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I seem to have narrowed down my problem with my diesel dozer to running the dang thing out of fuel when working on a hillside. It really doesn't run out of fuel as the tank typically still has 10 - 20 gallons in it when this happens, it is just that if I am pushing dirt up hill and working a hillside, after about 30 minutes with the tank down and the nose up, it starts sputtering and dies. Then I have to swing it around with the kubota and then bleed the injectors and then all is well again for another 20 - 30 minutes of hillside work. (BTW . . . my five year old found one of my 5/8" injector wrenches yesterday on the road I was building ) I have figured out now that if I just turn it around and run it down the hill nose first a few times (before it sputters), I can extend the run time between coughs and pukes but I still manage to run it dry every once in awhile which turns into a major pain depending on where it decides to die (think . . . inches from a cliff with rain pouring down and mud everywhere).

SO . . . the question is, will a fuel pump that runs between 2 and 4 psi hurt the injector pump? I can't see how it could, but knowing how much one of these cost to rebuilt, I really don't want to screw anything up. Also, since the diesel doesn't have a key or ignition system . . . any good ideas on how I should power the fuel pump up (other than using a switch which I am sure will get left on at some point and run the battery dead). I have noticed that the alternator will not begin charging till the oil pressure comes up . . . is there typically an oil pressure switch tied in with the charging system? Think it could be used to turn the fuel pump on? I know this isn't a stovebolt question, but this is in the interest of creating yet more space for stovebolts to live.

Before trying something like the fuel pump idea, make sure that is the problem.
Has the cat been sitting for a long time? Don't run it that often? It sounds like it works OK on level stuff. I'd first of all check all the lines leading up to the pump for any blockage. I'd also check the fuel, diesel doesn't like to sit for long periods of time (it starts to pick up contaminates). I'm sure you've seen those huge filters for diesel motors - they have them for a very good reason. Diesel can also pick up a bacteria that is hard to eliminate. Have you used any fuel conditioners? Some of them work quite well at preventing/solving fuel problems. Does your tank have some sort of venting so that you aren't having a vacuum lockup?
Fuel injection (diesel) pumps have a low side, where the fuel is pumped from the tank to the injection pump, and a high side. You may have to have the low side checked out. Does your manual say anythhing about it?

Ken,
The first thing, I'm not an expert, but I would want to take the fuel line loose at the first fuel filter and see what kind of flow there is when it quits running before moving it. There may be down by the frame a fuel strainer or it could be back by the bottom of the tank. Also if it has a shut-off valve at the tank, this is a good place to collect trash. I have seen a rock in a backhoe fuel tank that after time was completely ground round and would close off the fuel line. Of course this was on flat ground. If this has a lift pump some of those also had a screen on them. Now to the pump-if it is an IHC I would imagine it has a rosa-master CD pump. Some had a screen on the inlet line and there is also a check valve on the low end side or return line that will cause the engine to choke and die if it is sticking. If you have good flow to your filters this check valve would be the next thing I would want to check. Take it off and see how it runs. Yes, your electrical is being fed by the oil pressure switch. This makes it nice because it only turns on when it has oil pressure. I wouldn't be too quick to put a pump on it because it was designed to run without it. If you don't have a lift pump and the transfer pump is all in one they are still not that expensive. If you have to take it off, on the side of the pump will be a plate with two screws. Remove plate and rotate motor by hand until scribe lines line up, and if there is a pointer on front crank or back on the fly wheel this will have your pump in time on top dead center number 1 and ready for removal. Now you can take it to a diesel service and they can bench test it. I doubt you have to do this because it is probably in the line or there is a water separator you are not finding hidden down in the belly pan. If this doesn't help, send plane tickets! LOL

I took most every access panel and the seat base off the dozer and traced the fuel line all the way from the tank to the injector pump. There are no other pumps and only two filters (a twin bank) mounted on the side of the intake manifold. Both filters are new from about a month ago (this has been happening ever since I got the dozer moved to my property) and diesel is clean fresh DOT taxed stuff. I don't run it that often, but at least once or twice a month for a good 3 - 8 hour run. Sometimes I'll put 12 - 16 hours on it on a weekend.

When the dozer is level, I get a very small flow of fuel out of the line going into the injector pump, at this point the top of the tank is only about 20 inches above the injector input. When it is on any kind of incline . . . forget it. I have to remove the return line from the injectors and pressurize the tank to get the fuel up to the injector pump. It is usually easier to just chain up the blade and spin it with the kubota if I can get near to it. If the nose is down and tank up . . . bleed the injectors and go, no problem.

I'll clean all the lines and double check flow out of the bottom tank valve. Lisa is getting tired of washing jeans and sweatshirts that smell like diesel. :rolleyes:

Ken, Also check your fuel cap. I think it has a vent and it may be plugged-may look like a brass mesh.
Tell the wife that the smell is No. 2 cologne. :rolleyes:

It has to have some other pump, or one built in to the high pressure pump. All diesels have some sort of pick up pump. The high pressure side does not have enough suction to pull fuel. I can't believe Cat made a dozer with gravity feed fuel tank. Could there be a pump in the tank? Talk to you your local Cat dealer or equipment repair shop. This doesn't sound like a line or tank problem. If the tank is lower than the pump and there is no pickup pump, how can it run on a hill? There is no kind of handle or pump on the filter housing? How do you bleed the injectors? Keep us posted, Joe

Joe,

Don't be calling it a CAT! It is an International / Dresser TD7E! :o No pump other than the injector pump. When sitting level, the bottom of the tank is about 6 inches higher than the top of the injector pump. I'll give the Dresser / (Komatsu) dealer a call and see what they say . . . I bought a fuel pump from NAPA, but I could just as easily use it on something else if they say not to use it on the dozer.

Hey Lionel, Lisa says if Diesel is cologne #2, then that stinky stuff from the rear axle (used 90WT from the differential) must be cologne #1 . . . she don't like niether of them!

Ken, we use a oil pressure switch that turns on with about 5 psi of oil to run the engine hourmeter on the rental machines at Empire. If there is no oil galley plugs that the switch can go into, we splice into the R terminal wire for the alternator. If you are going to run the pump that is. I havent run into that much with the cats, but what kind of incline are we talking about. Anyway, I think that a low pressure pump would work, you dont have to worry too much about overpressurizing the system. Also you can prime the filters without that stupid little priming pump that never works. I dont know if that machine has an orificed connector on the outlet for the fuel system. For example, we have had a problem with 950G jerky hydraulic controls because we have too much flow going to the pilot valve, so we remove a full flow connector and install an orificed connector. It works fine then after. Let us know what happens. Also one other thing that we have run into is some people make fuel lines out of the aeroquip fittings, where you screw one piece into the end of the hose, and the hose peels up inside and creates a flapper which can close off the line when in a vacuum.

I would install an electic fuel pump in the line between the tank and the filters. If your filters have a port that you could tap in, install a fuel pressure gauge, prefferably between the filter and the injection pump. This will not help if you are getting air in the suction line from a crack or other defect.

About the easiest way to see if you are getting air in the suction line is to find a piece of clean, fuel resistant CLEAR hose. Splice it in as close the the injection pump inlet as possible and watch the line. Little foam streaks are tiny air leaks which usually do not present a problem. Bubbles, especially larger ones indicate a definite problem. If your engine has a Roosa-Master pump, running out of fuel is not a good deal since the only lubrication the pump gets is from the diesel fuel itself.

As you said, double check your lines for restrictions/blockages. It sounds like you are not getting enough fuel to keep up with demand, especially while pushing a load uphill. If you could load the engine the same while working downhill, does it behave the same way? Also make sure your return line is free. Roosa Master pumps will not work if the return is shut off or severly restricted. Sometimes this restriction is caused by the governor retainer ring deteriorating inside the pump, which clogs up the return line. If there are a bunch of little black pieces of stuff in your return line, your pump (and $1000+) are on their way out the door.

The oil pressure switch for the electic fuel pump is good, although I would add an override switch so that you could bleed the fuel system with the electic pump.

Hope this helps. You could get it running real good on level ground and trade up to a Deere--then I could help you more

Filling in the blanks . . . dozer pushes downhill great, on the flat great, it just plain screams when I open it up and have my ear plugs in so it doesn't hurt my ears, but when headed up hill more than about 15-30 degrees incline for more than about 15 minutes she starts to lose power, then sputter and the governor starts revving the engine due to rpm loss. Power is lost then it dies and I am back to the bleeding routine after I get the tank higher again or pressurize the tank after removing and plugging the return line.

Racecarl, the return line is clear. I am not sure what injector pump it has. It is a 78 4cylinder diesel D 239 made in Neuss Germany. Rated at 67HP@2200 rpm / 80HP@2300 rpm, this motor was made from 67 to 97 (the web is a cool place to find info)

I am sure the present injector pump "sucks" the fuel from the tank because at one time the fitting on the inlet of the filters was loose and it ran terrible till I found it. It must have been drawing a stream of bubbles in at that location. If there was a pump in the tank, that fitting would have been dripping fuel, instead it was dry as a bone and no dust collecting on it like would collect on a loose pressurized fitting.

I'll give the dealer a call just for peace of mind, but I am already planning on putting the pump in under the seat. I'll connect it up with the oil pressure switch in parallel with the ether injection button(not used anyway) so that I can bleed the system easy enough without butchering the dash with another hole for another switch.

I'll report back Saturday or Sunday with results.

[ 12-28-2001: Message edited by: Ken ]

I think your solution, using a small electric pump would work well. Also, you are good to keep the delivery pressure around 4#! Depending on the pump, a simple solution is to add a cup of ATF to a tank of fuel. F**d is advocating this as normal for the older IHC diesels because modern fuels don't have the lubricant needed for the metering rod in the pump... I have an older F-250 diesel, and it really suffers the moment I forget to add that cup!

Well, nothing ever goes as fast as you think it is going to go. I serviced the transmission and tried to grease the double U-Joint between the torque converter and the transmission. My grease gun coupler wouldn't fit between the U-Joint end caps to get grease into the front one. At any rate, fuel pump is installed and I wired it into an oil pressure switch that turns the alternator charging circuit and hour meter on/off. I also paralleled in the Ether Push-button (after disconnecting the Ether valve) so I can prime the system anytime I want just by pressing the button.

Fired right up and I adjusted the throttle linkage / idle speed / max governer speed, etc. I noticed the kill valve was being held open ever so slightly and backed the stop off about .030 inches and it seems to run just slightly smoother at idle than it did before. Took it out and worked a 30 degree hill HARD for about an hour, got the exhaust stack HOT!!! Never missed a beat and when I put it away it ran at a nice idle for about 10 minutes then I shut it down. The pump could be heard purring away for about 30 seconds before the oil pressure dropped enough to shut it off. Seems to have a bit more power than before and wraps up real nice, not sure if that is from the pump or from backing off the stop for the kill valve. All I know is I am a happy camper now and that road will be finished with about another 10 hours work!

Ken, I'm glad to hear you got your problem fixed. You probably need to use a needle on those u-joints. Glad you can push dirt at your place, here there is 4-5 inches frost in the ground. Could be worse-it could be snow!