JD 2240 Runaway engine, resulted from return fuel hose getting disconnected

[fritza2tt]

The fuel to the tank return line got disconnected and sprayed fuel into the air intake. This caused the engine to run away uncontrolably and sever engine knock developed. This happened to me about four years ago with no after effects and then again yesterday, though this time with disastrous results. It is possible to start the engine but this ime the connecting rod bangs furioussly as soon as the engine starts to run. I now must decide whethet to scrap this 34 year old tractor or try to fix it. My thought is that first a compression check needs to be made to see how many cylinders are affected. If it is only one cylinder it should be possible to replace just that piston, hoping that the connecting rod is still ok. Other parts that might need to be replaced are the intake and exhaust valves, the cylinder itself and the upper connecting rod bearing. Has any one out there had any experience doing a repair like this?

 

[Briana03]

Hello, I moved your thread to the John Deere Owning and Operating forum. Best of luck and welcome to TractorByNet.com!

 

[Tx Jim]

In all my years of JD experience I've never heard of that happening. If return fuel sprayed at sufficient PSI to make it to air intake hole then the return line is PLUGGED. I think an engine dis-assembly is in order.

 

[cottermac]

I did rebuild on an engine one time that ran away and the only advice I can give is tear it down and do alot of inspecting. The one I did cracked 2 cylinder sleeves and melted pistons down like candles. If I remember right we used all new part to put it back together. I would also call around or do internet search for salvage engine for a replacement just to compare the cost. Hopefully you got it shut down before to much damage was done and it will be a easy fix. Best of luck

 

[fritza2tt]

Jim, this is a JD 2240 design flaw. The engine running away happened to me twice. Excess fuel from the injectors is routed through a small rubber hose back to the tank filler neck. The hose is attached there and held with a clamp. Over time the connection becomes lose and the hose slips off. Fuel continues to flow with the engine running and the spray is picked up by the fan. The fuel air mixture becomes combustible, gets sucked in by the engine air intake and the first thing you notice is engine ping. When I heard the engine ping, I naturally was concerned, stepped on the clutch and that's when the engine ran away. The proper procedure would have been to stay in gear and throttle down. The engine would then have died quickly and no damage would have occurred. In my case, the engine ran away but quickly died when I stopped the tractor. This was four years ago. The tractor continued to work perfectly until yesterday, when my son in law had the same experience. He hesitated too long and the engine trew a rod and then stopped. I nevertheless was able to to start the engine again. It ran for a few seconds making terrible banging noises. I quickly shut it down. The dealer was notified and I got an estimate for a $2,500 to $2,700 repair bill. :-(

 

[Tx Jim]

If it's a 2240 design flaw it would also be a design flaw on many other Dubuque/Mannheim built JD utility tractors. I worked for a JD dealer from the mid 60's through the late 80's and have been around/owned JD tractors since. As I stated I've never heard of this design flaw you refer to. I curious if YOU have to ever looked inside the diesel fuel tank filler neck while a diesel tractor is running??????? The ones I've looked at dribble fuel from the fuel return line into the tank neck similar to the way an elderly man relieves his bladder, positively NO SPRAYING.

 

[fritza2tt]

TX Jim, you are quibbling! Call it dribbling, call it spraying, the point is that enough fuel gets sucked into the engine this way to take over from the fuel injection pump. The fuel air mixture ready for combustion is compressed and detonates inside the engine! Diesels are not meant to run this way, it's when they "run away". When my tractor gets fixed again, I will make sure that the clamp holding the fuel return line attached to the filler neck, will get a strap to keep it attached so it can never again slide off and dribble fuel, as you call it, over the engine. Heck a fire could have started just as easily, causing the fuel tank to burst! That's why I called it a design flaw. The fuel return line should never be able to slide off from the filler neck. The first time it happened, the tractor was 30 years old. I figured it was my fault and made sure the darn hose was properly secured. Well it happened again anyway and this rime it will cost big bucks to remedy. I think every one should check that hose now and then and make sure that it will continue to stay in place.

 

[Tx Jim]

TX Jim, you are quibbling! Call it dribbling, call it spraying, the point is that enough fuel gets sucked into the engine this way to take over from the fuel injection pump.

There's a difference between quibbling and stating facts from hands on EXPERIENCE. Were you running your 2240 without the 2(two) air cleaner elements? As I stated I doubt if you have ever looked into the fuel tank filler neck of a running diesel engine. I have several times and your return diesel SPRAYING from a return line isn't happening. How long do you think a piece of rubber hose should last??? In your wildest guess why would you think JD engineers put no clamps on the fuel return line hose?? I'll help you out,because there's no real PSI on the hose or line. Look at parts key #15 in the 2nd photo. Have you stopped to think that the governor ring in the injection pump could have gone SOUTH and that's why the engine over sped???????????

 

[AGRIMAN]

I have many years under my belt also and I have never seen or heard of a broken/loose return line causing an engine to run away, mostly just makes a mess. Most of the time a runaway is caused by the rank sticking. I don’t see how the engine fan is going to atomize the fuel enough to get it to combust. It’s the air intake on a 2240 in front of the radiator?

TX Jim, What was the bust pressure on the old pencil injectors? Can’t remember.

 

[Tx Jim]

AGRIMAN
Thanks for the backup. I can't remember since I left a JD dealership as service manager in '87. I think 2750 psi but I will try to find out.

 

[RickB]

Funny how many "design flaws" crop up after 30 or more years. The first time the hose came off it was an accident and or a failed part. The second time it was due to an inadequate repair and inattentiveness on the part of the owner.
How about a little preventative maintenence including the replacement of dry, checked and failing hoses?
Sounds like the OP is going to Band Aid the engine repair and likely grenade it again if he doesn't get the injection pump checked out.

The common Stanadyne/RoosaMaster governor ring failure does not cause increased return flow; more commonly return flow is reduced due to debris blocking the return line check valve. I'm certain TX Jim knows this, I'm simply expanding on his thought.

 

[fritza2tt]

OOPS, good arguments. It worked for 30 years, therefore nothing was wrong with the design of the tractor engine. You have a point. Big problem is, I am now being told that the fuel injection pump must have been at fault. Injecting more fuel would not cause engine knock! But mixing fuel with the air as it is drawn in will do it and that is what happened. Additional fuel mixed in with the air as it is sucked in by the engine, is compressed as the pistons travel up and will detonate (ping/knock) when the pressure gets high enough. If allowed to continue it will destroy the engine. In my first encounter, when the engine began to knock I reduced power and stepped on the clutch to unload the engine. And that was when the engine "ran away". I later discovered that the fuel return line connection at the tank filler neck had separated. After I reconnected the fuel return line the tractor ran normally again for years. The injection pump had nothing to do with it. The second time the fuel return line had slipped off again also. We reconnected it and the tractor started normally, albeit this time banging loudly inside the engine. I shut it down immediately. It was too late. I think the engine has thrown a connecting rod and has destroyed itself this time. All right you old coots, I'm 83 and have been around engines my whole life too. I went to school and got my mechanics license over 60 years ago! I know what I am talking about and when I tell you that this fuel return line needs to have kept an eye on, believe it. What's more, we need to tell everybody. When you have an engine running-away, if it is caused by an external supply of fuel, it will anounce itself by pinging first. (Injected fuel is timed to prevent detonation and pinging.) When you hear a diesel engine ping, do not unload the engine by pressing down on the clutch or putting the transmission into neutral. Throttle back, stay in gear, the tractor will slow down and the engine will stall. Now you will have time to investigate why the engine was pinging and you can take your time to fix what was wrong.

 

[kuboman]

I have to say fritza2tt is correct. Whether or not the fuel gets atomized makes no difference to this situation. Any fuel dumped in the intake will cause a possible runaway. Because it is not atomized is part of the reason it did not take off even under load, but it will still cause a uncontrolled burn and as the load is reduced the extra fuel is enough to let it over speed.

 

[AGRIMAN]

OK.....

 

[kuboman]

Just aside here. Ford used for many years a cold start aid on their diesels which consisted of injecting into the intake a small amount of heated diesel. Worked not to bad but not as good as glow plugs.

 

[Tx Jim]

Just aside here. Ford used for many years a cold start aid on their diesels which consisted of injecting into the intake a small amount of heated diesel. Worked not to bad but not as good as glow plugs.

JD had something similar on the 1010/2010 diesels. It consisted of a handpump on the dash that one pumped raw fuel in the the intake manifold before trying to start engine. Some farmers ibn West Texas incorporated the same idea on 4010/4020.s by teeing into fuel supply line between lift pump & inj pump with a petcock and a line attached to intake manifold. Open petcock,pump lift pump handle a few times,close petcock and start tractor.

 

[Tx Jim]

fritza2tt[/quote]In my first encounter, when the engine began to knock I reduced power and stepped on the clutch to unload the engine. And that was when the engine "ran away". I later discovered that the fuel return line connection at the tank filler neck had separated.[/quote}

So If I'm understanding you correctly you reconnected the return line hose at the tank but didn't remove the diesel soaked air cleaner elements and engine immediately ran fine?????????

If your tractor(one out of 1000's of JD utility models built) did as you state I think that would not constitute a "design flaw"

 

[Tx Jim]

The common Stanadyne/RoosaMaster governor ring failure does not cause increased return flow; more commonly return flow is reduced due to debris blocking the return line check valve. I'm certain TX Jim knows this, I'm simply expanding on his thought.

Rick
Governor ring failure causes loss of speed control and over-speeding engine. Please explain your statement?? On all Stanadyne/RoosaMaster inj pumps I've worked on that the check valve was plugged the inj pump stopped pumping fuel to injectors because the pressure was too high inside the pump case. Therefore if check valve is plugged how would that increase pressure in return line. I've knocked the check valve out in the field and reattached line and cranked the engine. On Fritz's tractor that couldn't been the problem or the engine wouldn't have run at all.

 

[Gary Fowler]

I watched my Dad deal with a busted governor ring in the injector pump on a D17 AC once when it ran away. When the OP says overspeed maybe he didnt get governor failure. The D17 was pulling a 14 foot disc in 3rd gear (it had only 4) and when the pump went wild the engine went wild. It was pulling that disc at least 25 mph down thru the field while Dad was trying to hold on and close the fuel shut off valve. I think the only reason it didnt blow the engine was because it had just been overhauled. That engine must have been turning 6000 RPM.
I dont think Fritz's tractor suffered governor ring failure if it died when he throttled back. It still may be something with the injector pump causing the overpressure on the return line though.

 

[RickB]

Rick
Governor ring failure causes loss of speed control and over-speeding engine. Please explain your statement?? On all Stanadyne/RoosaMaster inj pumps I've worked on that the check valve was plugged the inj pump stopped pumping fuel to injectors because the pressure was too high inside the pump case. Therefore if check valve is plugged how would that increase pressure in return line. I've knocked the check valve out in the field and reattached line and cranked the engine. On Fritz's tractor that couldn't been the problem or the engine wouldn't have run at all.

My bad, you are correct. My error was in mentioning an overspeed condition, I didn't claim a failed governor ring as I have experienced would caused increased return flow or pressure. I agree that a failed governor ring does not match the posted symptoms, but the injector pump could certainly have another fault that should be investigated.