Prime new fuel injector pump?

[Richard]

I assume there is no lift pump on the engine whatsoever. Just to make sure, look for a knob or lever than you can move in or out. It will be located on or by the injection pump. If you find one, you work it to get fuel into the pump. Be aware that some models of pumps use a lever running of off the cam. If the cam is in the wrong spot, the hand pump will not work. To rectify, bump the engine over.

Once you get fuel running to the pump, you should crack the lower bleed until the fuel runs out without any air bubbles in it. Next, do the same thing with the upper bleed.

Now that the injection pump is bled, you will probably have to bleed the air out of the injection lines. Turn the engine over and barely crack the line at the first injector. It make take awhile, as the lines are likely empty. When the fuel runs and the bubbles stop, tighten the nut while the engine is still turning. That cylinder should start firiing. Always tighten the nut with the engine turning, or you may let air back into the line. The lines must have no air in them, or it will not start.

Give the starter motor a rest for a few minutes and repeat. If the engine starts and runs roughly, you can crack the other lines while it is running. You can have more than one injector line cracked at a time. Just make sure you close them all while it is still turning. Don't crack more than one at a time with it running, though.

These are generic instructions, not specific to your machine.

Hey Snowridge...

That about sums up what I've done. I'll point out there is no transfer pump....it's gravity all the way (which is why I blew line clean, I feared maybe some obstruction)

As it is... the supply tube to the injection pump is flowing freely, though not forceably (since it's gravity).

As best I can tell, the injection pump itself is plumb full of fuel, especially so, since you can clearly see fuel heading back up the return line to the tank. If you remove the return line (and let the fuel dump out of it), as you crank engine again, you will see the air bubble move its way back UP the return line as it fills with fuel heading back to the tank.

I'll admit I'm not a mechanic. I'll also admit that I AM somewhat mechanically inclined, having tinkered on old cars back when...

This has me stumped. If I were to guess the problem, it would seem as though the pump itself is simply generating zero pressure inside of it.

Yet another question: If you have solid fuel running from the fuel return line back to the tank, can you use that to surmise that the pump itself is void of 99% air? In other words, could I still have a large air pocket inside the pump somewhere that's preventing the fuel from flowing through?

 

[6sunset6]

I am having almost the same problem with a Perkins 3 cyl on a MF TLB. posted in MF . I bled everything . Engine will only turn over for 5 sec then locks up. Loosened 2 of 3 injector lines , same thing. No start and will not turn over . new battery. Been working on this on and off for 2 months. I finally gave up and have a road service mechanic coming over Monday morning. Cold though.

 

[SnowRidge]

I am having almost the same problem with a Perkins 3 cyl on a MF TLB. posted in MF . I bled everything . Engine will only turn over for 5 sec then locks up. Loosened 2 of 3 injector lines , same thing. No start and will not turn over . new battery. Been working on this on and off for 2 months. I finally gave up and have a road service mechanic coming over Monday morning. Cold though.

Sounds like injector pump timing. Did you have the pump off?

 

[SnowRidge]

Hey Snowridge...

That about sums up what I've done. I'll point out there is no transfer pump....it's gravity all the way (which is why I blew line clean, I feared maybe some obstruction)

As it is... the supply tube to the injection pump is flowing freely, though not forceably (since it's gravity).

As best I can tell, the injection pump itself is plumb full of fuel, especially so, since you can clearly see fuel heading back up the return line to the tank. If you remove the return line (and let the fuel dump out of it), as you crank engine again, you will see the air bubble move its way back UP the return line as it fills with fuel heading back to the tank.

I'll admit I'm not a mechanic. I'll also admit that I AM somewhat mechanically inclined, having tinkered on old cars back when...

This has me stumped. If I were to guess the problem, it would seem as though the pump itself is simply generating zero pressure inside of it.

Yet another question: If you have solid fuel running from the fuel return line back to the tank, can you use that to surmise that the pump itself is void of 99% air? In other words, could I still have a large air pocket inside the pump somewhere that's preventing the fuel from flowing through?

To be clear, when you crack the injection lines at the injectors with the engine cranking, what exactly are you seeing?

 

[Richard]

To be clear, when you crack the injection lines at the injectors with the engine cranking, what exactly are you seeing?

Essentially nothing

To try to be 100% accurate, NOW that I've rebuggered around with it this afternoon, I AM getting some intermittent blips of fuel out of the tip so it's a bit damp from diesel spitting out.

NOT spitting out like you might think under pressure, but... well...perhaps you've seen an old Dawn (dishwashing liquid) bottle where after you use it, the residual liquid at the tip will allow/cause bubbles to gurgle out. That is kind of similar to what I'm seeing specifically at the injector end and in all honestly, I'm only seeing a bit MORE bubbly than that, at the actual outlet of the pump (should say outletS as in plural)

I swear... if I did not know this pump was a rebuilt... , meaning, if it had been on this tractor for a year in use... and exhibited these traits, I'd swear that it's bad.

I realize it COULD be bad.... I just don't see the odds as being too high that I'd have a pump go bad, exhibiting these no pumping traits, and replace bad pump with a rebuilt pump that exhibit the same traits.

Just doesn't make sense to me. That's why I started to fear the timing chain (or however this is driven internally) was broken. I took whole thing off again today to verify that the drive assembly was working (it was).

So, I now have a full tank of fuel, clean filter, blown clear lines from tank to filter and from filter to pump inlet. I've got a clean, free flow of fuel at the pump inlet. I've got positive mechanical drive TO the pump and yet, I'm getting spittle out of the 4 outlet holes.

Seems clear as a bell to me that this pump is indeed defective.

Is my logic bad?

Question for anyone who has experience with a pump while ON a test bench....

Exactly how do they test an injection pump???

They said they rebuilt this one but the fact is, it's a replacement. There is no way they could have taken the 36 year (or however long) pump we had that was beat up, ugly, oily, dinged.... and bring it back looking absolutely 100% factory NEW.

So... they swapped it for a rebuilt...fine. I've got no problem with that HOWEVER.... do they actually test a pump by putting it on a machine and letting it pump liquid?? (or air??.... anything???)

I'm going to give it another go tomorrow. If no luck, I think I might yank it off and take it back to them and see if they'll put it on their bench tester (if they have one) while I watch.

 

[SnowRidge]

From what I know about the process, they take the old pump, clean it up, replace a bunch of parts, reassemble it, and fit it to a test bench. The bench has instrumentation to determine the pressure and flow out of the pump.

My BIL used to do this for a living, so I know it's not rocket science. (I'll pay for that if he ever reads this. ) FWIW, I took one apart in the middle of a gritty boat yard, troubleshot it, and determine which part was bad. The owner went to town and got the part. We put it back together in the boat yard, stuck it back on the engine, and it worked fine, so I really know it's not rocket science.

Still, I think it is unlikely, but not impossible that you have a defective rebuild.

One thing to note, your symptoms would not result from a mistimed pump. That doesn't mean your pump is timed properly, just that even a good mistimed pump would deliver solid fuel to the injectors -- at the wrong time.

Are you sure you have all the air out of the injector lines? Any air at all and the engine will not run.

 

[Richard]

Are you sure you have all the air out of the injector lines? Any air at all and the engine will not run.

Perhaps you've missed one of my comments.

I don't even have the injector lines hooked up

I was not getting any leakage at the injector (when I DID hook the lines up) so I figured, let's simply take everything off of the output side of the pump to be sure the pump itself is putting out.

Once the pump is proven to be putting out and I'm not getting any fuel at the injectors, then I can look into the connection lines.

This isn't about the engine not running.... (well, I guess it is in a round about way ) but it's about having zero or shall I be more accurate to say, 1% of spittle at the pumps outlets.

Now...questioni: is THIS possible: Perhaps with the fuel lines that connect the pump to the injectors disconnected, there is a chance for air to gurgle back in the fuel outlets and in essence, allow the pump to simply recirculate the fuel within itself rather than actually push it OUTWARDS?

I deduce this can't be possible for 2 reasons:

1. I actually DID at first, have the lines to the injectors connected. Only after it didn't work, did I take them off to move closer to the source

2. Since this is a pump, I'd expect it to take its supply and push it only one way and by pushing only one way, fuel would HAVE to exit the 4 outlets and not swash around inside the pump.

 

[SnowRidge]

The pump only moves a tiny bit of fuel. It takes a long time to prime empty injector lines. How long did you crank it with the lines on and at least one of them cracked? The pump probably will not draw properly unless it is working against injectors and full lines. It is not designed to operate without the lines on it, not to mention the possibility of dirt getting in those openings.

 

[the bear]

do you have the fuel shut off on the pump its self?

 

[Willl]

for air to gurgle back in the fuel outlets

I don't believe so. If I'm not mistaken, there's a check valve on each outlet.