1988 john deere 510c project

[Delmer]

Yes, the unloader/destroke could cause intermittent harder starting. Wiggle the steering wheel as in post #9 to determine if the hydraulic pump is not destroking and causing the hard cranking.

You could have multiple problems going on, could be all electrical related, or could be a fuel issue along with mechanical starter issues.

Hard starting is tough to figure out with all you have going on, go back through the suggestions and tell us what's been done and what's not been done.

The stalling after running is easier, either you're running out of fuel because of the blockages that you know you had, and are probably still dealing with. Or you're losing voltage to the injection pump, or the injection pump solenoid is failing. Most likely you have garbage in the tank plugging filters again, combined with possible cracked hoses. Fix that first, then worry about the electrical if it still stalls with a clean fuel system. One way to diagnose the stalling is to add a LED light on the dash fed back from the injection pump terminal, so the light confirms power to the injection pump, and/or a fuel pressure gauge teed into the supply to the injection pump and run to the dash so you can see how the fuel pressure holds up under load, and have warning before a stall. Neither of these is needed if you clean the fuel system and it stops stalling.

 

[Fedora]

Thanks guys I'll let you know how it goes. I did order a new starter . Do you think the hot ground cable could simply be caused by the starter? It continues to turn even when the key is out and eventually it stops. I have the 2 book technical manuals but there isn't any wiring diagrams in it.

 

[Tinkerer]

Thanks guys I'll let you know how it goes. I did order a new starter . Do you think the hot ground cable could simply be caused by the starter? It continues to turn even when the key is out and eventually it stops. I have the 2 book technical manuals but there isn't any wiring diagrams in it.

Better get a new starter (ignition) switch before you destroy that new starter.
There is a chance that it isn't the switch causing the run-on with the starter. It can be a fault in the wires or wire routing.
I think installing a main disconnect switch on the battery cable will give you the capability to instantly cut the power to the starter in case it does run-on after releasing the key in the ignition switch.
I once made the mistake of buying a cheap ass switch on ebay and it stuck in the start position and destroyed my starting motor.
Not from heat but the centrifugal force from the motor spinning it.

 

[Delmer]

There's nothing complicated about any of the wiring. If you don't have voltage to the small wire on the starter, and the starter stays engaged, then you have a mechanical problem with the starter. If you do have voltage to the small wire on the starter after the key is released from "start", then you have an electrical problem.

If the starter will crank the engine for 20 seconds and not warm up any of the connections, then I'd guess your cables are fine. Usually it's the ends that get corroded. Unless the cable breaks midway, then it will be super flexible in that spot.

 

[Tinkerer]

For the safety of your new starter, remove the all the small wires from the solenoid.
After doing that run a new wire from the start position on the starter switch the terminal on the solenoid that engages the starter.
Then after you start the engine put a volt meter on each of those dis-connected wires and look for one of them to have a voltage reading.
I am guessing one of them will have current in it, and that would be the reason for the starter not shutting off.

 

[Fedora]

Wonderful suggestions guys. The starter is going to take a few weeks to arrive and I'll follow up afterward. I already ran a new #10 wire from the key ST to the small post on the solenoid , so I know it's good. I also ran a new wire from the injection pump.

 

[Fedora]

Well my little black cloud continues to keep watch over me. The starter arrived and it was just tooo hot to go out and work on it 90 F , Went out yesterday as it was suppose to be a little cooler but damn the temperature dropped to 44 F with winds and rain that made it miserable. I took the old starter off like an expert now that i've done it 5 or 6 times and upon inspection it is definitely fried. Opened the new box and....see pic , now back to ebay to try and get the right one. Oh well, guess it will warm up again.

 

[Fedora]

Happy Father's day! Starter on , fired her up ... Worked wonderfully. Then when I tried to shut off it continued to run. Guess it didn't want to quit yet, lol. I pulled the fuse to the fuel and it stopped. I can start it no problem. I tried just pulling that fuse without turning the key off and it continues to run until I turn the key off.

 

[Delmer]

I'm not going back through four pages to see if anything was mentioned about the alternator.

I'd suspect the alternator is hooked up wrong, or there's not the right diode or resistor in the alternator excite circuit, that should solve the turning off issue.

 

[Fedora]

I'm not going back through four pages to see if anything was mentioned about the alternator.

I'd suspect the alternator is hooked up wrong, or there's not the right diode or resistor in the alternator excite circuit, that should solve the turning off issue.

I don't blame you for not going back 4 pages. I wouldn't either. i really appreciate your help and Tinkerer and others as this sure has been a learning experience for me. When I bought this machine, I noted that the previous owner had installed a new alternator. I'm pretty certain the issue is in the wiring. In any event yahoo i think I've turned a corner on its issues. Thank you.