newbee needs help starting model 870

You need fuel, air and heat to run an engine. So I'd start checking the cheapest and easiest items first. Do you have fuel in the tank? Is there a shut off valve that is closed? Is thew fuel filter clogged? Is there fuel after the filter? (a few months ago my diesel JD 2320 would not start. It turned out to be a mud dauber nest - made of leaves - that had completely plugged the hose at the bottom of the tank. Go figure right?)

Fuel OK? how about the air filters? Gotta have air. Does your engine have glo plugs? Are they working?

Is the key working correctly? There are several circuits activated when you turn the key on.
I'm running out of ideas. Anyone add to these?

Is there a bleed screw on the injection pump? You can crack it until fuel flows out... then loosen the fuel line on each injector. Turn it over a couple times, then re tighten the fuel lines.

BE CAREFUL! When you loosen the fuel lines at the injectors you are releasing very high pressure diesel fuel that can cut through skin, and please wear safety glasses for the same reason.

Try that and come back if you run into problems....

Just be really careful. If the injector lines are charged, or under pressure, they can squirt diesel fuel out at a pressure high enough to hurt you. If your engine is like my Yanmar engine I disconnected the fuel line after the fuel filter as it attached to the engine. It should be low pressure at this point. That is where I found on mine there wasn't any fuel coming out at all, hence the finding of the clogged fuel tank. Mine acted like your is. My wife was cutting the grass and stopped the tractor to pick something up, and then the engine just wouldn't restart.

A few other thoughts just came to mind. Does your fuel filter have a red ring at the bottom? The filter on mine is clear plastic, and at the bottom there is a floating red ring. This is the water in the fuel ring. It should be sitting on the bottom of the fuel bowl. If not you have water in the fuel.

Look at this picture. I had posted this picture once showing how to grease the U-Joint that is attached to the engine flywheel when a sharp eyed member of this forum spotted water in my fuel filter. See the red ring floating about 1 inch from the bottom?

I have pulled all the fuel lines one at a time from the filter. fuel comes out of all of them, none under pressure. pulled the line from the filter to the injector pump, fuel but no pressure. pulled return line to filter, fuel but no pressure. loosen fittings at injector pump to injector, no pressure. i have a clear filter bowl also. does not seem to have any water in it.

loosen fittings at injector pump to injector

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No fuel at the injectors while cranking?

My gut is saying check all of the circuits starting from the key. With the tractor running then not starting, I guessing something electrical. We are getting into an area I don't think I can help. Like for example, when the key is turned off, does that kill the fuel to the injectors? If so could this be the problem. Keep in mind, I am just a DIY or shade tree mechanic.

I tried the fuel line at the injectors but nothing. i did find a solenoid behind the fuel injection pump. I found out that it is a fuel shut off solenoid. It is not engaging. when i manually hold the solenoid in the tractor starts right up. There are three wires going to this solenoid. Can anyone tell me what the voltage should be on these wires. I would like to check out the voltage in the circuit before I spend $176.80 for a new solenoid if i do not need it. thanks for all of your help.

There are 3 wires-black,white and (red or pink). these wires go through the firewall and into a connnector with red wire connecting to a green wire, black wire connecting to a balck wire and the white wire connecting to a white wire with a blue stripe. i disconnected the plug and checked the voltage on the plug while turning the engine over. No voltage to any of the wires. the white wire with the blue stripe go to a module on the engine side of the firewall. The green wire and the black wire appear to go there also. I have to check this out tomorrow. I can not identify the module but it is just above the solenoid, aluminum case with a big heat sink with a black plug with 5 or 6 wires.

FHUNDLEY said:

There are 3 wires-black,white and (red or pink). these wires go through the firewall and into a connnector with red wire connecting to a green wire, black wire connecting to a balck wire and the white wire connecting to a white wire with a blue stripe. i disconnected the plug and checked the voltage on the plug while turning the engine over. No voltage to any of the wires. the white wire with the blue stripe go to a module on the engine side of the firewall. The green wire and the black wire appear to go there also. I have to check this out tomorrow. I can not identify the module but it is just above the solenoid, aluminum case with a big heat sink with a black plug with 5 or 6 wires.

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You don't need to check voltage at the fuel selenoid while the engine is cranking.... you should try to find voltage with the key on. I do not have a schematic in front of me, but look for +12V on any of the three wires to start. What interlocks are used on this tractor? Seat switch? PTO engaged? Other Safetys?

I performed a Google search for Yanmar 3 cylinder diesel fuel solenoid. Several hits describe which wires get 12 volts, when and why. I don't know if these will help or if they are even relevant, so I'll let you read them as see for your self.


I looked at my 2320 Yanmar engine and I can see the solenoid and feel it, but I would have to perform surgery on it before I could unplug the connector to test the wires.

Good Luck buddy, and let us all know what you find out. I'm curious to hear what was wrong.

I had to break down and buy a service manual. i found one that i could download off the internet less than $10.00 from tradebit.com. This is the same service manual that john deere wants $80for a hard copy. There are two coils in the fuel shut off solenoid. and three wires coming out of the solenoid. One is the pull in coil, one is the hold in coil. one wire goes to each and then there is a ground. Just behind the firewall there is a plug. The wires change colors there and go into the wiring harness. Here they go to the fuel relay and the time delay module and ground. The wire from the pull in coil to the fuel shut off relay was not making a good connnection and would not let rhe solenoid energize keeping the fuel shut off. This was a full day of tracing this down but it works. Thanks for all of your help...