AC5050 will only start with ether, please advise- we need this thing to run.

[Jerry/MT]

How many PSI should each cylinder average? We got about 250psi per. Compression is 17.1:1 , atmospheric pressure around 14.7 .. would be around 251psi.. right?

Compression ratio is a volume ratio NOT a pressure ratio!

The equation I use to calculate the compression pressure is based on the isentropic equation pV^gamma=Constant (eqn 1) where p is the pressure, V is the volume and gamma is the ratio of specific heats of air.

Sparing you all the gory details, the equation for what you see on a compression gauge;

delta p = p1 x [((compression ratio)^gamma) -1], (eqn 2)

where p1 is atmospheric pressure, gamma is 1.4 and delta p is the compression gauge pressure

Now the isentropic equation assumes constant mass in the cylinder but because of valve timing the mass in the real engine is not constant, and gamma is not 1.4. So K is a constant that adjusts the theoretical value of compression gauge pressure to account for this.

Eqn 2 then becomes delta p = K x p1 x [(compression ratio)^gamma -1] (eqn 3)

Gamma =1.4. From experience K is between 0.70 and 0.75.
So a compression ratio 6.0 engine would have compression gauge pressure at an atmospheric pressure of 14.7 psia would be 124.6 psig (K=0.75). This is what you could expect as a maximum for a engine in good mechanical condition.

I hope this helps you. As a general rule, minimum diesel compressionr pressure is ~ 325-375 psig for a 17: 1 compression ratio engine.


I ain't old, I just been used rough.

 

[UrbannGuerilla]

I hope the OP didn't get bad advice from someone about ether use.

I used the phrase "we" in my OP. It was actually my father that sprayed all the ether. (Not laying blame, but that's the truth) I have never used ether on an engine myself. When I originally saw him doing it I said "You shouldn't use that" (because I drive a diesel pickup, I at least know its a big no-no for engines w/ glow plugs- but the tractor doesn't have glow plugs, so I didn't know enough to press the issue.) His reply was something like "when i was young my brother worked on diesels and he used ether, and it was fine". (Which was probably accurate, 40 yrs ago) I looked up ether use on diesels (after the fact) and found out that method was eliminated from standard practice like 30 or 40 yrs ago. He's 70.

I think the OP is desperate and I wish I could help.

I am desperate. I have sprayed everything w/ a 4 gal backpack sprayer twice now (its prime bug season, and w/o spraying its all a loss) and it takes me 3-4 days to do everything, mixing, walking, pumping, walking, refilling, then more mixing, more walking, more pumping, & more refilling. Its SO HOT here in south GA right now, its brutal. Whatever it takes to get the peas to the finish line. While this barely works this year, next year I will have 5-10x the land to plant, and I HAVE TO get all this ironed out as soon as possible because I'm running myself into the ground trying to keep up right now... on top of all that, the peas are about 5 days out from first summer harvest so the storyline is about to get a LOT harder for me because I am also the picker and the sheller. God help me, I'm doing the best I can.

 

[5030]

After my YM2310 purchase I learned on this site to NEVER use ether on this tractor because it could break the rings.

The rings aren't the major issue as with broken rings it will still run (poorly). Bending the connecting rods is the bad actor ,because spraying ether into the intake, the either don't ignite when the injector is supposed to inject but when the either reaches the combustion point, regardless of where the piston is at in it's stroke so the either ignition can and will drive the piston down even if it's on the compression stroke but not over TDC, causing the weakest part ( the connecting rod) to bend.

Warm air is the best starting aid actually. Why Cummins uses a 'Mullion Heater' in the air intake. Warm air in the air intake contributes to the air temp in the combustion chamber and allows cold starting easier.

Back in the day when I had a 6.2 in my Fords pickup (terribly underpowered piece of junk), I always had a hair dryer handy to warm the intake air when cranking the engine. Warm air in the intake and it would always start right up.

 

[5030]

I used the phrase "we" in my OP. It was actually my father that sprayed all the ether. (Not laying blame, but that's the truth) I have never used ether on an engine myself. When I originally saw him doing it I said "You shouldn't use that" (because I drive a diesel pickup, I at least know its a big no-no for engines w/ glow plugs- but the tractor doesn't have glow plugs, so I didn't know enough to press the issue.) His reply was something like "when i was young my brother worked on diesels and he used ether, and it was fine". (Which was probably accurate, 40 yrs ago) I looked up ether use on diesels (after the fact) and found out that method was eliminated from standard practice like 30 or 40 yrs ago. He's 70.

I am desperate. I have sprayed everything w/ a 4 gal backpack sprayer twice now (its prime bug season, and w/o spraying its all a loss) and it takes me 3-4 days to do everything, mixing, walking, pumping, walking, refilling, then more mixing, more walking, more pumping, & more refilling. Its SO HOT here in south GA right now, its brutal. Whatever it takes to get the peas to the finish line. While this barely works this year, next year I will have 5-10x the land to plant, and I HAVE TO get all this ironed out as soon as possible because I'm running myself into the ground trying to keep up right now... on top of all that, the peas are about 5 days out from first summer harvest so the storyline is about to get a LOT harder for me because I am also the picker and the sheller. God help me, I'm doing the best I can.

Trying to wrap my head around spraying weeds with weed killer and spraying starting fluid into the combustion air intake on a diesel engine has to do with each other?????

 

[UrbannGuerilla]

Maybe injection pump timing is off. But keep spraying ether. Maybe that will eventually repair it

The injection pump was just rebuilt after this issue happened. We installed the rebuilt pump exactly as the old pump came off... where one sprocket has a white dot on it, and the other sprocket has a V that lines up with the dot. (We even took the rebuilt pump back once after the tractor still wouldn't start, just to be sure the rebuilt pump didn't have a problem. Rebuilder put it on a test bench and said everything is normal.) Also the lift pump is new, and the filters. We took the tube from the tank off to observe fuel free flowing out, and it wasn't a full tube worth of fuel - it was less a quarter tube worth of fuel coming out. It was difficult to blow air back into the tank so we used compressed air against the tube going directly to the tank, and it took a couple seconds, then we heard a pop of something that sounded like it broke loose, then bubbles in the tank. I don't know how much of the problem the fuel restriction was of the entire issue, but it certainly wasn't helping.

 

[WranglerX]

The injection pump was just rebuilt after this issue happened. We installed the rebuilt pump exactly as the old pump came off... where one sprocket has a white dot on it, and the other sprocket has a V that lines up with the dot. (We even took the rebuilt pump back once after the tractor still wouldn't start, just to be sure the rebuilt pump didn't have a problem. Rebuilder put it on a test bench and said everything is normal.) Also the lift pump is new, and the filters. We took the tube from the tank off to observe fuel free flowing out, and it wasn't a full tube worth of fuel - it was less a quarter tube worth of fuel coming out. It was difficult to blow air back into the tank so we used compressed air against the tube going directly to the tank, and it took a couple seconds, then we heard a pop of something that sounded like it broke loose, then bubbles in the tank. I don't know how much of the problem the fuel restriction was of the entire issue, but it certainly wasn't helping.

But does it start and run without spray bombing it....

 

[UrbannGuerilla]

But does it start and run without spray bombing it....

No sir it will not start on its own right now.

 

[ROUSTABOUT]

But you still have not checked push rods?

 

[Jerry/MT]

How many PSI should each cylinder average? We got about 250psi per. Compression is 17.1:1 , atmospheric pressure around 14.7 .. would be around 251psi.. right?

A brand new 17.1 compression ratio engine should give about 560 psig with a 14.7 psi ambient pressure. At 250 psi i doubt that you'd start that engine with that low of a compression pressure.

 

[5030]

Could be rings, could be a blown head gasket or even bent con rods from using either. Whatever it is, it needs to come apart, no choice in that matter.