GC1705 loosing it's prime.

[atsah]

My buddy bought a GC1705, he asked me to check it out because I have one, the tractor starts great when it's hot, when the engine sets for an hour in 80F temps it acts like it's not getting fuel, it starts but cranks for a while. The glow time or plugging the block heater in makes no difference.

It has a new fuel filter and gasket, it has good fuel in it, I loosened the banjo bolt on the injector pump and turned the key and the fuel pump is working fine. I don't understand why it seems to loose it's prime. All hoses and clamps seem to be fine. The only thing I can think of is maybe he has an injector pump leak somewhere and it's sucking air but I see no fuel leaks throughout the whole tractor.

Is there anything I'm missing here, I know some about how it works but I'm sure there are people here that know a lot more. I assume the return line is there so that warm fuel goes back into the feed line so that it doesn't freeze.

Any help would be appreciated..

 

[thepumpguysc]

IF it shuts off w/ the key switch, it has an electric s/off solenoid on it..
THATS probably the culprit.. seeing you determined it has fuel AT the inj. pump inlet..
Just remove it to diagnose the problem..
IF it has a manual pull cable, the control rack in the inj. pump, is probably sticking.
Let us know..

 

[atsah]

IF it shuts off w/ the key switch, it has an electric s/off solenoid on it..
THATS probably the culprit.. seeing you determined it has fuel AT the inj. pump inlet..
Just remove it to diagnose the problem..
IF it has a manual pull cable, the control rack in the inj. pump, is probably sticking.
Let us know..

If what shuts off with the key switch? Can you explain in a little more detail, I don't know a lot about what I'm looking at. When you say manual pull cable are you talking about the throttle bolted to the injection pump?

If the rack is sticking the tractor would start and run okay with a warm engine?

This solenoid you speak of, what is it痴 function?

 

[DMW]

This is the fuel shut off solenoid I believe PumpGuy is talking about. The MF1705 has an electrical solenoid that stops the fuel flow when the key switch is turned off. It is located on the driver's left side of the engine. It can also be used as a way to stop the tractor if the fuse for the solenoid blows. There is a rubber cap on the end that can be depressed to stop fuel flow. If the solenoid is stuck in the closed position there will be no flow from the pump to the injectors.

Also just double check that the fuel shutoff valve beside the filter is fully open.
http://www.tractorbynet.com/forums/...-not-cut-off-gc2300-fuel-shutoff-solenoid-jpg

 

[Eagleview]

Try loosening the fuel cap . The tank vent might be blocked and causing a vacuum to form in the tank .
The contracting Diesel caused by the cold can create a vacuum in the tank if the vent is blocked . Ever seen a Plastic Jerry Can when it has been left out in the cold ?

 

[thepumpguysc]

If THE ENGINE shuts off w/ the key switch or do you have to PULL A CABLE to get the ENGINE to SHUT OFF..
The electric SHUT OFF SOLENOIDs have a tendency to fill with oil & stick at start up.. Simply remove the solenoid BEFORE STARTING the engine for the 1st time & see if it starts right up..
OR have SOMEONE ELSE do it..

 

[atsah]

Thanks to all you guys for helping. I will check to see what happens today when I do all of the above and report back this evening. I kinda knew that solenoid was for shutting it off manually but I didn't know it could fill with fuel. I did think of the tank cap, I loosened it the other day and it didn't seem to help.

 

[atsah]

Okay so I just unplugged the solenoid and tried starting it, it cranked for a while like before. I plugged it back in to shut it off, after the tractor was shut down I pushed the rod inside the rubber boot several times and it started immediately, I'll try it again after it cools for a bit.

 

[atsah]

So I just went out, and gave it 7 seconds of glow plugs and it started immediately, What did I do to make that solenoid work? Maybe I needed to shut the tractor down with it for it to not stick? I don't know.. If that's the case maybe manually shutting the tractor down once in a while is a good idea?

Left it for a few more hours, gave it 7 seconds on the glow plugs and it started perfectly. Keep in mind this has been a problem since he bought the tractor as a leftover a year ago.

I'm wondering if the gasket needs replacing or I should leave it alone?

When he left it here the other day, after I shut the tractor off I noticed a click noise about five seconds later coming from that solenoid area that I don't hear from my tractor, Now I don't hear it on his either, I'm wondering if it being stuck was the cause of the noise as well.

Is this going to be an issue in a month from now? Do I need to replace it or leave it alone since it's working like it should?

 

[DMW]

You could try this to see if the solenoid is working. Leave the tractor in "gear" so it won't crank over. Turn the ignition switch to start (but it won't crank over because of the interlock). Turn the key off and you should hear the click from the solenoid. Every time you turn the ignition on/off, it should click. Several seconds after turning off you should also hear a click (my GC2300 is 8-10 seconds). Is it possible that a relay isn't working properly for the shutdown? The parts are too expensive to just replace en masse. thepumpguysc seems very knowledgeable, maybe he can recommend a methodical way of testing each component.

 

[atsah]

You could try this to see if the solenoid is working. Leave the tractor in "gear" so it won't crank over. Turn the ignition switch to start (but it won't crank over because of the interlock). Turn the key off and you should hear the click from the solenoid. Every time you turn the ignition on/off, it should click. Several seconds after turning off you should also hear a click (my GC2300 is 8-10 seconds). Is it possible that a relay isn't working properly for the shutdown? The parts are too expensive to just replace en masse. thepumpguysc seems very knowledgeable, maybe he can recommend a methodical way of testing each component.

I just went out and tried what you told me to try, I heard both clicks you speak of. I am wondering if I somehow reset that replay during my diagnostic work today? Could be that is what wasn't working. I wish I knew where it was located to make sure the contacts look good.

 

[DMW]

The parts book lists the relay on the same page as the solenoid, but gives no description of its operation. 3710474M1 RELAY.
It is located under the dash on the left side.A black 2"x2" box. I have no idea how to test it, except by removing a battery cable if the tractor doesn't start. The solenoid has to be energized to shut the tractor off. With no power, and if the solenoid is moving freely you would hear the click when it shifts open. I am making an assumption that the relay is a timer for the solenoid, I could very well be wrong.



When you removed the solenoid was there any corrosion that could bind the operation of the rod?

 

[atsah]

I didn稚 remove it, I unplugged it.

 

[DMW]

Is the tractor still under warranty?

 

[atsah]

No, it痴 working perfectly now I would just like to know what made it work, all I did was disconnect the solenoid, started it, plugged the solenoid back in while it was running, turned the key off and pushed the manual shutdown inside the boot and it痴 been working ever since.

 

[atsah]

I知 thinking the solenoid shaft was stuck, I would like to remove it and look at the shaft, if I do is there fluid going to come out when I remove the two bolts? I would probably have to install a new gasket if I do remove it.

At this point I have to agree with pumpguy, I think the shaft was stuck.

I really appreciate the help, I was at a loss.

 

[DMW]

My best untrained guess, corrosion/deformation on the rod causing binding in the pump. When warm, the hole in the pump slightly expands from the heat allowing it to operate freely when warm. When cold, there is enough friction to make it stick. When you moved it manually, it may have been cleaned up enough to operate freely when cold. If it happens again I would get a new gasket, remove the solenoid and ensure it is clean. Its not something that is common on the GCs.

 

[atsah]

That makes sense to me, am I going to lose fluid when I take it off?

I just replaced the battery for him, it was very weak, I wonder if sending less than 12 volts to the solenoid for a long period of time made the shaft get stuck.

 

[WranglerX]

Think DMW may have nailed it...

Could be it just needs a bit of cleaning, maybe remove boot, look to see if easily disassembled and cleaned, reassemble keep fingers crossed... IF you have reasonable mechanical skills you might fix it, if not worst thing is you can do is ruin it and have to replace it.... But sounds you may be on right track to locate problem...At least keep testing for now..

Engine stop relay (#28 in wiring diagram) seems to be single pole single throw normally open relay (by electrical diagram in manual).. And seems to control the fuel shut off solenoid...Key on, relay should operate causing fuel solenoid to operate...

Dale

 

[thepumpguysc]

You will NOT lose any fluid if you remove it..
BUT if its working> leave it alone.. atleast you know where the problem probably is, if it happens again..
Its possible the connectors were alittle corroded & unplugging & plugging it back in, cleaned the terminals??
OR the battery was weak.. it takes ALOT of juice to snap that sol. closed..
OR it was full of oil..
Either way.. leave it alone.. just my .02..
Happy tractoring..