Detroit 353

[Blueboy]

Beautiful day for digging. So I thought I would dig up some pine tree stumps. I couldn’t be happier with how the hydraulics work! Thanks to HEF!
I carried the stumps to the back 40 and on the way back is a small grade about 175 yards long. Problem is the engine acted like it was loosing power. I could give it more throttle but I didn’t want to push the issue. Once I got back if I let it idle it would die. It would fire right back up and idle somewhat ok but not like it would before the round trip. The machine had no problem digging again. But it almost acts like the engine is over heating. Fluids and filters are good and has a new water pump. The temp gauge does work but I’m not sure how accurate it is. Engine is a 353 Detroit. As discussed before this backhoe (1983 Dynahoe) sat for many years. I thought about running some injector cleaner threw it.
Digging I ran the engine about 1500 rpm and driving back was full rpm at 2500.

Any ideas?
Thanks, Blue

 

[old-iron-habit]

I am making the assumption that you are not running at high governed RPM when digging and or when pulling the grade. The Detroits do not have any lugging power, They are designed to be run screaming wide open. If it bogs with the throttle wide open then you probably need fuel filters. Fill both new ones with fuel before installing them and it should start right back up.

EDIT: reread your post. High end governed RPM should be 2700 to 2750 on the 353s. If it bogs like it is running out of fuel it is probably the filters. If it is low on power open it up wide open and if the hill is steep enough you may have to select a lower gear. You could use a heat gun if you suspect overheating but it sounds like fuel to me. Is there still ancient fuel in it or has the tank been flushed and new fuel filled.

 

[Delmer]

No smoke-no fuel.

I didn't go back through the history, but I'd guess it's bigger junk than injector cleaner will cure. Like a plugged screen, fitting, filter etc.

 

[Blueboy]

High end governed RPM should be 2700 to 2750 on the 353s. If it bogs like it is running out of fuel it is probably the filters. If it is low on power open it up wide open and if the hill is steep enough you may have to select a lower gear. You could use a heat gun if you suspect overheating but it sounds like fuel to me. Is there still ancient fuel in it or has the tank been flushed and new fuel filled.

Ok, I thought 2500 was max. It will go to 2700+ tho. Engine doesn't seem to be bogging down, no excessive black smoke (to the best of my knowledge). It was in 1st gear already. Fuel is 100% new.

No smoke-no fuel.

Should there be a lot of black smoke?

 

[Dickjr.]

I would suspect filters as well. One other possibility would be the rack isn't giving it full fuel when needed. There are shims in the governor as well that set the rpm. There could possibly be dirt or something restricting the governor and rack action. What does that backhoe weigh , the 3-53 is good for 75 hp , it may be a bit underpowered for that tractor.

 

[Delmer]

If you're loading the engine it should smoke more than usual. Probably much more black smoke than usual.

It is an overloaded tractor that will grunt going up hill, but it should never die at idle, or idle differently after a hard pull. If you're concerned it's overheating, use an infra red thermometer to check the water pump temp etc, to verify the temperature gauge is working correctly.

 

[Blueboy]

What does that backhoe weigh

Book says just under 24000 But it's geared really low. I'm told these machines are slow moving... And from what I see their right.


I guess the lack of fuel would be most likely. What else is there... If it's not getting enough fuel will a diesel engine run like a lean gas engine? Obviously I don't want to melt some pistons. It seems to have power, it's just towards the end of the haul the engine has a different sound.
Is it possible the innards are overheating and the block isn't transferring the heat to the coolant quick enough to register at the gauge?

 

[hetkind]

I would clean the fuel system, test the injector pump and the like. It sounds like a fuel issue to me. Unlike most engines those detroits use a cam operated injector, gear driven IIRC. I think the injectors are UNDER the valve cover...

Howard

 

[old-iron-habit]

I would put in new filters and run it for a while if the temp in not overheating. They normally come out if it with some stedy work. Open it all the way up when you get in a pull. They need to scream and are made to run against the governor.

 

[kshansen]

I would clean the fuel system, test the injector pump and the like. It sounds like a fuel issue to me. Unlike most engines those detroits use a cam operated injector, gear driven IIRC. I think the injectors are UNDER the valve cover...

Howard

On a Detroit the "Fuel Pump" is just a simple gear pump to supply fuel to the injectors. All timing and injection pressure is a function of the injectors. Governor is connected to the injectors by linkage.

 

[Delmer]

towards the end of the haul the engine has a different sound.


Is it possible the innards are overheating and the block isn't transferring the heat to the coolant quick enough to register at the gauge?

No, basically if the coolant is under 200, then the engine is not overheating. Drain a cup of coolant from either the bottom of the block or radiator after it's been running but not HOT, if it's a see through green, and there's nothing major on the bottom then the cooling system is fine for our purposes.

The changing sound, along with the other symptoms sound like some sort of fuel starvation. That doesn't make it run any leaner, a diesel almost always runs lean because the fuel is the only thing controlled. That blower is always blowing the same amount of air whether the engine is idling or full power.

You could put a fuel pressure/vacuum gauge in the system if you wanted to be sure what was happening.

 

[Zed]

I agree it seems like a fuel issue. As stated the fuel system is quite simple, a gear pump supplies fuel pressure into the cylinder head and then via fuel lines to injectors. If the fuel is good, filters are changed so I'd check the actual fuel pressure. Tee into the hose that supplies fuel to the head. Anyone out there know the book spec for fuel pressure? I think it's around 50 - 60 PSI. One thing we always did with curly fuel issues like this was to do a test using a seperate fuel supply and hoses. We'd run hoses from a jerry can, one to the fuel pump (supply) the other a clear rubber hose from the restrictor fitting on the head. This lets you see if there's any bubbles in the fuel going back to the tank.

 

[Scrub Puller]

Yair . . .

Delmer

That blower is always blowing the same amount of air whether the engine is idling or full power.

Is that what you meant or did you mean the same amount of air per revolution

Cheers.

 

[lantraxco]

Scrub, Right on, the faster she goes, the faster she blows... gotta love it. Now if we add a turbo and a bypass valve... a silver 53!

 

[repowerguy]

I'll second the temp fuel can, I have seen fuel supply issues being a clogged elbow at the tank many times. Had a similar problem on a grove crane with a 6v-53, that after some head scratching found a chunk of wood and some straw in the suction tube. After some digging and banging, out came the obstruction and that old screamin Lena was back making money.

 

[Delmer]

Yair . . .

Delmer



Is that what you meant or did you mean the same amount of air per revolution

Cheers.

Don't confuse us with facts. And a turbo on a Detroit just isn't right.

"burning too lean" just doesn't apply to a diesel. Now if the timing is messed up, or the engine is detonating because it's overheated that could do some damage. Most likely here the cylinders aren't firing evenly because the fuel supply is inconsistent?

 

[kshansen]

I'll second the temp fuel can, I have seen fuel supply issues being a clogged elbow at the tank many times. Had a similar problem on a grove crane with a 6v-53, that after some head scratching found a chunk of wood and some straw in the suction tube. After some digging and banging, out came the obstruction and that old screamin Lena was back making money.

Make that a third for the temp supply of go juice!

Not the same engine but where I worked we had a 710 JD that would work fine till you tried traveling up the grade out of the pit in a higher gear. Took fuel cap off to check fuel level and noticed a vacuum. A quick investigation found the fuel cap had one of those vents that are like a bunch of little brass beads stuck together. Just had a good coat of mud plugging it. Quick flushing out with brake clean and a blast of air and the old tractor would pull the same hill in top gear.

One thing that you could also do if you have an infer-red heat gun would be to point it at the exhaust manifold ports near the head just to see if there is a major difference in the temps indicating a possible weak cylinder.

 

[hetkind]

We used to pull the exhaust manifold off the motor and watch it run to see which cylinder was bad...and the old DD 53, 61, 73, 92 and the like, could come with the supercharger or normally aspirated. The supercharger gave more power, obviously, with without it, maintenance costs were lower.

I work on those in the early 80's and not much since.

Howard

 

[old-iron-habit]

A good test of the fuel pump back seal is to put an electric pump in line before the engine driven fuel pump. The pump is a simple little gear pump that develops 60 PSI normally. I have had the seal on the pumps driven shaft side fail and suck air when the engine is running wide open and work fine at lesser RPM. You can often see a fuel leak at the back of the pump with an electric pump providing pressure with the engine not turning.

I did not see anything in your post about missing. Sounds like low fuel or just low on power. As it sounds like it is god enough to use, I would still run it a number of hours working it hard as you can before I got to carried away dumping a bunch of money into it. I have had more than one run less than perfect after setting for years and then cleared up after using it for a bit. There is a possibility that the rack needs to be run if it has a lot of hours on it but it could also be that the rings are a bit sticky and a few warm up/ cool down cycles will cure it.

 

[Scrub Puller]

Yair . . .

hetkind.

could come with the supercharger or normally aspirated.

Respectfully I must disagree . . . the Detroit two strokes would not run with out the blower, or not in any useful way.

They required the blower for scavenging and it was an integral part of the combustion system.

Turbos were an add on that improved the performance curve and assisted the engine to hang on instead of dropping it's guts from lack of boost as it lost the revs.

Cheers.