This 9100 Ran Away at 3,000 RPM...Then Turned Into a No-Start Nightmare

This is the full story of Greta — a John Deere 9100 that would not start, or sometimes run away, or start and die. This job didn’t happen all at once. It was spread across multiple service calls, multiple trips, and a whole lot of diagnostics trying to track down the issue. Instead of leaving it scattered across several videos, I wanted to bring everything together into one complete story so you can see exactly what it took to get this tractor figured out. What started as a simple no-start quickly turned into a deep dive into wiring, fuel system diagnostics, and eliminating problem after problem until there was only one answer left. These are the jobs that test you — where everything should work, but doesn’t… and you have to stay with it until you find the truth. In this video, I walk you through the entire process — the testing, the setbacks, and finally getting Greta running again. ⏱️ CHAPTERS 00:00 Intro 02:12 Electrical Testing / Running New Wires to Pump 04:06 Testing After New Wires 06:14 Using Old Pump to Clear Codes 08:15 Trying to Start After Codes Cleared 10:01 Looking Inside the Pump 11:01 Removing the Fuel Pump 13:24 Pump Back From Pump Shop 13:45 Installing the Pump 14:14 Trying to Start After New Wiring Harness in Pump 16:25 IT’S RUNNING AGAIN! 19:03 What Do We Do Next? 20:29 Testing Fuel Injectors 21:54 Installing Another New Pump 22:58 Everything Eliminated… Except ECU 25:33 ECU Programming – Hail Mary 27:08 IT’S ALIVE!!! 28:38 Diagnosis / Repair Recap 29:40 Outro – Goodbye Greta Want to see the best of ZK MasterTech? Check out my top repair and service videos here:    • Best of ZK MasterTech!   Follow me on TikTok! official_zkmastertech https://www.tiktok.com/@official_zkma... Follow me on Instagram @zk_mastertech Want some ZK merch? https://zk-mastertech.myspreadshop.com/ Check out my Amazon store front! https://www.amazon.com/shop/zkmastertech Want a career with Sloan Implement? https://www.sloans.com/career Thanks to Sloan Implement and John Deere for their continued support. Subscribe for more in-depth diagnostics and field fixes. And as always — keep that green iron moving!