John Deere 445 sputtering when warm

[BigdBaker]

I致e got a 445 EFI Deere with about 1100 hrs on a rebuild. After mowing for 20-30 min it starts to surge and sputter. First I changed fuel filter, no difference (surprise!). The dealer suggested maybe coils getting heat soaked or fuel pump. I ran it until it sputtered again and pulled off each plug wire while running. Both coils putting out spark. I then pulled the fuel pump and checked screen and changed the rubber hose that connects it to the sending unit (another forum states that as a common problem) still no difference. Last thing I tried was I pulled the air filter and ran it while cold so I could see the fuel spray from the injector. Seemed to sputter a little than as well so I sprayed it with cleaner and it got better. Now I noticed oil seeping out of air cleaner base into throttle body while running as well??!! Please help, I'm about to lose my mind on this thing!

 

[beenthere]

:welcome: to TBN
I'm interested in what you find out from your post. My son bought my 445 and so far, haven't heard of any similar problem. But will follow along with you.

What caused the re-build?

 

[BigdBaker]

I bought it used about 2 years and 100 hrs ago from a friend whos brother works at a Deere dealer. Apparently it got traded in on a new one so the dealer sold it to him for what they had in it. Head gasket, cam gear and other things so he did a rebuild. I really like the machine.

 

[BigdBaker]

Also isnt thr 455 diesel?

 

[beenthere]

??
My 455 is diesel, but my old 445 is owned by my son now. Still interested in what may be going on with your 445. As well, my X485 is much the same as your 445.

 

[BBO]

It seems the 445 EFI is a complicated machine and not so easy to work on.
Could the valve need adjusting?
That oil is a problem for mine also. I had new rings installed, and that crankcase vent still spits oil up in the air filter assy.
If you have not changed the plugs yet do that first.