Thanks in advance for any help you all can provide. this machine is new to me, I have used it only for perhaps 3-5 hours since getting it 6 months ago. I have a case 580 K backhoe, 4-390 engine. Lucas CAV injector. Mod. 4670194EEU. I am not getting fuel out of the injector lines at the exit to the line. At Pump) Has always started instantly when cranked Tests conducted: 1) Mechanical fuel pump works well, Delivers fuel to the injector. With Bleed screws open, fuel spits out when cranked. 2) air completely bleed out- even filled unit by topping off at the return fitting. 3) solenoid working. Even removed plunger and reinstalled to insure port is open. 4) Shaft not broken, inspected visually thru side cover opening 5) head is not frozen, Shaft rotates when cranked, viewed with inlet line housing removed. 6) no external leakage. Motor shut down abruptly while running fine. I assumed fuel tank was empty Fuel gauge not working I also saw an earlier post about a fuel shut off beneath the throttle control/linkage. I am not familiar wtih that. Any ideas as to what is wrong.
U say when the bleed screw is open (by the name plate) fuel spits out.. loosening the bleed screw just a turn, does it SHOOT OUT IN A STREAM.? Or is it spitting in pulses..?? The reason I ask is u say it was running fine then shut off abruptly.. that’s no-bueno.. Never mind, I see where u took off the end plate..to check for the pump being seized.. The end plate needs to be torqued back on.. Have u checked the filter in the end plate.?? Do u have the throttle pulled to wide open when trying to bleed/start it.?? You’ll save your battery/starter if u fill up the filter with fuel before the next bleed..
Just so there’s no more confusion (on my part).. The injectors are in the head.. The INJECTION PUMP is the gizmo that feeds fuel TO the injectors..& lives on the side of the engine..
pump guy, thank you 1) referring to the Injector Pump ,sorry 2) when cranking the fuel spits out fuel from the top bleed screw in spurts, I believe coinciding with the mechanical fuel pump pulses. 3) I did not see a filter in the END PLATE. referring to the inlet for fuel coming from the two canister fuel filters at the very end of the injector pump. 4) Throttle was not pulled full open. Slightly open above idle.
FYI, I also topped off the fuel tank before any other tests
Don’t use the TOP bleed screw.. Use the one by the name plate. That’s gonna be the one that shoots about 3-4 ft..hopefully.. Did u have the end plate apart.?? I hope not, not w/o instructions.. we’ll tackle that later. In the meantime, bleed the pump using the other screw and lemme know what it did.. FILL THE FILTER UP FIRST.!!
You say the lift pump delivers fuel in spurts. Good volume ?? Have you changed the the in-line fuel filter that is located in the tube between the fuel tank and lift pump ? If you did change it, did you open the petcock while it was off to see if a good stream of fuel was coming out of the tank ?
new inline filter was installed about 2 hours of running time ago. Ther is no petcock on this machine. I suspect previous owner may have damage it and replaced it with a regular brass elbow. I have not removed the inline filter it since the problem occured but i could check the flow at the lift pump if you recommend that . I do believe i have no obstruction from the tank to the lift pump.
ok, end plate was easy on and off. 4 screws 8 mm. nothing funky about it. I lined up the small pin with the slot in the ring that is around the shaft when reinstalling. I'll take a picture to confirm we are talking about the same thing. I will also crank it with the lower bleed screw open and see how far it shoots. canister filter are full as I get flow from the first bleed screw at the top of the line coming from the lift pump.
attached are pictures off the entire injector pump and the end cap/fuel inlet portion. note the one output line is disconnected to test for output from the injector pump
Also fuel shoots out 4 ft easily when I leave it cracked open and crank the engine
Ok.. snug up that bleeder screw, pull the throttle to wide open and see if u get anything out of the pump.. U should do more than 1 line tho..
OK, I will open up all lines, open full throttle and give it a go. THANK YOU so much for your time
. Good luck
Forgot to tell you to leave the cap off the fuel tank while cranking..
Once u get fuel squirting out of the pump.. stop.. tighten up the lines AT THE PUMP..& loosen the lines AT THE INJECTORS.. & once u get fuel squirting out at the injectors.. Stop & tighten the lines.. Once/if it starts, let it run a few minutes at 1/2 throttle.. no less.(keep the rpm’s up)
got it
These can be a real bear to bleed.. I’ve had to fill the filter up 3x on one project I did..
OK, gas cap off- check all 4 lines disconnected at injector pump- completley disconnect with line pull away- check Full throttle set- check Crank engine in 15-20 second intervals with a short rest between cranking- check after first two runs, got a couple of drips from line output. next few runs got about 3-4 drips from each over 20 second cranking time - NO pressure, just solidary drips
I saw on another site regarding rebuilding that someone said they made an error on reassembling the throttle/ governor portion off the pump and screwed up the shut off. Is that really a thing on this injector pump? I have not seen anything like that in the schematics I have looked at. "only the solenoid shut off that I have addressed.
a thought, When I had the end cap off I did not want to crank the engine with the starter.( Trying to be cautious.) I just used a socket wrench on the pulley/drive gear nut. I only moved it a few degrees while watching the shaft turn. Is it possible the shaft has sheared where it is not visible from the side cover and the end of the shaft just moved because of a little friction between the two halves. I could redo that test more thoroughly.
test
Using the lower bleed screw tell us that it’s NOT LOCKED UP.. If it was, the fuel wouldn’t shoot out like it did..
To be doubly sure.. u can disconnect the inlet.. Fill the inlet with fuel, all the way to the top.. now crank the engine.. now check the level of the fuel in the end plate.. If the fuel got sucked down, the pump isn’t seized.. If it’s still at the same level.. it’s no bueno..
will try
fuel got sucked down but did not come out of the output end of the bajo fitting ( feeding the injector lines) plenty of fuel on the supply side. would pour out of line feeding the inlet if I did not cover tightly with my finger
do you do repairs ? I may be close in NC
Yes.. u can contact me directly at: my screen name at aoldotcom in your home email service.
Mr. Pump Guy, you do this entire forum a service. If you are ever in Northern Arizona, I would like to buy you a beer.
Thank u.. I try to be helpful..
good morning, FYI, not every reply comes thru on this forum. I saw the notice in my e-mail that you suggested the metering valve. I did check that it moved ok and was not stuck in the OFF position. It seemed to move ok but with a little drag. I'm going to pull the pump off the machine now and check everything on the work bench
found the problem, fuel Inlet end cap had a small screen filter that was Very clogged. SEE picture. Also polished up the metering valve so it moves very freely . fully assembled it now spits fuel when I spin the pump with my drill
Good catch.. we were gonna work towards that but u yanked it off before we got to it.. Glad u got it sorted out..
When it stops raining Ill install and go from there. Got new cannister filters and will replace those also to stay ahead of it. Funny, I watched about 20 different rebuild videos ( mostly slightly different model pumps) and only one mentioned that such a thing existed, That one vid was from a much older pump off a tractor. Never occurred to me until I was stripping down the pump on my workbench. Cleaned everything up and blew air thru all the ports and orifices. FYI, I sent you an e-mail as well. Thanks for all your help Mike.