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HD5G w/271 detroit won't run

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Category: Allis Chalmers
Forum Name: Construction and other equipment
Forum Description: everything else with orange (or yellow) paint
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=21818
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Topic: HD5G w/271 detroit won't run

Posted By: youngrkp
Subject: HD5G w/271 detroit won't run
Date Posted: 05 Dec 2010 at 11:39am

After running my crawler an hour or two it lost power and died. I thought I had run it out of fuel, so I poured a few gallons of fuel in it. It started, ran a few seconds at almost idle speed and died.

Next I think I checked out the pump and filters by unhooking the fuel line coming out of the fuel pump. I think the flow looked good.

Yesterday I took off the air tube at the blower. The butterfly was wide open. I tried starting it with the tube off, no change. It starts runs a few seconds at almost idle speed and dies.

What do I check next?

Replies:

Posted By: Kipn
Date Posted: 05 Dec 2010 at 12:03pm

I'd recheck your fuel supply. Sounds like maybe your filters need replacing.

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1961 H3

Posted By: youngrkp
Date Posted: 05 Dec 2010 at 12:27pm

Thank you for your quick reply

I mounted a priming bulb in my fuel line and I can pump fuel though my filters.

Posted By: Coke-in-MN
Date Posted: 05 Dec 2010 at 12:34pm

On the back of the tank (lower side center) there is a low point drain and strainer, be sure you do not have ice in that to restrict fuel. Check filters on boths sides of engine , both primary and secondary.

The fuel shut off rod is into head area also working on govenor block .

If you say you have a good fuel flow from the pump and it still will not run , remove valve cover and crack or remove one of injector lines (carefuly as lines crack if tightened to much) to be sure you have fuel flow to injectors. Or just remove the fuel return line from back of head , it's less hassle. If you do not have fuel pressure gauge , then using a outside gauge make sure you have pressure.

a short poof of either should clear out any air bound injectors or fuel system, use 1/4" pipe plug in blower to inject either.

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Faith isn't a jump in the dark. It is a walk in the light. Faith is not guessing; it is knowing something.
"Challenges are what make life interesting; overcoming them is what makes life meaningful."

Posted By: youngrkp
Date Posted: 05 Dec 2010 at 1:59pm

I went out and unhook the fuel lines to the front cylinder injector, the most forward line did not have any fuel come out of it, the second line did have fuel come out of it when I cranked the motor. Is one line a fuel return?

All of the gages were trashed when I bought the machine 20 years ago.

Is that my next step find out the fuel pressure?

Posted By: Coke-in-MN
Date Posted: 05 Dec 2010 at 2:22pm

the one line is supply , other return , injectors are cooled by fuel flow which is constant theough the injector case. Fuel injection is done in injector itself by rocker and cam shaft.

If you have fuel then should fire, other thing might be if air cleaner is full of ice to shut off air supply. If it turns over and has smoke then you have fuel.

Speed of cranking is other thing as it needs to spin over and not groan over slowly. I would see if it will run on puff of either , I have run them a few minutes on it to get all the air out but usualy 71 serise will purge system quickly.

Posted By: Steve M C/IL
Date Posted: 05 Dec 2010 at 4:01pm

15 ft/lb on injector lines but you gotta have a line socket.Feels like alot.Too much cracks and too little can leak.Either one puts fuel in oil.If everything is plumbed correctly,the rt line is "in" and lft is "out" when looking from the rack control tube side of head.I don't know about that vintage but later there is a filter in the body on the inlet side.Loosen the return side and see if fuel is making it through the injector.Been too long ago.What drives the supply pump(besides the blower shaft)?How is it coupled?Could that have failed?

Posted By: Steve M C/IL
Date Posted: 05 Dec 2010 at 4:06pm

Another thought!Blower drives used to shear on 6-71's.Might want to pull air inlet off blower and see if lobes can be turned with engine dead. No air or fuel that way!

I can barely read the original post sooo after some straining I guess these suggestions have been addressed.Sorry

Posted By: youngrkp
Date Posted: 05 Dec 2010 at 4:17pm

I'm thinking I can rule out the air supply because I tried to run it with air cleaner bypassed and I visually saw the air shut butterfly was open.

My cranking speed is fast as I ever had. It does start and run on a puff of either. When I crank it I get white smoke out of the exhaust pipe, I give it a shot of either. it starts and dies.

Posted By: Steve M C/IL
Date Posted: 05 Dec 2010 at 4:27pm

Dumb question,but is the rack control moving with the throttle lever?With engine off the control tube should put all injectors in full fuel position(all the way in the body) when throttle is wide open and should pull them to fuel off when closed.If a Detroit has fuel and air it runs.

Posted By: youngrkp
Date Posted: 05 Dec 2010 at 5:11pm

I ran out tested my injectors, each injector is getting fuel, but does not let any fuel though the return side

does that mean the Injectors are the problem?

I had it backwards in my previous post, the front line is the fuel supply.

Posted By: Coke-in-MN
Date Posted: 05 Dec 2010 at 6:47pm

Check that rod to govenor that is also fuel shut off that it is working . If your getting fuel , white smoke, and runs on either ? unsure at that point except if somehow you don't have enough fuel.

Other thing is if the injectors are out of time , this is set by the plunger stroke height, set with DD plug gauge or vernier caliper. If the fuel is flowing to injector at pressuer then it should flow through to return line. At that point injector failure would be ?? but for both HV7 injectors to fail at same time odds against.

Check both filters close to be sure there is no water in them and no water got up into injectors. Should have filter below muffler . above fuel pump that is small spun cotton string filter, and on other side a cartrige type pleated filter, in can along side the oil filter.

Funny in a while back another person had problems with his 2-71 and swore filters were good , then changed them out anyway and it ran like new .

Posted By: Steve M C/IL
Date Posted: 05 Dec 2010 at 9:21pm

Fuel should come out the return side of injector all the time the engine is turning no matter what the rack position.You say you have fuel to the injectors but does it have any pressure behind it?Technically you're not supposed to have rack open if injectors have no fuel because it could score the plunger.Whenever the fuel system is opened up,you should crank engine with rack control tube in "off" position and return side of injector loosened or removed untill you get good fuel flow(no air bubbles)then reinstall/tighten return line.Then it should fire right up.

Posted By: youngrkp
Date Posted: 07 Dec 2010 at 8:42pm

Currently I have ordered new fuel filters and will put them in next weekend.

the linkage the goes to the injectors does not move when I move my throttle, but it does when I push and pull on the engine shutoff

thankyou Steve and Coke for your help

Posted By: Coke-in-MN
Date Posted: 07 Dec 2010 at 9:32pm

It won't as it is controlled by the govenor through a linkage .

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Faith isn't a jump in the dark. It is a walk in the light. Faith is not guessing; it is knowing something.
"Challenges are what make life interesting; overcoming them is what makes life meaningful."

Posted By: Coke-in-MN
Date Posted: 16 Dec 2010 at 6:34pm

Well mine is sitting the same as yours , dead and runs almost on one cylinder then kills , time to change filters and add some unleaded gas to summer fuel in the tank .

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Faith isn't a jump in the dark. It is a walk in the light. Faith is not guessing; it is knowing something.
"Challenges are what make life interesting; overcoming them is what makes life meaningful."

Posted By: youngrkp
Date Posted: 31 Dec 2010 at 6:11pm

Finally got my filters change today, the primary was terrible, sludge and water in the bottom and I question if the secondary filter was cleaning the fuel I don't think it was installed correctly. After the filter change my crawler would not start and fuel did not pump out of the return side of the injectors. Thinking the injectors are plugged I blew some air through the injectors, after priming the system with fuel the crawler started and ran fine for 10 minutes. The crawler die in the middle of my driveway half way the the barn where I like to store it for the winter. After I cleared the injectors with air and primed it the crawler start again and I drove it to the barn. Just as I got in the barn the motor started missing convincing me that I don't have my problem fixed.

Next spring I plan on installing a fuel gauge. Could low fuel pressure be my problem?

Posted By: Coke-in-MN
Date Posted: 31 Dec 2010 at 7:00pm

I just went through the same thing , was running and killed, changed filters and blew into tank to clear any ice from lines while they were off. New filters it ran for 3 hours at 50 PSI fuel pressure then went down to about 5 PSI and lost power but ran.

In shop now , primary filter was plugged with rust and ? what all , other filter still clean. drained tank and fuel is milky looking so might have some water in it also. Was going to clean tank but have not figured that yet as baffles keep from seeing full inside.

Had to replace one lift cylinder hose and add oil to trany and finals as long as in shop and warm.

If you put on a fuel pressure gage be sure it has a buffer screw in gage bottom of diaphragm with buffer otherwise gage will pulsate wildly.