JD 2020 Power Loss

[SDavisH]

I was mowing with my 2020 yesterday and after about 30-40 minutes it suddenly lost power. RPMs dropped and a puff of black smoke came out of the exhaust. It didn't stall and if I sat at idle for a minute I could continue mowing. Then it would occur again after only a few minutes of mowing. The tractor seems to run fine at idle. Any ideas on what could be causing this? I checked the sediment bowls on the fuel filter and didn't see any water. The front of my tractor is actually a 2120 and has a CAV Roto-Diesel injection pump. Are there any known issues with those pumps?

 

[thepumpguysc]

It sounds as if u didn't change the filter.?? CHANGE IT & report back..
Those inj. pumps will run, + or - a bucket of dirt in the fuel system.. but they gotta HAVE THE FUEL to run..
IF it has a lift/supply pump on it that feeds the inj. pump.. check it too..
IF it has a removable top on it, small screw in the center, check that too.. theres a screen in it..
Good luck & let us know..

 

[SDavisH]

Thanks, pumpguy. I did not change the fuel filters, so I will go ahead and do that. There is a fuel pump that supplies the fuel filter, but I don't believe it is the type with the removable top that has the screen you can clean out. I will report back once I've replaced the filters.

 

[Tx Jim]

I agree with thepumpguy that you should change fuel filter & also check for good fuel flow from tank to inj pump.

 

[SDavisH]

Tx Jim. What's the best way to check the flow from the tank to the pump? Disconnect the inlet line?

 

[Tx Jim]

Yes that's correct. Another thought is fuel tank isn't venting creating a vacuum. Try operating engine with a shop towel covering fuel tank filler neck.

 

[SDavisH]

Will do. Thanks, Tx Jim.

 

[SDavisH]

Okay, Fellas.

I have done the following:

- Changed the fuel filters and bled them

- Tested the fuel transfer pump. Disconnected it from the fuel filter and cranked the motor. Fuel squirted from the line.

- Checked the fuel inlet line into the injection pump. Disconnected it and fuel poured out.

- Replaced the gas cap.

I was again able to mow for about 30 minutes and then lost power (white smoke out of the exhaust and rpms dropped). The tractor seems to run fine at idle and will operate/drive at 1500 rpms. Loss of power occurs at higher rpms (ex. 2100) whether under load or not.

Any other suggestions for diagnosing this issue?

 

[Tx Jim]

Sounds typical for deteriorating inj pump drive coupler. Loosen both screws on IP timing window,be sure gasket is pried loose from IP housing. Start engine & if it operates correctly then remove check valve on IP that fuel return line attaches to. More than likely cheek valve is clogged with debris from drive coupler causing pressure inside pump to rise too high therefore pumping ceases. IP will need a new drive coupler installed which requires IP disassembly.

 

[SDavisH]

Sounds typical for deteriorating inj pump drive coupler. Loosen both screws on IP timing window,be sure gasket is pried loose from IP housing. Start engine & if it operates correctly then remove check valve on IP that fuel return line attaches to. More than likely cheek valve is clogged with debris from drive coupler causing pressure inside pump to rise too high therefore pumping ceases. IP will need a new drive coupler installed which requires IP disassembly.

Thanks, Jim

That’s a bummer. Is that an expensive repair? Do you need to worry about the engine timing before you remove a CAV IP (i.e. does the no. 1 cylinder need to be at TDC before removal)?

 

[thepumpguysc]

A- its not called a "drive coupler".. its a Flex Ring'
B- CAV pumps don't have them..
I think 2020 has keyed pump driveshaft.. either way u have to go thru the front..
Remove the 3 bolts holding the drive to the gear or the nut from the gear.. if its a nut, you'll need a puller to pop the gear off the pump shaft.
Some pump #'s will get u more information.

 

[SDavisH]

A- its not called a "drive coupler".. its a Flex Ring'
B- CAV pumps don't have them..
I think 2020 has keyed pump driveshaft.. either way u have to go thru the front..
Remove the 3 bolts holding the drive to the gear or the nut from the gear.. if its a nut, you'll need a puller to pop the gear off the pump shaft.
Some pump #'s will get u more information.

Pumpguy, are you saying I need to replace the flex ring on the pump drive shaft? Also, do I need to do anything with the timing before I remove the pump?

Below is a pic of the pump numbers

 

[Tx Jim]

Yes IIRC engine needs to be on #1 TDC before removing pump. I've read where IP needs to be disassembled in a dust free room & also where tech's have repaired them in a dusty field while using a pickup tailgate for a work bench. I've never been brave enough to disassemble an IP.

 

[SDavisH]

How do I find TDC on #1 on the compression stroke? The service manual says to manually turn the crankshaft clockwise. How do you do that?

 

[Tx Jim]

Remove bolt with pin(key 4) & cover from flywheel housing then reverse pin & insert in threaded hole. With timing widow on IP removed utilize a flywheel turning tool(special tool) or screwdriver inserted in ring gear teeth to turn engine over until lines inside IP align then pin should fit in depression in flywheel. ""Don't forget to remove pin from depression in FW after IP is installed!!""

 

[thepumpguysc]

The drive on that pump has a MASTER SPLINE it will only go on 1 way.. its almost foolproof.
U HAVE TO remove the cover infront of the pump to gain access to the 3-1/2" bolts holding the pump drive to the engine drive gear..
U don't have to worry about #1 cyl being on compression stroke..
"U CAN" remove the side cover on the pump, AFTER u shut off the fuel at the tank or pinch a rubber line..
& line up ANY of the letters in there w/ the flat on the timing clip..
It sounds like u don't have the special engine rotating tool, so you'll have to use a screwdriver on the flywheel or a 15/16{?} socket on the alternator..
I've never timed one before removing the pump.. they're fool proof.. only go on 1 way.. UNLESS u move the gear after the pump is off..
THERE IS a timing line on the OUTSIDE of the pump.. on the mounting "ear".. that lines up w/ some degree marks stamped into the engine block..
WRITE DOWN what # the timing line lines up with..

 

[Tx Jim]

thepumpguysc
Thanks for correcting my mistake. I left JD dealership back in '87 & I sure thought I was taught to put engine on #1 TDC before removing IP BUT A LOT OF WATER has run under the bridge & down the creek since '87.
thanks again,Jim

 

[SDavisH]

Thank you, Jim

 

[SDavisH]

Pumpguy, I see the timing line on the mounting flange of the IP and one on the timing gear cover, but they are not lined up. Do I just need to remember their orientation to one another or do I need to make a new mark on the timing gear cover? How do I figure out what part(s) to order for my pump and where can I order them from? Appreciate the help.

 

[thepumpguysc]

There should be a SET of marks.. degree marks.. or make your own..
"U" don't repair the pump..
You can click on my screen name on the left of the page for contact info..