# Farmtrac 390 HST fuel leak at injectors fuel rail



## bcribb52 (Apr 4, 2017)

I just replaced the injectors in my farmtrac tractor. It has the 4 cylinder Mitsubishi engine. The leak seems to be coming from around the aluminum washer (my guess) under the nut that holds the fuel rail down. My question is , how tight is that nut above the aluminum washer supposed to be and is there a certain way that the aluminum washer goes on. I can add a pic later if it will help.. Thanks


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## Guest (Jul 20, 2018)

Hello bcribb52, I'd go ahead and add the pic. It may get you a more detailed response. Thanks


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## bcribb52 (Apr 4, 2017)




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## sixbales (May 18, 2011)

Can you put an arrow (or a pen/pencil) pointing to where you think it is leaking? I see droplets concentrated at the top of the picture. You have high pressure injection lines going from the injection pump to the injectors, a low pressure return line from the injectors normally back to the fuel tank.


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## thepumpguysc (Jan 25, 2015)

By the description its the RETURN lines leaking.. the nuts tighten on the gasket..
To be honest, I've never torqued one.. just tighten it up, check for leaks & off ya go.
Did you REPLACE the gaskets or are they the old ones.. Those things are a 1 & done gasket.. they MUST BE replaced each time..
You "could" grind down a wrench & keep snugging them up..
OH!!! I see.. you have the gasket on the wrong side of the nut..
The gasket goes UNDER the rail & the nut seals ON TOP.. DANG.. ALMOST miss that one.. I'm still #1..Lol


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## bcribb52 (Apr 4, 2017)

sixbales said:


> Can you put an arrow (or a pen/pencil) pointing to where you think it is leaking? I see droplets concentrated at the top of the picture. You have high pressure injection lines going from the injection pump to the injectors, a low pressure return line from the injectors normally back to the fuel tank.


Its leaking fuel around each fitting at the injector. Its hard to tell if the fittings are leaking or the aluminum washer seal


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## bcribb52 (Apr 4, 2017)

thepumpguysc said:


> By the description its the RETURN lines leaking.. the nuts tighten on the gasket..
> To be honest, I've never torqued one.. just tighten it up, check for leaks & off ya go.
> Did you REPLACE the gaskets or are they the old ones.. Those things are a 1 & done gasket.. they MUST BE replaced each time..
> You "could" grind down a wrench & keep snugging them up..
> ...


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## bcribb52 (Apr 4, 2017)

I installed new gaskets and looked at my book on where the washer goes. Maybe my book is wrong. Kinda confused right now lol. 2 is the washer


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## thepumpguysc (Jan 25, 2015)

Books wrong.. look at the gasket, it has holes in it.. it seals ON the injector, then the rail, then the nut.


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## bcribb52 (Apr 4, 2017)

thepumpguysc said:


> Books wrong.. look at the gasket, it has holes in it.. it seals ON the injector, then the rail, then the nut.


I surely thank you for that information! This has been driving me nuts. Apparently its been wrong the whole time. New washers coming in next week. Maybe that part will be fixed..
Then i'll post my fuel shut off solenoid problem!!!


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## thepumpguysc (Jan 25, 2015)

I just hope you didn't tighten the nuts up to the point it distorted the line.??
Heres hoping for the best..
Ya might wanna make a "side note" in the book for future reff..
BTW> WHY did you change the injectors?? Did you get "new" ones or reman? What was the cost? about 100.00 a piece?
Does your sol. have 2 wires or 3??
Feel free to click on my name & "start a conversation"..
Post a pic of the solenoid before we start..Lol


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## bcribb52 (Apr 4, 2017)

thepumpguysc said:


> I just hope you didn't tighten the nuts up to the point it distorted the line.??
> Heres hoping for the best..
> Ya might wanna make a "side note" in the book for future reff..
> BTW> WHY did you change the injectors?? Did you get "new" ones or reman? What was the cost? about 100.00 a piece?
> ...


I had the injectors rebuilt. Was having cranking issues. But all along I think it was the fuel shutoff solenoid not energizing to let the fuel through. I took the solenoid off and the tractor fired right up. Had to push the pin inside the pump to shut it back off. The solenoid works intermittently. I just bought a start relay but havd not found where the old one is yet. Have the dash out and see the other relays but not the start relay. Must be hid somewhere lol.


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## thepumpguysc (Jan 25, 2015)

All of those "screw-in" solenoids have a very hi tendency to fill w/ oil & not work properly. I don't know if its from age, to where the bushing/housing gets worn & allows the oil to enter or what..?? but its a BIG complaint from folks..
That solenoid has 2 diff. electrical circuits.. 1 is "start" & the other is "run"..
The start is a very hi amp "pull-in".. Then it switches over to a low amp, "run" or "hold" circuit.. accomplished thru relays..
Its VERY possible for the sol. to "lose" an internal coil.. either a pull-in or hold coil.
Usually its the "pull-in" that goes bad, due to the amp draw..
The "EASIEST" & least expensive thing to do is check the relays {google how} or replace them.
I say, "easiest" w/ tongue in cheek.. Def. less expensive tho.
The Black wire is your GROUND.
The White wire is Pull-In or start.
& Red is Run or Hold.
You can check the coil w/ alligator clips straight off your battery..
You'll have to apply slight pressure to the plunger to get it to work.
Good luck.. & let us know how it goes.. TPG


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## bcribb52 (Apr 4, 2017)

Got the injector part fixed thanks to you!! I really appreciate that help! 
Now i cant get the fuel shut off solenoid to work. Ive bought a start relay but I cant find where it plugs in. The solenoid wiring seems complicated. I hooked a wire from the starter that only has power when the key is turned to the crank position to the pull wire on the solenoid. As soon as I turn the key to the on position the starter energizes. Hooked to the white wire is when this happens. Theres 4 solenoids under the dash. Flasher, glow timer, HST relay not sure what that is and one that dont havd a part number.


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## bcribb52 (Apr 4, 2017)

thepumpguysc said:


> All of those "screw-in" solenoids have a very hi tendency to fill w/ oil & not work properly. I don't know if its from age, to where the bushing/housing gets worn & allows the oil to enter or what..?? but its a BIG complaint from folks..
> That solenoid has 2 diff. electrical circuits.. 1 is "start" & the other is "run"..
> The start is a very hi amp "pull-in".. Then it switches over to a low amp, "run" or "hold" circuit.. accomplished thru relays..
> Its VERY possible for the sol. to "lose" an internal coil.. either a pull-in or hold coil.
> ...





thepumpguysc said:


> Books wrong.. look at the gasket, it has holes in it.. it seals ON the injector, then the rail, then the nut.


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## bcribb52 (Apr 4, 2017)

You were so right about the book being wrong. I put the washers on like you said and all leaks have stopped and the tractor is running good. I still have to get this fuel shut off solenoid working and i'll be good. Thanks for all your help..


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## thepumpguysc (Jan 25, 2015)

Glad it worked out.. I was working on a New Holland w/ the same set-up today & was thinkin about you.. Sorry but I'm no help on the starting circuit.. I do know that the HST relay is for the transmission.
If you go to TBN {tractor by net} & become a member..They'll know.. Good luck.


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## thepumpguysc (Jan 25, 2015)

I forgot to mention.. while I was working on/helping the customer, install his pump & injectors, I mentioned THIS thread about putting the washers on the wrong side..
He stopped for a second & said, "I saw that thread".!! "Where the book was wrong"??
I said, "Yes, that was it".. He said, "YOUR the Pump Guy"?? I said, "yup".. He said "Holy Sh*t!!!! NICE to meet you.. I read your posts ALL THE TIME..
Its kinda nice to meet a fan..Lol


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## bcribb52 (Apr 4, 2017)

That's pretty cool how you met this guy and glad people are reading these post. Hopefully farm trac didn't go out of business because of the way their repair manual was so screwed up.. Again thanks for your help...


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## thepumpguysc (Jan 25, 2015)

Your welcome.. Farmtrac isn't the ONLY ONE..
The makers of the pump & injectors are guilty of it too.. {yours is Zexel}..
If you look at a Bosch diagram of a lift pump.. it shows the MAIN pumping valve on the parts break down, going in the wrong way..
You know what happens when you put it in wrong?? it wont pump.. So you end up buying a 200.00 lift pump because the diagram in the 15.00 kit is wrong..
I have strong ties w/ the factory & mentioned THAT.. They said, and I quote>>
"we know".. I guess they're making so much money off of that little "mis-print" that they wont change it.. even after it was brought to they're attention..??
Did you go join TBN?? I hope you get your shut off problem straightened out.. Good luck..TPG


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## bcribb52 (Apr 4, 2017)

thepumpguysc said:


> Your welcome.. Farmtrac isn't the ONLY ONE..
> The makers of the pump & injectors are guilty of it too.. {yours is Zexel}..
> If you look at a Bosch diagram of a lift pump.. it shows the MAIN pumping valve on the parts break down, going in the wrong way..
> You know what happens when you put it in wrong?? it wont pump.. So you end up buying a 200.00 lift pump because the diagram in the 15.00 kit is wrong..
> ...


Yes I did join and got some good feed back. I found the start relay finally and changed it out but also had to fix some wiring issues. Seems to be doing good at the moment. Thanks for your help and advice.. BArry


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## bcribb52 (Apr 4, 2017)

thepumpguysc said:


> Your welcome.. Farmtrac isn't the ONLY ONE..
> The makers of the pump & injectors are guilty of it too.. {yours is Zexel}..
> If you look at a Bosch diagram of a lift pump.. it shows the MAIN pumping valve on the parts break down, going in the wrong way..
> You know what happens when you put it in wrong?? it wont pump.. So you end up buying a 200.00 lift pump because the diagram in the 15.00 kit is wrong..
> ...


When my solenoid is out of the pump my tractor fires right up. When I put it in it takes longer for the tractor to crank and thats after I hear the solenoid kick in.It seems like its still too close to the shut off lever and its only screwed in a couple of threads.. Is there an adjustment i'm missing on the pump besides screwing the solenoid in or out?


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## thepumpguysc (Jan 25, 2015)

No.. I wonder if the control rack in the pump is sticking??
You can unscrew/remove the sol. & reach in w/ your finger or small screwdriver & push on the pump rack.. it should immediately respond when you let it go..


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## thepumpguysc (Jan 25, 2015)

I was working on 1 the other day..not a FT but similar.. it had a screw in sol. like yours.
I was diagnosing a "no start" problem & removed/unscrewed the solenoid..
Once I got it started, I screwed it back in.. I screwed & screwed & screwed.. I didn't think it was ever gonna shut off.!!
It wasn't until about the last 2 threads until it died.. & I stopped & tightened down the nut.. I hooked up the electr. connector & started & stopped the engine about 10x.. it worked flawlessly..
SO. thinking about your problem.. unhook the connector..remove the sol.. start the engine & screw it in until the motor dies & lock it down.. NOW try to start it..& see if its any better.. Good luck.


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## bcribb52 (Apr 4, 2017)

thepumpguysc said:


> No.. I wonder if the control rack in the pump is sticking??
> You can unscrew/remove the sol. & reach in w/ your finger or small screwdriver & push on the pump rack.. it should immediately respond when you let it go..


I can push on the pump rack and it will shut down. With the solenoid in it seems like I don't have as much power. The tractor bogs down under a small load like its not getting enough fuel.. If I leave the solenoid out it blows out oil. The solenoid is working now bit I don't have the power under load like I use to have. Seems like something in the pump needs adjusting?


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## thepumpguysc (Jan 25, 2015)

That's not what I asked.. the rack should come back after you pushed it in.. IF NOT, its sticking..
Turn the engine off.. take out the sol. , push on the rack w/ your finger & let go.. does it come back?? ALL THE WAY?? It should be smooth..


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## bcribb52 (Apr 4, 2017)

thepumpguysc said:


> That's not what I asked.. the rack should come back after you pushed it in.. IF NOT, its sticking..
> Turn the engine off.. take out the sol. , push on the rack w/ your finger & let go.. does it come back?? ALL THE WAY?? It should be smooth..


Ok. Solenoid out. Engine running. Pushed on rack and shut down. All working smoothly


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## thepumpguysc (Jan 25, 2015)

OK.. we're gonna try this just 1 more time..
LOOK AT 1st 4 words in the 3rd sentence.. TURN THE ENGINE OFF..
..TAKE OUT THE SOLENOID.. PUSH ON THE RACK.. IT SHOULD FOLLOW YOUR FINGER BACK.. ALL THE WAY BACK.. 
I would do this on a COLD engine.. leave the solenoid out, the next morning come out & push on the rack & see if it responds.. FULL TRAVEL..


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## bcribb52 (Apr 4, 2017)

thepumpguysc said:


> OK.. we're gonna try this just 1 more time..
> LOOK AT 1st 4 words in the 3rd sentence.. TURN THE ENGINE OFF..
> ..TAKE OUT THE SOLENOID.. PUSH ON THE RACK.. IT SHOULD FOLLOW YOUR FINGER BACK.. ALL THE WAY BACK..
> I would do this on a COLD engine.. leave the solenoid out, the next morning come out & push on the rack & see if it responds.. FULL TRAVEL..


Sorry for the late response. I went another route on fixing the solenoid intermittent problem. It apparently goes through a couple of relays and the starter system. It didn't ever seem to get enough voltage to pull the relay in when starting the tractor. I hooked up a momentary switch from a 12 volt source to the solenoid pull wire. I can activate the solenoid with this switch after I hear my glow plug relay kick out and then start the engine. The momentary switch won't stay on so the pull wire only has power for a second or two. The hold wire keeps the solenoid pulled in while the tractor is running. Turn the key off and the tractor shuts down. Its just one extra step I have to do on starting and its safe and it works every time. My tractor is running great! Thanks for all of your responses and help for getting my injector leaks solved and this tractor up and running again..


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