JD 790 Sporadic Engine Stoppage - Ongoing Issue since purchase...Looking for Help!

[Homer7709]

Hello to All You "Farmers" out there! Need help! I've worn out the old internet over this deal, so I thought I had a handle on it...but have now gone thru (2) new parts and she still doesn't want to run. BTW, battery is relatively new and has been checked (ok). So, I started with the fuel solenoid - pulled it out - yes, it had some oil in it - tested it, no pin retraction - thought no problem. Amazoned one in, plugged it in - no retraction. Next component, the control module that sits behind the dash plastic. Amazoned one in, plugged her in - no retraction...now getting a little depressed over the deal! BTW, with the solenoid removed my little 790 cranks and purrs like a kitten. Turn key off, depress the little plate in the fuel pump housing, she shuts right down. I've checked wiring. The only other next in line deal I've found on the internet mentioned the key switch...that's where I'm at, hoping this post hits a nerve with someone who's been there, done that! Thanks, Homer

 

[dieselcrawler]

There was a recent thread on very similar if not the same issues... will try to find it and post a link.

Edit: http://www.tractorbynet.com/forums/...2-help-interpreting-wiring-diagram-using.html

This thread is long, but valuable information relating to your type problem. I encourage you to read it all.

We are here to help!

2nd edit: http://www.tractorbynet.com/forums/john-deere-ag-tractors/368337-790-sporadic-starting.html

First thread prior to the one above, 'part one' of the story, if you will... worth reading also.

 

[TemporaryKubotaOwnerMark]

Stop firing the parts cannon at your problem!

It's a very expensive and frustrating way to troubleshoot.

The solenoid is electrically operated. Get yourself a test light and start with the solenoid and work back to see where the electricity is NOT happening. Since you are suspecting the key switch, check to make sure power is going IN where it's expected, and if it is coming OUT where and when it is expected.

If it's coming in like it should, but it's not coming out like it should, then replace the switch.

If it's not coming in like it should, keep testing back along the circuit until you find the problem.

Also, check your grounds. Rusty grounds can cause weird stuff to happen.

Test your way to the solution.

 

[Homer7709]

Thankis DieselCrawler and TempKubotaMark! Great Information and a Good Scalding from Mark...! (but firing the parts cannon is easier...and I hate electrical stuff...!) Seriously, you are correct - I have fired up my test light and multi-meter and will get to the low down of the deal. Will keep you posted, Have a Great Day and Say Hello to the Trumpster when you have a chance! What's it like living that close to DC? Later, Homer

 

[TemporaryKubotaOwnerMark]

Any update, Homer?

By the way, what's it like living close to D.C.? Traffic, lots of traffic, and housing that's too expensive for me, so I commute an hour+ each way! :laughing:

 

[Homer7709]

Hey Mark, Sorry for late reply. Short of it is, I'm still in the workforce (with just "faint" visions of retirement...!) and we're very busy - so I haven't had a chance to get back to the troubleshooting. As soon as I do, I'll be sure to give you an update. Have a Great Day! (p.s. "I hate traffic...generally, steer clear of it every chance I get!).