JD 445 gas Kawasaki engine fouls the plug on the left cylinder

[Richard001]

I know that this seems ridiculous, but do you have the correct spark plugs in it? A too cold range of plugs could cause this problem.

Richard

 

[BrianQ]

ECU? How does it play into the fouling? Running hot or overheating has never been a problem; not sure about underheating. The temp gauge barely moves up when run for 5 minutes.

 

[BrianQ]

The Deere mechanics are the ones that replaced the original plugs and then moved to hotter plugs when the ones that were called for in the specs continued to foul.

 

[KYErik]

The ECU (electronic control unit) is the "brain" that receives info from all the engine sensors, determines how much fuel should be injected and then sends a signal to the injector.

The temp needle should be moving at least 25% up the gauge after driving around for 10 minutes. If it doesn't, I would replace the thermostat.

 

[Richard001]

The ECU (electronic control unit) is the "brain" that receives info from all the engine sensors, determines how much fuel should be injected and then sends a signal to the injector.

The temp needle should be moving at least 25% up the gauge after driving around for 10 minutes. If it doesn't, I would replace the thermostat.

Good idea Erik.

Brian - You can purchase infrared thermometer guns rather inexpensively now days. So to make sure what temp your coolant is at, it could be a big help. Unfortunately, the less expensive ones don't have adjustable emissivity for increased accuracy.

Here is one from Amazon: Amazon.com: Digital Infrared Thermometer Kingtop Non-contact Laser IR Temperature Gun,-58degF to 122degF: Kitchen & Dining

Richard

 

[BrianQ]

Here is the deal on the ECU. The Deere mechanics just called it the main module. They considered that right off the bat, after replacing the injector. They brought one in and replaced it, but it had no effect. Since it was close to $800 or more, when it did not do the trick, they swapped my original back in to keep costs down. They kept the new one in all the while they where running the 30 plus tests. You are thinking that the thermostat is not operating and is stuck in an open position so that it doesn't warm up quickly and runs cold (with a rich fuel mix or too much gas) as the sensors are always sensing a cold temp?

 

[BrianQ]

I'll actually give it a run of 10 minutes (once the rains stop) and replace the thermostat if she doesn't move up to 25%. That would be wonderful if it could be such a simple fix.

 

[KYErik]

Yes- if the thermostat was stuck open, the engine would never get warm and the control unit would inject more fuel (sort of like running an old engine with the choke lever pulled out).

It was good that the dealer swapped in a good control unit- but you did say that it ran good at the dealer when you left and then it ran poorly when you got back home. That makes me wonder if yours might have a problem- but I'd investigate the coolant temp/thermostat issue first.

Before you ever took it to the dealer, did it start running rough and fouling the left plug all of a sudden or has it been a gradual process?

 

[heyinway]

I have replaced the coils, the injectors, switched to a hotter plug, checked the computer module, replaced the temp sensor. Still can't get the left side to run without fouling which causes missing and loss of power. Does anyone have additional suggestions as my JD mechanics has given up on this older rig. I love the machine and wish to keep it going. The service techs contacted the main corporate service center and they said that it was too old for them to put energy into helping them solve my problem. They actually refrained from charging me for the true total of hours that they put into trying to fix it for me. They did get it running better by discovering a problem with a secondary wiring harness that attached to the temperature sensor. It ran reasonably well for the Summer, but in the cool temp it is back to erratic running. What now?

 

[heyinway]

I have replaced the coils, the injectors, switched to a hotter plug, checked the computer module, replaced the temp sensor. Still can't get the left side to run without fouling which causes missing and loss of power. Does anyone have additional suggestions as my JD mechanics has given up on this older rig. I love the machine and wish to keep it going. The service techs contacted the main corporate service center and they said that it was too old for them to put energy into helping them solve my problem. They actually refrained from charging me for the true total of hours that they put into trying to fix it for me. They did get it running better by discovering a problem with a secondary wiring harness that attached to the temperature sensor. It ran reasonably well for the Summer, but in the cool temp it is back to erratic running. What now?

Replying to an old subject....Unfortunately the fouling problem is an engineering issue. There is no cure for it.
In a nutshell...it is a 2 cylinder engine with fuel injection...one injector. The engine is obsolete...so Kawasaki isn't going to do any "fixes" for it. Some folks use a hotter spark plug on the fouling side.
If Kawasaki had engineered it with 2 injectors...lifetime engine...they didn't. It is a way over engineered engine in a beast of a tractor...John Deere does that to keep the dealer shop busy.
July, 2020...the injector (rarely fails) is over $300 (if you can find one) and the computer (rarely fails) that reads all the sensors and adjusts everything is over $1200 (if you can find one), ignition switch/control module combination (rust kills it...aftermarket from China) is $150. Anyone would be money ahead to scrap the Kawasaki and all the electronics and install a modern day engine...about $2000 new...then you would have a reliable beast.
I'm currently working on 1996 that has only had the plastic timing gear changed years ago. It has 2300 hours on it. Original injector and computer. Installed new coils and a rust damaged ignition switch/control module. It needs a new seat and $350 power steering cylinder.
Factory 800 page John Deere service manual is available as a free download online. As is a Kawasaki factory service manual.

 

[Duz1more]

The ECU (electronic control unit) is the "brain" that receives info from all the engine sensors, determines how much fuel should be injected and then sends a signal to the injector.

The temp needle should be moving at least 25% up the gauge after driving around for 10 minutes. If it doesn't, I would replace the thermostat.

I replaced the thermostat and to no avail I still have fouling of the left plug. Idles ok,.no power under a load

 

[Duz1more]

Replying to an old subject....Unfortunately the fouling problem is an engineering issue. There is no cure for it.
In a nutshell...it is a 2 cylinder engine with fuel injection...one injector. The engine is obsolete...so Kawasaki isn't going to do any "fixes" for it. Some folks use a hotter spark plug on the fouling side.
If Kawasaki had engineered it with 2 injectors...lifetime engine...they didn't. It is a way over engineered engine in a beast of a tractor...John Deere does that to keep the dealer shop busy.
July, 2020...the injector (rarely fails) is over $300 (if you can find one) and the computer (rarely fails) that reads all the sensors and adjusts everything is over $1200 (if you can find one), ignition switch/control module combination (rust kills it...aftermarket from China) is $150. Anyone would be money ahead to scrap the Kawasaki and all the electronics and install a modern day engine...about $2000 new...then you would have a reliable beast.
I'm currently working on 1996 that has only had the plastic timing gear changed years ago. It has 2300 hours on it. Original injector and computer. Installed new coils and a rust damaged ignition switch/control module. It needs a new seat and $350 power steering cylinder.
Factory 800 page John Deere service manual is available as a free download online. As is a Kawasaki factory service manual.

Has anyone bought a FD 791d replacement engine

 

[beenthere]

Duz1more
May not be firing on that left cylinder.
Next time, get it idling and pull the spark plug wire off the right side cylinder. If the engine dies, you found the problem.

 

[Duz1more]

Duz1more
May not be firing on that left cylinder.
Next time, get it idling and pull the spark plug wire off the right side cylinder. If the engine dies, you found the problem.

The engine still runs, puzzling. It went from running good to back firing in no time flat. Haven't had any problems until now. Back firing gets worse as engine warms up.

 

[beenthere]

So what happened when you had it running and pulled the spark plug wire off the right side?

 

[Duz1more]

So what happened when you had it running and pulled the spark plug wire off the right side?

Still ran , rough

 

[Duz1more]

Still ran , rough

Worse as the engine got warmer

 

[beenthere]

Same result if you pulled the left side spark plug wire off while running?

We're (or I am) missing something here.