Oil & Fuel jd 790 will not start

[thepumpguysc]

Just remove the solenoid from the pump.. should be 2, 10mm bolts holding it on.. THEN proceed w/ your pumping diagnosis..
Loosen the lines AT THE INJECTORS, ALL OF THEM..
Crank the engine.. got fuel squirting out the lines?? YES.. the problem was the solenoid or electricals going to it..
IF NO.. reach in where the sol. goes & feel for the control rack or something to push or pull on.. cuz that's all the solenoid does..
SEE/FEEL if you can get anything to move.. if so.. crank the engine again.. GOT FUEL??

 

[gary messenger]

I had 2 blown fuses one for fuel pump and one to fuel shutoff.Replaced still wont start.removed and tested fuel shutoff solonoid.It seems to be working.Other than injector pump,what else can it be

 

[Spanner]

Let's go back to this "Fuse" thing...

You had a fuse blow 3 times and you eventually replaced it with a 20A which seems to 'work' but the circuit is low amps and as 'K7LN' advises only rates a 5A.

Now you say you have 2 different fuses blow??

And you "tested fuel shutoff solonoid" (sic) and it "seems to be working".

Can you detail just exactly what & how you tested to reach this conclusion?

Have you re-checked these 'two' fuses again?

Did you 'Search' the forum as suggested?

 

[gary messenger]

Sorry for the confusion.Originally i found 1 blown fuse,that wS to the fuel pump.Thats the one that blew 3 times and i put in the 20 (I am goinh to put right fuse back in).I later found the second fuse blown,it was to the feel shutoff solonoid.Replace that.Still wont start.Pulled the solonoid and ran wire from a battery to the pig tail.plunger pulled in stayed till i removed wire. It is leaking black oil.
was thing about taking to dealer and have the check it.
I really appreciate your help

 

[gary messenger]

Sorry for the confusion.Originally i found 1 blown fuse,that wS to the fuel pump.Thats the one that blew 3 times and i put in the 20 (I am goinh to put right fuse back in).I later found the second fuse blown,it was to the feel shutoff solonoid.Replace that.Still wont start.Pulled the solonoid and ran wire from a battery to the pig tail.plunger pulled in stayed till i removed wire. It is leaking black oil.
was thing about taking to dealer and have the check it.
I really appreciate your help

Is there supposed to be oil in the solonoid?

 

[kuboman]

Is there supposed to be oil in the solonoid?

I don't believe so.

 

[thepumpguysc]

The sol. is "cooled" by splash oil from the pumps cambox.. excess oil accumulates in it & keeps it from functioning.. factor built-in problem..

 

[Spanner]

Sorry for the confusion.Originally i found 1 blown fuse,that wS to the fuel pump.Thats the one that blew 3 times and i put in the 20 (I am goinh to put right fuse back in).I later found the second fuse blown,it was to the feel shutoff solonoid.Replace that.Still wont start.Pulled the solonoid and ran wire from a battery to the pig tail.plunger pulled in stayed till i removed wire. It is leaking black oil.
was thing about taking to dealer and have the check it.
I really appreciate your help

How many terminals in your solenoids 'Pigtail'?

There are two (2) circuits in the Fuel Solenoid. You tested the 'Pull' circuit. It "Pulled".

There is also the "Hold" circuit. There are literally hundreds of posts on here detailing 'Pull' & 'Hold'.

Reads like oil has got past the seal on the plunger pin. You can press the plunger with your finger a few times and purge the oil out as a temporary solution.

 

[sisupower]

So check the resistance on the terminals in connector. Should be 3. See pic.
As stated in Tech manual some numbers don’t match so this is what you need to see if your solenoid is good.
Fuel shutoff solenoid—
C to D ..........0.5 ohms
C to E ..........23.5 ohms
D to E ..........23.5 ohms

See what you have.

 

[Industrial Toys]

I used to have a 770, basically the same machine.

If you had a lower fuse rating that worked and now need a heavier fuse, to me, that is OBVIOUSLY your problem. Maybe shorted coils in the fuel pump.

Putting in larger fuses is a good way to start a fire!