BearKiller

At least I didn't have a trailer-load of cattle in this near-a-hundred degree heat.

I was at a light, the light turned green, I pulled into the BUSY intersection, and the engine fell out from under me.

I coaxed her to barely coast through the intersection and barely onto the shoulder.

Changed fuel-filter, crank her up and run until the filter was empty, then die.

Pump the manual pump, crank her up again, and run a few seconds, then die.

After a brisk trip up the road, behind a 4700 gallon tri-axle milk-truck, with a TOO SHORT log chain, I am home.

Took the line from the highest tank (full) and the draw-line loose at the fuel-tank selector.

Fuel pours freely all over me.

Bypass the selector to eliminate it as the culprit.

Get her started again, runs a few seconds, dies.

Take the fuel cap off to eliminate the vent being stopped up.

Still no go.

Each time it runs, the fuel-pressure gauge lays on ZERO, with no movement whatsoever.

Thank goodness I had the forethought to eliminate the hard-lines.

I took the lines loose at both sides of the piston-pump, connected them via a barb, thus by-passing the piston-pump.

Crank her up and she runs like a sawmill.

After it runs longer than it has, shut off, fire right up, shut off, fire right up.


This is a CARTER piston-pump, in a Cummins box, 3936320, brand-new from Cummins-Crosspoint in Louisville,KY, two months ago.

Has anyone else had a piston-pump just quit??

There was absolutely no warning.

I wonder if they will give me another, or just say tough luck.

I am gonna pull my load of hay into the barn, so I can unload it; then, I guess the old diaphragm will get screwed back on, until I can get another pump.

Thanks.

ChrisLib

That stinks, I guess the piston pump won`t bypass fuel thru it if goes belly up huh? Thats one upside of a diaphragm pump I guess, heck how many of those are running right now that are toast?

tomd

Good point, I guess it would be worth having an extra diaphragm pump with the older fuel line that had to be replaced with the upgrade.

BearKiller

With the piston-pump just hanging on the side of the engine, and the fuel-lines by-passed around it, I was able to get my load of hay into the barn, get it un-loaded, and get the truck back to a decent place to work on it -- all in sight of the house - - not like I went a hundred miles or more.

I guess I answered the question of the VE drawing through a bad piston-pump; it just don't happen.

I am going to re-install my old diaphragm-pump in the morning and see if I can't get the piston-pump replaced by the place where I got it.

Then, I am going to install an electric pump, in a valved by-pass line, for just such emergencies.

In the busy intersection, where this failure took place, I had just had a cell-phone woman run my light and cut me off.

Just when she got out of my way, the engine started dying.

I was too busy driving to even think about looking at the fuel-pressure gauge.

I had absolutely no warning, whatsoever; one minute, everything is fine, and the next, she's dead.

Times like this is when THREE big batteries SHINE; they cranked and cranked and kept on cranking.

I have only heard praise for the piston-lift-pumps; am I the only one to get a dud??

Ace

That is one of the (many) reasons I installed an electric in parallell with the piston pump when I did my fuel system upgrade. I used a check valve to isolate it so all that is needed to pump fuel electrically is a flick of the dash-mounted switch:

http://72.19.150.167/PhotoAlbum/Cars/Pics/fuelsys.jpg
http://72.19.150.167/PhotoAlbum/Cars/Pics/CTD_95.jpg
http://72.19.150.167/PhotoAlbum/Cars/Pics/CTD_96.jpg

tomd

I guess they dont call you ACE for nothng! wish I had the same.

BearKiller

I removed the piston-pump and it acted like it should work, when operated by hand.

Bear in mind that the only thing that would let the engine run, for more than a few seconds, was by-passing the piston-pump completely, and letting the vane-pump in the VE do the work; also, when I could get the engine to run, the fuel-pressure gauge wouldn't even wiggle.

The engine starts and runs so good, no one would suspect the lift-pump had been by-passed.

I clamped a three-foot length of hose to both ports of the piston-pump.

I stuck the DRAW end in a jug of diesel, and the other end in an empty jug.

I worked the primer-pump, until fuel flowed freely.

Then, I worked the operating rod (the one the cam works) and it was pumping more than the engine would need.

What gives??

I am thinking about looking inside and see if there may have been something sucked up in it.

Is it possible that a rubber line could be sucking together, cutting off the fuel, and the vane-pump just doesn't have enough suction to collapse it??

I am going to re-install the pump and see what happens.


I, too, am stepping up my plan to incorporate a by-pass electric pump.

BearKiller

After my scientific bench-test, I re-installed the piston-pump, fired her up, and the fuel-pressure gauge just layed on ZERO.

I gunned the engine, a few times, and no wiggle at all.

I shut it off, before it ran out of fuel.

Fuel pours so freely out the line from the tank, I believe it would run on gravity, alone.

Next step = put on the old diaphragm pump and see what happens.

I am sure happy that this happened only two miles from home.

What are the chances that the cam is not working the pump??

The only way I see this happening is if the lobe suddenly disappeared.

Boatnik

My fuel lines were crimped at the tank. I found them while doing a visual for a fuel line air leak. Probably not what you are experiencing but, could your fuel line be collapsing under vacuum of the pump but not when it gravity drains?

BearKiller

I really kind of wondered about that.

I just had the wife watch the fuel-pressure gauge, while I pumped the primer-pump.

I was able to push it to 5 PSI, by working the primer.

It would hold this pressure for some time.

When I got it pumped up to 5 PSI, I then fired it up, the gauge immediately went to ZERO.

There was no upward spike in pressure, just an immediate drop.

I am fixing to mount the old diaphragm pump; we will see what happens, then.


- -- -- -- -- -- -

On edit, I just got done running a hose from the piston-pump, into a jug of diesel.

I hand-primed the fuel-gauge up to about 4 PSI, cranked the engine, with the entire fuel-line system eliminated via my hose in a jug, and the fuel-pressure gauge fell to ZERO.

More to come.

wannadiesel

Sounds like you wiped the cam lobe. Time for an electric pump I guess.

ChrisLib

yeah, doesn`t sound good for that cam eccentric....you had better get one of those...what are they called....?Helix? cams I hear they have SUPER hardened eccentrics on em. Seriously tho, stinks about yer bad fortune but it will be interesting to see what the end result is...best of luck!

BearKiller

I put on the old diaphragm-pump, fired her up, and the fuel-pressure gauge went to climbing.

She held a steady 5-1/2 PSI at idle.

I started stripping my fittings off the piston-pump, just in case they will give me another, and may possibly have found the problem; but, I am not totally convinced it is enough to plumb stop things from working.

When I removed the intake hose-barb, I found a blob of stringy slimy gook on top of a screen.

There was a sizable amount of gook; but, the entire surface of the screen wasn't covered.

Of course, there is the possibility that it was all covered and I dis-lodged it when I removed the fitting that was screwed right in on top of it.

That still leaves the puzzle that I could hand-pump it and actually build pressure on the gauge.

I could loosen the fuel-line, at the filter, and pump fuel out until it was gushing.

With a hose stuck in a jug, and the pump not on the engine, I could work the operating rod and really make the fuel flow.

I just can't see that thing not even trying to make pressure, when on the running engine.

I guess it is possible that that blob of gook was immediately cutting things off.

As many times as I have had that thing on and off and on and off, I would think that at least once, I would have accidentally got the fuel to find a way through.

I intend to re-install the dumb thing, in the morning, and see what happens.

One thing for sure, as soon as I can lay hands on one, there is going to be a strainer/filter ahead of the pump.

I am just tickled it ain't the cam.

I am also elated that it happened when and where it did, two miles from home, with the weekend to figure it out.

wannadiesel

That is a puzzler. My first thought was "There's some gunk in the screen", but then I read further and saw you got it to make pressure by pumping the hand plunger. Really odd. I guess the higher flow rate sucked the goo up tight to the screen, but pumping by hand was slow enough that fuel got through.

BearKiller

I cleaned out the screen, as good as one can way down in a little hole.

I replaced all the fittings and re-installed the piston-pump, for probably the nineteenth time this weekend.

I spliced in one of those clear plastic cheapie three-dollar inline fuel filters, about six inches ahead of the piston-pump.

I figure any more gook that comes along will stop there first.

I primed her up and hit the starter.

She fired up and the fuel-pressure gauge immediately started to climb, settling at a steady 16 PSI, one PSI more than I had before.

I am as tickled as a little boy with a new red wagon.

Thanks, everyone, for your input on the situation.

That is the first time, in I can't remember when, that that truck has not came home under it's own power, and all on account of a pea-sized wad of slimy goo.

It makes me think of those commercials that show those robust healthy athletic types that get killed by some little speck of cholosterol going through their PUMP.