JD 4024 wont start!

greenmojo · Dec 20, 2019

Well, I had made a mess under the generator... oil and fuel, and whatnot (it sits on a 110 gallon tank that acts as a belly pan).

So tonight I went out to clean it all since I cant do anything until tomorrow morning when the check valve arrives.

I got it all cleaned up, looking nice and then decided to try and pinch the return fuel line again and see if it would start. Plugged in the coolant heater for about 20 minutes, and tried cranking her over... after the 3rd crank and a little adjustment on the vice-grips, it STARTED!

It didnt sound perfect, you could tell there was a fuel pressure issue, and some light tuning on the Vice-grips smoothed it out a little, but enough to know it was a success!

I shut it down after about 2 minutes and look forward to the new check valve in the morning.

Woohoo!

thepumpguysc · Dec 21, 2019

Still dont know what fuel system.. but w/ the talk about the check valve I'm assuming its a RoosaMaster/Stanadyne pump..
This check valve go on top of the pump.?? if so, all u had to do is try to start it WITHOUT the check..& if it started ur on the right path.
If it starts & shuts off again w/ the new part, try taking it out & starting the machine.. its gonna make a mess unless u find a barbed fitting to screw into the top cover & run it to a bucket or back to the tank..
IF it starts & runs w/o the check.. u have larger problems..

BTW> if its the inj. pump above.. it only requires 5 psi of fuel to the inlet.

greenmojo · Dec 21, 2019

Each injector has its own pump, the check valve was at the rear of the motor as it comes out of the block.

thepumpguysc · Dec 22, 2019

Oh, OK.. gotcha.. It might just work..

greenmojo · Dec 22, 2019

We got it to fire up, but it has a terrible knock as it starts... it never had that before, so I am assuming it is still some sort of fuel or injector issue.

I am way over my head.

thepumpguysc · Dec 23, 2019

Just loosen the inj. lines 1x1 & retighten till u hear no more knock.. that'll tell u what cyl. its coming from.

greenmojo · Dec 24, 2019

The injectors are internal. I pulled the valve cover off today and looked for fuel leaking or air bubbles with the injector pumps. Can you still loosen the injector lines and check this way?

I am getting massive amounts of foam out of the return line, so air is getting in some how.

I had hot oily smelling vapor in the fuel tank, so my thoughts are that it is sucking air at one or more of the injector pumps.

Too complicated for my limited mechanical skills, so I called Pape and they are coming out in the morning to do injector pump leak kits on them.

Sure hope that is the problem!

thepumpguysc · Dec 24, 2019

Ahh, the single cyl. pumps & inj.. no, their nothing to play around with.. get someone who KNOWS what their doing..
Its SUPER EASY to bend the push rods on that engine.. if u dont follow the rules..

buickanddeere · Dec 24, 2019

New fuel poured into the tank stirred up all manner of ick, sludge, much, mud , rust and bugs in the fuel system . Drain, clean and flush the entire tank, pickup, pump lines, pump and filter body . Been there .
About a month later the mechanical low pressure fuel lift pump failed, maybe not a coincidence.

greenmojo · Dec 26, 2019

Well, different mechanic here this morning scheduled to install new o-rings on the injector pumps.

He just did not like the idea that air was being sucked into the injector pumps fuel without fuel also leaking into the oil.

He went over everything again himself and suspected that the injector nozzles might be broken and allowing combustion back into the fuel.

He opened it up, cracked the injector lines inside the head and sure enough, there was combustion coming back through a failed nozzle. Crazy!

Ordered 4 more injector nozzles and will get them installed tomorrow!

I am relieved and excited.