JD 650 won't start

   / JD 650 won't start #1  

sporteus

Bronze Member
Joined
Oct 20, 2015
Messages
56
Location
Middlefield, CT
Tractor
John Deere 650 - Very Used!
OK, been futzing with this for too long and not getting anywhere. Need advice before I end up hiring someone .

Last year when I was using my tractor I had zero issues with it starting. first or second crank and it fired right up. Then I parked it for a couple of weeks.....and our story begins.

It would fire on the first crank and then no ignition. let it sit, lay on the thermo start for a while, and same thing, single ignition and then nothing. tried a few different times over the winter (as warm as it was) and nothing. plugged in the block heater for half a day and no change in symptoms. last time I cranked it for quite a while and finally gave up figuring I had to have a hard air blockage in one of the lines.

So today, I went through and checked/bled the lines. No air that I could tell, got fuel at the check points all the way to the injectors. Now, one of the injectors appeared to have less flow to it than the other, but there was fuel. Same symptoms, it will crank with no ignition.

(One thing to note is that I was not able to loosen one of the injector lines at the pump. I think the bloody thing was cross threaded by a previous owner and the coupler won't budge. however, there is good flow in that line at the injector, so I stopped worrying about it. )

If this were a gasoline engine I'd be checking for spark at this point.

Short of a complete fuel system tear down and rebuild (which I don't even know if I could get replacement parts for) what's my next step? I'm not a mechanic but this shouldn't be this difficult. Do I need to pull the injectors and look there? Fuel was fresh a couple of months ago with anti-gel/stabilizer added.

Advice is appreciated.
 
   / JD 650 won't start #2  
sporteus,

Please don't take offense to this because no slight is intended ... Is your throttle lever up off the home position a bit? When I picked up our used JD650 last year it took me a while to get used to bringing up the throttle lever a bit before cranking. On my 2520, and the 2305 I used to have, the preferred start spot is with the throttle all the way "home". Something easy to check ???

Frank
 
   / JD 650 won't start
  • Thread Starter
#3  
Unfortunately, nothing that simple. I have had those moments of remembering the throttle position, so I know what you mean. But this isn't one of them unfortunately. Heck, even tried closing the throttle to see if there would be any change in behavior...there wasn't, go figure. LOL.

By the way, watch your PTO lever position too. Had a panicky 15 minutes last year because my neighbor was screwing with the tractor when I had it parked and engaged the PTO. For the life of me I couldn't figure out why it wouldn't start all of a sudden after using it all morning. Safety switches, sigh. (I'm just glad there is no operating safety switch under the seat on this one, that would make me farg'n crazy.)
 
   / JD 650 won't start #5  
Barring something cantankerous such as a missing cotter pin that helps activate throttle rods, the injector pump on these things let go all of a sudden. If you haven't got inner fuel line fouling with gelling or fuel filter screen debris, I'd say pump. In warmer weather, the tractor should start without the glow plugs actuated.
If you are getting NO smoke when the engine is cranking, that would confirm a bad injection pump to me if all the simple ,obvious things have already checked out. The pumps are timed to the engine and this spec should be in your manual.. You can also loosen a line at the injector nozzle, move lever to "start," crank the engine and see if you are squirting fuel out at this point.
 
Last edited:
   / JD 650 won't start
  • Thread Starter
#6  
arrow,

I will get smoke from the stack when it fires that first time and then very limited smoke when it continues to crank. What kind of fuel pressure should I expect from the lines at the injectors? If I disconnect both lines and crank it, is it a flow of fuel or a jet of fuel that I should see out of the lines? I don't know how much pressure they push, but expect it should be relatively significant since the injectors have to vaporize the fuel.

My thinking at this point is:

1.) disconnect lines at injectors again and crank it. reconfirm fuel flow and quantity. if there is something funky with the pump, this would be an indicator. (found out last night I can't get the main injector pump parts anymore, so hoping that's not the case)
2.) something screwy with the timing on the pump. I wouldn't expect that to suddenly "go bad" but stranger things have happened. Worth confirming if I can.
3.) pull the injectors (caution me if I shouldn't do this) and inspect. (another set of parts that aren't all available)
4.) (and maybe i should start with this) pull the fuel tank and drain it. I'm sure there is moisture in the fuel, but don't expect its the root cause since these symptoms were occurring last year with fresh fueld before it sat for too long. But it could be compounding an underlying issue.

I'm still very much in the mindset that this is a fuel issues since there's not much else that could cause these symptoms in my mind. If it were getting good fuel flow, I would expect steady smoke when cranking, right?
 
   / JD 650 won't start #7  
Check with the guys down at Hoye tractor in Texas. They handle about anything you could want for these little yanmar tractors. (940) 592-0181. Also, the guys over on the yanmar forum are extremely knowledgeable on these little tractors. You might post over there for some help.
 
   / JD 650 won't start #8  
OK, been futzing with this for too long and not getting anywhere. Need advice before I end up hiring someone .

Last year when I was using my tractor I had zero issues with it starting. first or second crank and it fired right up. Then I parked it for a couple of weeks.....and our story begins.

It would fire on the first crank and then no ignition. let it sit, lay on the thermo start for a while, and same thing, single ignition and then nothing. tried a few different times over the winter (as warm as it was) and nothing. plugged in the block heater for half a day and no change in symptoms. last time I cranked it for quite a while and finally gave up figuring I had to have a hard air blockage in one of the lines.

So today, I went through and checked/bled the lines. No air that I could tell, got fuel at the check points all the way to the injectors. Now, one of the injectors appeared to have less flow to it than the other, but there was fuel. Same symptoms, it will crank with no ignition.

(One thing to note is that I was not able to loosen one of the injector lines at the pump. I think the bloody thing was cross threaded by a previous owner and the coupler won't budge. however, there is good flow in that line at the injector, so I stopped worrying about it. )

If this were a gasoline engine I'd be checking for spark at this point.

Short of a complete fuel system tear down and rebuild (which I don't even know if I could get replacement parts for) what's my next step? I'm not a mechanic but this shouldn't be this difficult. Do I need to pull the injectors and look there? Fuel was fresh a couple of months ago with anti-gel/stabilizer added.

Advice is appreciated.
Congratulations on doing a check of the fuel delivery system and trying to trouble shoot the system. Throwing parts at it is hit or miss as well as expensive. When's the last time you changed the fuel filter? Is your air filter clear? You need fuel and air to run the engine. Is your battery cranking well? How cold is it? Are you using your starting aids (glow plugs, block heater, Thermostart, etc)?

Are you seeing "white smoke" while you are cranking? That's a sign you're getting fuel and it's not igniting. If you only see a puff or two while cranking and then it quits that's a sign that you had initial fuel flow and it quit. Some times the tank strainer or the fuel filter will have a partial clog and it will let enough flow in to fill the lines while the tractor is sitting but not allow enough to start and run. If you disconnect the fuel supply to the injection pump downstream of the filter, and you don't have a lift pump, you should get a steady stream of fuel from the tank through the filter that fills the line. If it dribbles or is intermittent, then you have a restriction upstream. The tank strainer can clog, the fuel hose can split internally, crud could clog the filter head, etc.
If you are positive about fuel delivery to the pump and through to the injector lines than either the injectors aren't working properly or you have too low compression. However you did not have starting problems before and low compression doesn't just suddenly happen unless their is some mechanical damage to the piston and/or the valves. I think your issue is a fuel delivery problem. You'll just have to be patient and find it.
 
   / JD 650 won't start #9  
arrow,

What kind of fuel pressure should I expect from the lines at the injectors?

II would expect steady smoke when cranking, right?

1. It is significant
2. Yes

As JerryMT suggests: eliminate all possible line blockages first. Pumps are not cheap.
 
   / JD 650 won't start
  • Thread Starter
#10  
I'm 99% convinced it's the pump through my diagnostics. Of course you can't just buy a new replacement and pop it in, so that makes me double sure!

OK, Here's the latest (not in order of operations):

1.) dropped the bowl on the filter yesterday and discovered the bottom half of the filter had a nice ice ring on it. sigh. Pitched the filter, cleaned the bowl, primed it with fresh fuel. (I added about a gallon and a half of fresh fuel (treated) to the tank last week, but have not drained it.)
2.) pulled the reservoir off that feeds the glow plug and emptied that. primed it with fresh fuel today.
3.) confirmed good fuel flow to the injector pump and no air. (starting to create a small hazmat situation rechecking these flows!)
4.) pulled the hard lines off the injectors and cranked it. there is fuel flow, but not what I would consider pressurized. better fuel flow to front cylinder (#2, i think) than back cylinder.
5.) read the article on the hoye tractor site about the fuel pump getting "stuck" and gave it a few love taps with a hammer.
6.) plugged in the block heater overnight. She was toasty this morning.

If I lay on the thermostart, I will get an initial fire and then nothing. So, this is telling me there is insufficient flow/pressure on the mainlines to sustain the combustion, right? I also still have the issue with the #1 cylinder fuel line being "stuck" at the injector pump, so that's going to cause me grief since you can't buy that coupler piece anymore. Sigh. (hello, salvage yard? want to send me a second tractor so I can have a parts supply?)

From everything I'm reading, I think my next steps would be:
1.) get what parts I can for the injector pump. will have to get back in touch with my friends in LA to see if they have the injector pump on that 650 sitting in the salvage yard. get what I need for a rebuild or send it off to Hoye for a rebuild.
2) new hard lines for the injectors. The one that is stuck is already twisting at the coupler, so I know that's gonna be a sacrifice part.
3.) pull the injectors and have them rebuilt. Again, can get some of the parts but not all. I might just send these to Hoye and have them do the rebuild.
4.) completely drain the fuel tank and clean it. (need to find 6+ gallon container and a way to dispose of the diesel). any recommendations on tank cleaning are appreciated.
5.) Thinking I'll replace any of the soft fuel lines while I'm at it. that's easy and cheap, so what the ****.

Having gone through this with a boat I bought years ago with a tank full of **** and no fuel filter (ya, that was a nightmare), I'm kind of going for a full rebuild here, but may stop at the pump and the hard lines if that gets 'er running.

Any advice or cautions are appreciated. If I should take an alternate path or look at something else, I'm all ears.

Thank you.
Steve
 
 
Top