Hello all, brand new poster here. We are having issues with our dozer and are looking for some advice. Codes we are seeing are F434, F431 and F437. The biggest issue is this problem is very intermittent. When it runs fine it runs awesome but will suddenly begin missing and fluctuating rpms and sometimes die. I'm afraid we inherited someone else's problem because it has a fairly new injection pump on it. Wondering if they were trying to fix what we are dealing with. We would like to be able to check if the ECU is good. Hate to spend the money on one if it's just a guess. Thanks for any help! Engine serial RG6081A128978
Welcome to HEF Farmerditcher ! Need the machine serial number please. Your symptoms sound like your engine is starving for fuel. First thing I would do is check fuel pressure if you have that capability. Spec on that machine should be 29-30 psi at low idle measured at the fuel filter. You will want to check the pressure when the issue is happening however. F437 is for the fuel temp sensor and F434 and 431 are for the rack actuator in the injection pump. Do these codes "pop" up when the issue happens or are they just in the stored code list? Rack codes can sometimes pop up intermittently without actually having an issue on those machines. If these codes pop up during the issue and your fuel pressure is good then your left with a wiring/connection issue (especially check the E24 white wire from ECU to the Rack actuator) or an ECU issue if the injection pump has been replaced.
I'm betting on floaters in the fuel TANK..
When the issue begins is when the 431/434 codes pop up. I plan to try and lay my hands on every inch of the harness between the injection pump and the ECU and wiggle it around while running.
Could it be algae in the fuel?
I suppose anything is possible, thank you. When I changed filters a couple days ago the fuel I dumped out of them looked great.
I help a buddy put a clutch in a tractor and he was having issues too. The only thing that I could tell was on the screen on the sediment bowl had slime on it. If it seems to run good after a filter change then it could be that. I know he bought some algae treatment from Jeff (amazon) that wasnt terribly expensive. Hope you get it figured out.
Well here is an update where we are so far. We have replaced both fuel filters, and verified we have good fuel flow to the lift pump. Teed in a pressure gauge between lift pump and injection pump and get just under 20 psi when idling. When the miss starts occurring fuel pressure is about 18 psi and will fluctuate some while running erratically until it dies. With key on so fuel shutoff solenoid Is open, we can only attain 18-20 psi on guage with hand pump on lift pump. We are going to replace the overflow valve with one from another engine and see if we can build more pressure. Another thing is this issue only arises after machine has been working for a couple hrs. Will watch fuel pressure in the morning again when it's cold. Any advice from here is greatly appreciated, thanks!
I agree.. overflow valve
Do you know of a source for these overflow valves? Not available through John Deere and Bosch dealer is amazingly high! Nearly $300....
Do u have the p#..??
JD# for pump RE67448 Overflow valve Bosch# 2417413077 I can get the Bosch# off the inj pump tomorrow
You mean one of these. Deere has plenty in stock.
Yes, that is what I'm after. Thank you! Guess I didn't look hard enough online yesterday. I was talking to a parts guy and he couldn't find it either.
Dam your fuel injection guy must hate u..??!!!! THATS LIST PRICE.. then they’re gonna hit u w freight charges & tax.. Lemme know wHat Deere sells for & I’ll see if I can beat it..
The price is right there Pumpguy, $273.xx. As far as I know, the prices are correct and standard across any JD dealer.
I can beat. Send me an email.. screen name @ aol. com
I have a new 1.. & I’m having a 1/2 price sale today..
So, after a good bit more diagnosing of the fuel supply and flow to the injection pump, we are now thinking this is an electrical issue. We have checked over the wiring harness very thoroughly with cab up and see no visible issue with it. We got ohm values from a pump shop for the rack actuator and sensors and they all checked out good right after the machine was acting up. We plan to put a used ECU on the machine tomorrow and see what happens. This ECU will come off a dozer just like ours. Do we assume it will be programmed to run our machine or not?
So long as the donor machine has the same engine and injection pump it should work.
Well we are still not going with this dozer. Put a different ECU on it today and it did not change a thing. We are confident that fuel flow and pressure to the inj pump are not a problem. Like I said earlier, it VERY consistently starts and runs fine for 2-3 hours every morning before it gets in a mood. First thing it will do is begin missing for 30 seconds or less before it begins wildly accelerating and deaccelerating until it dies, missing all the while. During this time the ECU takes control of the throttle and we can't control it. Also still seeing the F434 and F431 codes that pop up as the issue arises. Once it throws a fit after a couple hours of warming up it will remain in it's mood for several hrs. The first thing that occurs is always the miss, followed by the wild throttle. It will restart normally and run for a minute or less all day long after the mood begins. I am curious why we are getting a miss as this is a typical Bosch inline pump with mechanical injectors. If the miss is being caused by a pump or injector problem, would that trigger the ECU to start acting wild with the throttle? And WHY would it take 2-3 hours of working to show up? Sorry for all the questions as we are getting a little worn down here. We are very thankful for any and all advice we can get at this point! Thank you.
I would rig up clear lines in the supply and return lines to see if you are getting air (or pulling a vacuum) when the issue acts up, possibly from something floating around in the tank. If the engine starts to starve fuel fuel it will act just like that (miss, wandering rpm). The rack position codes might be a reaction to what the controller thinks it should be seeing (rack position vs engine rpm).
mg is correct.. the ONLY WAY to rule it out is to put clear lines on the inlet.. Its not uncommon for the rack actuator in the inj. pump to be worn & act up when it gets warm.. actually its VERY common.. I couldnt count how many I've replaced.. literally in the thousands..
Check the fuel cap/tank vent isnt plugged and drawing a vacuum in tank over time. Clear lines may not show anything if its not moving any fuel but a supply pressure test will.
@Farmerditcher were you able to figure out your problem. Our 850c is doing the exact same thing. Same codes and same symptoms. It's like you've got our machine. We had the pump done just under a year ago
So after rigging up a section of clear line in front of the lift pump we began to notice small bubbles going in when the machine would begin acting up. Bypassed the fuel filter/water separator and still were getting bubbles. Decided to check if we had a screen in the outlet of the fuel tank. Sure enough found one and it had a bunch of crap around it. Took it out and are running an inline screen up near the engine where we can change easily. I feel now that our problem all along was definitely rusty crap in the fuel tank that was building up on the screen after a couple hours of running. Then it would start getting air somewhere as it was under a vacuum. Seems amazingly simple now! Our next step should be to take the tank off and cut it open and clean it but thats too big an undertaking at the moment. Looking down the fill hole you cannot even see much of the bottom of the tank as there is a baffle that runs down near the hole. Do any of you have experience or an idea for cleaning a tank like this? Thank you all for your help along the way with this dozer!
Maybe rig a a circulation pump tied to suction line and return with filters. I would make sure your pump will at least move as much fph let it run over nights. Just my fat guy idea. Jason