fiel problem?

[KellyR]

First off, Happy New Year everyone!

A few days ago, I tried to start my 6/1 after letting it sit for a few months. I got
nothing when I spun the wheel. I took apart the fuel lines and discovered that
the line from the tank to the fuel filter had deteriorated. That's been
replaced, as has the fuel in the tank. The filter looked clean when I took it
apart. The line from the filter to the pump is clean. I cleaned the pump, but
I can''t tell if it's pushing high enough. The upshot is that I'm not getting
any fuel out of the pump. I'm spun it over with the line off at the top end of
the fuel pump and no fuels coming out. Help!

Kelly

[oliver90owner]

Remove the top-most part (under the high pressure line connector) part of the pump - the delivery valve.  You will then be able to bleed the pump.  Replace when fuel is running clear of air and continue to bleed to the injector as necessary.

Regards, RAB

[KellyR]

Thanks RAB.  I did as you suggested (and got my work out while doing it) and got all the air out.  FIred up no problem.  Thanks!

Kelly

[t19]

you might have air in the system, do a search on priming, and follow the steps to prime everything.... it will never start if its got air in it

[ronmar]

Thanks RAB.  I did as you suggested (and got my work out while doing it) and got all the air out.  FIred up no problem.  Thanks!

Kelly

One nice thing that I learned when I first started doing this is that you can position the flywheel so the cam that drives the fuel pump is at it's peak, then just rock the flywheel back and forth.  The cam will work the same regardless of which way it is rolling.  This is way easier(and faster) than spinning the wheel twice for a single pump stroke...

[mike90045]

I've got a similar situation - no fuel at the pump outlet.  Any good sketches or pics of the fuel pump, and where the nut under the outlet is?   Also, I can see loosening the top of the HP line, and getting a purge to there, but the injector is horizontal, and how do you purge air bubbles from that?

[oliver90owner]

mike90045

One is basically freeing the IP of air.  Once that is achieved the rest will follow becausre the pump will then move fuel past the delivery valve and it cannot (should not) return. 

The injector nozzle will normally be full of liquid so bleeding to the injector removes the slug of air in the high pressure fuel line so that it does not have to be driven through the injector, which can take some time and a great deal more effort than bleeding at the injector body.


Outlet on the IP is through the delivery valve (into the high pressure line), which is the top-most component part of that item.

Regards, RAB

[NoSpark]

I've run mine out of fuel a hundred times and although I don't like to have to bleed the system I also don't mind to much anymore. Here is what I do. Fill with fuel of course, crack bleeder screw at filter until fuel flows out, close screw, crack banjo bolt at fuel pump until fuel flows out, tighten banjo bolt, remove injector line at pump, remove fuel pump check valve until fuel flows out (with cutoff lever down), install check valve and injector line. Crack line at injector. I place my middle finger on the back side of the injector tappet (under the pump) and turn the flywheel (with decompression on) until I feel the tappet reach the top of its travel then turn the flywheel either forwards or backward until I the tappet is at its lowest point and continue to rock the flywheel back and forth until fuel comes out of cracked line at the injector. Tighten injector line and continue to rock flywheel until injector creaks four or five times then start as usual. Keeping your finger on the pump tappet the whole time allows you to only have to turn the flywheel enough to move the tappet up and down, because it can get tiring. The engine may run like a hit n miss for a minute until the air is fully purged. Now you could just remove the check valve and wait for the fuel but it might take a while and it may leave a pocket of air somewhere that would make the engine stall completely. Hope this helps somebody.

[ronmar]

I've got a similar situation - no fuel at the pump outlet.  Any good sketches or pics of the fuel pump, and where the nut under the outlet is?   Also, I can see loosening the top of the HP line, and getting a purge to there, but the injector is horizontal, and how do you purge air bubbles from that?

Mike
  The top of the IP has two "nuts" one smaller one on top of the larger one.  The smaller one on top is the compression nut that secures the injector hard line to the IP and is part of the injector hard line assembly.  The larger nut right below is the outlet valve assembly.  Underneath there is a spring and a little plunger assembly that acts like a check valve.  If your fuel is turned on, when you remove this larger nut and the spring underneath, fuel will flow out around the little plunger unless the injector cam lobe has the IP plunger raised.  The IP cylinder is fed fuel via a port inside the IP.  As the cam pushes up on the pump plunger, the pump piston blocks off this port.  This is the start of the injection stroke.  It is also the point at which you set the static IP timing.

The nut up on the injector is connected to a horizontal pipe into the injector, but the top of that pipe is pretty much the highest point in the system.  Bleeding off all the air to that point will get you enough hydraulic pressure at the injector to allow it to pop when the IP strokes.

[mike90045]

OK, I can use this description next month when I get back to the engine,  Thanks !!

Mike
  The top of the IP has two "nuts" one smaller one on top of the larger one.  The smaller one on top is the compression nut that secures the injector hard line to the IP and is part of the injector hard line assembly.  The larger nut right below is the outlet valve assembly.  Underneath there is a spring and a little plunger assembly that acts like a check valve.  If your fuel is turned on, when you remove this larger nut and the spring underneath, fuel will flow out around the little plunger unless the injector cam lobe has the IP plunger raised.  The IP cylinder is fed fuel via a port inside the IP.  As the cam pushes up on the pump plunger, the pump piston blocks off this port.  This is the start of the injection stroke.  It is also the point at which you set the static IP timing.

The nut up on the injector is connected to a horizontal pipe into the injector, but the top of that pipe is pretty much the highest point in the system.  Bleeding off all the air to that point will get you enough hydraulic pressure at the injector to allow it to pop when the IP strokes.

[NoSpark]

Oops. I should have mentioned that fuel will only flow out of the top of the injector when the plunger is down because the spill port needs to be uncovered. I also meant to get more specific on the check valve, thanks Ron. I have to admit that I usually just crack the banjo bolt then the injector line and rock the hell out the engine but for newbs it would be better to bleed all the way at first.

[ronmar]

Oops. I should have mentioned that fuel will only flow out of the top of the injector when the plunger is down because the spill port needs to be uncovered. I also meant to get more specific on the check valve, thanks Ron. I have to admit that I usually just crack the banjo bolt then the injector line and rock the hell out the engine but for newbs it would be better to bleed all the way at first.

If you have already gotten fuel thru it the first time, that is usually all that is needed.  One really excellent hint I received from someone with a lot more experience than me, was for a new engine to tap all the rubber lines in the fuel system to dislodge the bubbles.  The fuel entering the line for the first time will not completely wet the inner surface and air bubbles will form.  Engine vibrations will work these loose over time, and you will have to re-bleed this air out of the HP line a few times.  It is best to get it all out the first time.  If it has set for a while, and the first time you try and start it it barely catches, or has only a little white smoke for the first few firings is usually an indication that this air has made it's way to the hardline.

  The Injector is fired by hydraulic pressure, quite a lot of it.  the fluid is almost incompressible, so the IP builds tremendous pressure and transmits it to the injector hydraulically.  Air in the hard line between IP and injector acts like a spring.  Get enough air and the injector dosn't get enough pressure delivered to it to pop in the ammount of IP pump stroke available.  The check valve on the outlet of the IP should hold some pressure on the hardline, but I don't think it is really all that great at holding high pressure so i am sure some leaks back into the IP, propelled by the compressed air.  This usually means that it can't develop enough pressure to fire the injector untill you bleed off most all of the air.

[Tijean]

An air volume much larger than one pump strokes displacement that happens to be trapped between the injector pump plunger and the delivery check valve, will compress on each pump stroke but will not create enough pressure to open the delivery check valve, but instead, as soon as the pump plunger opens for the next intake the fuel is discharged back into the supply line since there is no check valve on the intake side of the injector pump. As ronmar says it  can just bounce back and forth with no net delivery volume past the discharge check valve.

Air that is in the high pressure line beyond the check vale would eventually be pumped out if you cranked long enough, but ahead of the delivery check valve, you could crank it forever with no joy. Good advice on tapping out the air bubbles.

[KellyR]

Tried to start the engine the other day and got nothing.  I spent a good deal of time trying to bleed, but still nothing happened.  Once again, I took everything apart.  I had previously replaced the fuel line from the tank to the filter, but double checked to see if there were any obstructions.  That was clean.  I cracked the line coming from the filter to the pump and had fuel coming out.  Then I cracked the banjo bolt.  No fuel!  Took that line off (which was the one that came with the engine originally) and it was full of gunk.  Replaced it with new line.  Did the bleeding and the engine fired up no problem.

Has anyone else had any problems with the fuel lines deteriorating?  The gunk that was in the lines was rubber coming off the interior of the lines.  My engine is a little over a year old, so I would think this would be a problem.  I'm using off-road (farm) diesel.  Might that be a cause?  MTW, the engine is a powersolutions JKSon.

Kelly

[xyzer]

I have had the fuel line go south after time....It is poor material  IMO and a for sure replace pror to first smoke....Until you have  bled your lister a couple of times you won't get it running until you are soaked in diesel. It takes practice !......