injection pump, but I am getting no fuel to the injector popes or at the injectors. I cracked the injectors thinking that it would bleed the system (although the bleeding procedure for this engine is just running the fuel pump for 30 seconds). At any rate, I get good pulsing fuel up to the injection pump, but nothing from there.

Also, I do see the fuel stop solenoid moving correctly based on whether the tractor is turned on or off.

Any ideas? Should I try to remove the injection pump and inspect it? Is there something that may have frozen in place from disuse?

I would appreciate any thoughts you may have. I am guessing that if it is an injection pump issue that originally caused the hard start, then perhaps they were using starter fluid, which resulted in the engine damages. Just a thought.

 

[North Idaho Wolfman]

There is only one part externally on the pump that can be checked, that would be the rack, if it's stuck it won't put out fuel.

You can pull the pump and make use the rack is moving, Caution, do not take any of the pump apart as there are several things that are set and adjusting them wrong will make the pump inoperable.

If the rack is stuck it's also going to be hard to get it out as the rack must be in a certain position for the mup to be removed from the block, there is a slot in the inside front for the rack pin to come out.

 

[jetattblue]

Thank you! I'll give that a try. It sat for a very long time, so it wouldn't surprise me if it was stuck in place. I'll let you know what I find!

There is only one part externally on the pump that can be checked, that would be the rack, if it's stuck it won't put out fuel.

You can pull the pump and make use the rack is moving, Caution, do not take any of the pump apart as there are several things that are set and adjusting them wrong will make the pump inoperable.

If the rack is stuck it's also going to be hard to get it out as the rack must be in a certain position for the mup to be removed from the block, there is a slot in the inside front for the rack pin to come out.

 

[jetattblue]

Quick update. I removed the pump and the control rod on the back moves the slide rack very easily. There is no tension to it all. Should there be a spring or something? Or, should it just slide freely?

 

[North Idaho Wolfman]

Quick update. I removed the pump and the control rod on the back moves the slide rack very easily. There is no tension to it all. Should there be a spring or something? Or, should it just slide freely?

Yes the rack should slide freely, no spring or spring tension.

So if the rack is moving freely and you are sure you are feeding fuel to the injection pump, and you've opened the bleeders to remove all air, also cracked, removed the Injection lines and your getting nothing out , then it's most likely gummed up and will need cleaned and or rebuilt.

Before having it rebuilt try bottle feeding the pump from a bottle and fuel line above the injection pump and see if that will get it primed.

Have you ever done a injection pump rebuild?
If not, it would be best if you had someone with experience and test equipment do it.

 

[jetattblue]

That makes sense. When I removed the injection pipes there was a Tibet bit of fuel in the top of each pump outlet. With it removed, is there anything that I can put in the top of each of the 3 holes that would safely dissolve gummed up fuel?

 

[North Idaho Wolfman]

That makes sense. When I removed the injection pipes there was a Tibet bit of fuel in the top of each pump outlet. With it removed, is there anything that I can put in the top of each of the 3 holes that would safely dissolve gummed up fuel?

No, because that's a one way valve in the pump.

But you can pull the feed and vent, turn it upside down and drain all the diesel out, then fill it with acetone or carb cleaner and with the pump upright slide the rack to the rear, have a block of wood the width of one pump roller and push the roller to pump it, it will take a little to get the fluid up the pump but when it comes out the top it's all the way threw it.
Do that to all the pumps then let it sit for about an hour or so, then drain all the cleaner out and again and repeat with diesel, once you have diesel out all the ports you can reinstall the pump, install all the lines tight on the pump and leave them snug loose at the injectors, then run the engine around till you get fuel at all the injector end of the lines, then tighten and it should run, if not you have bad injectors.

 

[jetattblue]

I will definitely give that a try! My injectors are freshly rebuilt so I***8217;m assuming they are good to go. One last question: should the Springs in the pump be very stiff? Mine are pretty stiff when you try to push the small rollers at the bottom; it takes a pretty good effort to get them to compress.

 

[North Idaho Wolfman]

I will definitely give that a try! My injectors are freshly rebuilt so I***8217;m assuming they are good to go. One last question: should the Springs in the pump be very stiff? Mine are pretty stiff when you try to push the small rollers at the bottom; it takes a pretty good effort to get them to compress.

Yes they are very hard to compress.

 

[jetattblue]

Alright. I've been looking through this more, and I'm wondering if my fuel flow is lower than it should be from the pump. Here are my observations:

1. Neither of the inline fuel filters fills with fuel after 30 seconds to a minute of the electric fuel pump running, and the pump is brand new. They both seem to have very little diesel in them. Should they be full or full-is if fuel is running?

2. Both with fuel pump running and without, I unhooked the hose attached to the lowest part of the fuel tank and nothing came out. On the BX1800, this is the opening under the operator's seat and it is the lowest point of the wing-shaped tank. After reattaching it, I unhooked the hose attached to the left wing - to the driver's left arm. Nothing came out. Shouldn't gas come out of the tank by gravity alone at the opening that is lowest? My fuel gauge indicates 1/2 tank, but I'm wondering if there is a blockage or something in the tank.

Any ideas? I wonder if the tank is actually empty, but the fuel sender is rusted/stuck and causing the gauge to read 1/2 full? I've got it mostly apart so I may check to see if there is any fuel in the tank.

 

[North Idaho Wolfman]

Shouldn't gas come out of the tank by gravity alone at the opening that is lowest?

If gas comes out of a diesel tank you have a serious issue.

Forget about the tank for now, put the injection pump back in and bottle feed the pump from above it and see if it will run!

 

[jetattblue]

That would be a problem! I meant to say diesel.

Thank you so much for the help. Here's what happened this morning. I plumbed my gas line to a milk jug full of fresh diesel, and the tractor kicked off after just a few tries. The next try, it fired right up with no hesitation and no smoke! It ran and idled really well.

Since this is the first engine I have ever rebuilt, I cracked each injector, and the engine stumbled each time - so it appears that all cylinders are firing.

I removed the gas tank, and, yep, it was completely dry although my fuel gauge read 1/2 full. I removed the fuel sender, and it was rusted pretty bad and felt stiff. The good news is that the float moved very well, and it was in great shape.

So, I've ordered a new fuel sending unit, and I can start to re-install everything on the front of the tractor while I'm waiting for that. I'm also going to install new fuel lines since these look pretty nasty. All of this is really easy to do while it's taken apart.

Thank you, thank you, for all of your help!

 

[Russell King]

You may need to clean the inside of the fuel tank out if there is any rust in it. The flakes of rust will clog the fuel line


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