L5030 with erratic idle

dawoodwa · May 16, 2011

I have a L5030HTC with about 600hrs on it, one afternoon last week I was pulling my rotary mower and after about 2 hours the RPM's suddenly dived. I pushed in the clutch and flipped the PTO off when it was around 1800 RPM's but it continued it's death spiral and shut off. I have had this happen to my John Deere before and instantly assumed it was the fuel filter, so a hike to the house and back with a new filter, changed it out, and it fired right up. Started back mowing and after a few minutes it started doing it again. Never shut down with me again but the RPM's were searching up and down. Thought maybe that the vent on the tank was stopped up so I loosened the cap but that didn't help either. Made it back to the house and started looking for any leaks on the fuel system but couldn't find any.
Talked with my mechanic about the possibility of a bad injector pump but he suggested I run some Lucas fuel treatment through it first in case the fuel was not lubricating the injection pump properly.

Any ideas????????????/

bilrus61 · May 16, 2011

Sounds like it might be your air filter to me. Check it out and clean out both elements. See if that helps any. They can look clean and still be a issue. Take 'em out and tap 'em on the driveway and see how much dirt comes out.

dawoodwa · May 16, 2011

Changed both of them also, forgot to mention that when I got it back to the house I changed all the filters and engine oil.

dstig1 · May 16, 2011

Bad fuel, plugged line, crud in the lines, perhaps? Restricting fuel flow in the lines or tank would be an easy and cheap thing to check.

Did you bleed the air out of the fuel pump after changing the filter?

kuboman · May 17, 2011

You might have a bad lift pump. I would check that if it is acting like a dirty filter but not a dirty filter

texasjohn · May 17, 2011

I had some of the symptoms you describe with my L5030... key for me was that the falling RPM's then shutdown happened a few times spaced out across several days...then settled down into a stable pattern, would start and work just dandy while still... meaning that I could run up the rpm's using the throttle to the max and it would run steady.

But, trying to move would result in the engine dying...I followed various wires, discovered a loose one, it appeared to be seated, but when I removed it and reseated it the problem went away. Vexing problem, simple fix.

If you have the symptom of running fine while still and high RPM's, but not moving, let me know and I'll give you specifics of which wire fixed the problem for me.

Other than this, all prior ideas re filters, etc. are good and you've tried them to no avail.