John Deere 6415/4045 engine running rough, need help!

[HTEoregon]

Got a call from a customer the other day and have been tinkering on this tractor since. I would appreciate any advice from anyone with experience on this engine.

Engine runs, idles fine. Idle is a bit rough. When throttling engine up slowly engine runs very rough, sounds and behaves similar to air in fuel. When snapping throttle quickly it seems to sound fine revving up.

Checked pressure and fuel flow at line to water separator from tank, my fuel gauge shows vacuum as well. Gauge read 0psi, no restriction from tank. Fuel sight glass shows no air.

Checked pressure and fuel flow at line to primary fuel filter. Primary filter is post water separator, with the electric lift pump plumbed between the two. Fuel pressure pegged my gauge at 70 psi and again no air in fuel sight glass connected to fuel gauge.

Replaced fuel filters. Removed fuel hard line from Primary filter housing to injection pump and found one of the seals in terrible shape. Replaced both fuel line seals. No change. Removed and cleaned screen on injection pump. Removed and inspected check valve on return fitting from injection pump. Clean and operational. Replaced o-rings under screw on caps on top of filter housings to eliminate them being a possibility. Replaced fuel return nozzles and seals due to some suggestions on other forums I read.

Supply pressure seems to be more than enough. Can't see air in fuel. Fresh diesel. This tractor does not sit during off season, they run it consistently. He was mowing his pasture when this started suddenly, no
warning. I noticed tonight the glow plug light is blinking, not sure if that's related to this issue or not.

I just want to make sure I dot all my i's and cross my it's before I commit to pulling and pop testing injectors and running over head on motor. When bleeding injection lines each cylinder dropped off the same as all the others. Would expect to not hear a difference in one if there was a dead hole. Does anyone here more familiar with these tractors/engines/fuel systems know if there's anything I've missed on this machine? I would like to be sure I've exhausted all options before telling the customer we gotta go deeper!

Thanks!

 

[mg2361]

Please post the engine serial number. Which injection system is on this engine? Sounds like you have an inline fuel injection pump??

 

[HTEoregon]

Please post the engine serial number. Which injection system is on this engine? Sounds like you have an inline fuel injection pump??

ESN is CD4045H867860. Looks like a stanadyne pump, jd p/n SE501234

 

[mg2361]

When you said 70 psi fuel pressure, I thought it was an inline injection pump. What you have is a DE10 Stanadyne, which should only have 3-6 psi of supply pressure. With that being said, your symptoms are similar to a fuel supply problem, or you have a defective wiring to the injection pump, defective injection pump or ECU. It is not the injectors.

If the wiring is good from the ECU to the injection pump, then you need someone with Service Advisor to look at some readings in there to try and determine if the injection pump or the ECU are defective.

 

[HTEoregon]

When you said 70 psi fuel pressure, I thought it was an inline injection pump. What you have is a DE10 Stanadyne, which should only have 3-6 psi of supply pressure. With that being said, your symptoms are similar to a fuel supply problem, or you have a defective wiring to the injection pump, defective injection pump or ECU. It is not the injectors.

If the wiring is good from the ECU to the injection pump, then you need someone with Service Advisor to look at some readings in there to try and determine if the injection pump or the ECU are defective.

That's the direction we're headed. Spoke to the owner today I guess they replaced the injection pump in the last 100 hrs. Ongoing issue that I wasn't aware of. Apparently they replaced the pump to try and fix the issue. I only mentioned injectors because of a conversation I had with the local JD tech about it. I myself do not believe injectors are this issue. The miss/runability issue is across the board and does not seem to be a single cylinder issue. Do you know where the ecu is located on this model tractor?

 

[mg2361]

Do you know where the ecu is located on this model tractor?

Unfortunately, no. I do not work on the green tractors, just the yellow. Parts page indicates it is in the cab?

 

[HTEoregon]

Unfortunately, no. I do not work on the green tractors, just the yellow. Parts page indicates it is in the cab?


View attachment 309429View attachment 309430

I apologize for the late reply, been waiting on my edl to show up before I got back out on the tractor. I worked on it last night, monitored throttle pedal and lever potentiometer and everything looked kosher on those.

One thing I did notice was that while monitoring fuel rate during potentiometer testing, the fuel rate drops to 0 in time with the miss the engine has. At idle, when the motor is not missing, you get a rate of .05-.015 liters an hour. Stabbing throttle pedal that number rises but not does drop to 0. When easing in to throttle that number increases with pedal position, but drops to 0 consistently every time the engine misses.

I attempted to monitor valve closing time on the pump per a DTAC case that was similar to what I was seeing but that test does not appear on service advisor. DTAC case says that is a level 12 ecu test, but SA says this tractor is a level 4 ECU but the ECU itself has a parts sticker on it that says L12 so i'm not sure what to think of that. Maybe somebody with more deere experience can chime in, its been awhile since I was in the AG world.

When clicking on tests tab in SA it lists controllers on the tractor, BCU and ECU. I am able to click on BCU but ECU is grayed out and has an X on it. I am unsure if this is because the BCU has active codes and the ECU does not? This led me to look at troubleshoot steps for ECU not communicating with SA and I ended up testing can hi-lo pins for resistance and found 37k ohms of resistance. I am currently going down that rabbit hole today.

Spoke with the local JD techs at the local dealer yesterday, showed them videos, and none of them have seen this issue before. Last visit I was out I ended up running a fuel line straight from my diesel jerry can, to the electric lift pump, then straight to the injection pump completely eliminating supply side being an issue. Lift pump pressure seems extremely high, but this tractor was operating normally up until it wasn't so I'm trying not to focus too much on that. I've never seen a lift pump failure cause excessive supply pressure but that doesn't mean it doesn't happen.

If you or anybody else has any ideas, I would really appreciate the assistance. I'm at a loss here, and am hesitant to condemn anything without any evidence. The fuel rate dropping to 0 is the only breadcrumb I have so far to go on. TIA!

 

[heymccall]

On all my Deeres, the separator filter has an add-on water bowl. There is an Oring that goes on top the bowl, to mate with filter. If it's missing, it'll suck air under load, but, not leak fuel when the engine is off.

 

[HTEoregon]

On all my Deeres, the separator filter has an add-on water bowl. There is an Oring that goes on top the bowl, to mate with filter. If it's missing, it'll suck air under load, but, not leak fuel when the engine is off.

This tractor does not have a bowl, just the plastic valve that can be twisted to drain. I know what you're referring to, this does not have it. I replaced the o-rings under the screw on caps on top of the filter housings to eliminate them, but I bypassed the entire low pressure side and tested pressure and for air in fuel with an acrylic sight tube and everything checked out.

 

[mg2361]

Definitely an issue if you have 37 K-Ohms on the CAN HI-LO resistance check.

Level 4 would have a Bosch injection pump with it's own controller (in conjunction with the Deere ECU) mounted on top of the pump itself.

Level 12 has the Stanadyne DE10.

Try connecting again, but use a 4045 OEM engine as your model rather than the tractor model. Will it communicate with the ECU that way?

 

[HTEoregon]

Definitely an issue if you have 37 K-Ohms on the CAN HI-LO resistance check.

Level 4 would have a Bosch injection pump with it's own controller (in conjunction with the Deere ECU) mounted on top of the pump itself.

Level 12 has the Stanadyne DE10.

Try connecting again, but use a 4045 OEM engine as your model rather than the tractor model. Will it communicate with the ECU that way?

On the phone with the local deere expert, and have the machine tore apart at the moment. I was in the process of disconnecting ECU BCU and terminators to see if my resistance changes. Found one terminator by the ecm but still trying to locate the other one.

 

[HTEoregon]

Definitely an issue if you have 37 K-Ohms on the CAN HI-LO resistance check.

Level 4 would have a Bosch injection pump with it's own controller (in conjunction with the Deere ECU) mounted on top of the pump itself.

Level 12 has the Stanadyne DE10.

Try connecting again, but use a 4045 OEM engine as your model rather than the tractor model. Will it communicate with the ECU that way?

The older deere guy i've been communicating with is a bit old school, and basically disregarded the high resistance reading and said he checks voltages. 37k ohms seems to me like it would be a substantial issue.

 

[HTEoregon]

Definitely an issue if you have 37 K-Ohms on the CAN HI-LO resistance check.

Level 4 would have a Bosch injection pump with it's own controller (in conjunction with the Deere ECU) mounted on top of the pump itself.

Level 12 has the Stanadyne DE10.

Try connecting again, but use a 4045 OEM engine as your model rather than the tractor model. Will it communicate with the ECU that way?

Got everything hooked back up and tried to connect under 4045 as you suggested, fails to connect every time. If I switch back to 6415 it will connect.

 

[HTEoregon]

I have since found a mouse nest in the RH console, cant find any wire damage. Since I have found the nest and have been rummaging around in the console where the main harness is I have been able to occasionally start it and it runs normally. When fuel rate is viewed on SA it behaves normally and does not drop to zero. This is the first time it has done this in the three separate visits I have had on this tractor. I thought that maybe there is wire damage I can't see, it's a difficult spot to access harness, so I ran jumper cables from terminals A3 and K2 on the ECU directly to the solenoid on the injection pump to no effect. I'm thinking this is still a communication issue on the canbus network but I haven't been able to find the culprit. I hooked my meter leads to can hi and lo on the diag connector and began disconnecting ecu, bcu, and terminator and none had an effect on the extremely high resistance i'm seeing. Unplugging and plugging in terminator got resistance to drop to 5k ohms which is obviously still way too high. I believe SA called for 40-70 ohms. I left my meter leads hooked up to the diag connector pins and wiggled and jiggled harness everywhere I could get my hands on it hoping to see any kind of fluctuation. Haven't seen any changes. Anybody have any input on this?