Combines 8780xp fuel problems

kernal

Guest
Is this a mechanical in-line pump or the electronic versionIJIf prior to 2000 model=mechanical -check the waste gate actuator diaphram.Unhook hose to waste gate and plug with a 1_4 inch bolt.Take to field and see if power is back.If diaphram is leaking you will not activate aneroid on injection pump to "fuel" the engine.Have had this happen on R series Gleaners prior to the year 2000.
 

Jeff71

Guest
Thank's for the reply. It's a 2002. I have since been told by the injection pump repair place that they can't help me. It's an electronically controlled pump and would have to go back to Cummins. Funny, the Cummins mechanic didn't even offer that as a solution. Perhaps the pump would have to go to some Case IH authorized repair place now. It hasn't been much fun. Every thing I tried came to no good. The mechanic is supposed to be showing up with a pump today. Time will tell.
 

dav11

Guest
I have an 8780xp, 2000 model, had to put new fuel pump on last fall, it more than likely is a electronic system like mine, it actually is not a injection pump it is more of a pressure pump-- it supplies fuel to the injectors at 6000psi and electronics tell injectors when to fire-- it costed me almost 5000 grand-- return on my core was 1200, but had to pay mechanic for 3 trips out to figure out what was wrong, I was then and still am not very happy with Cummins, now they have many updates for that system so beware, one is a wire hookup to the fuel sensor switch,very few diesel repair shops will do anything with them, you basically have to go to Cummins, and mine still does not run the way it should , the motor gains and looses rpms and I have come to end of filed and unloaded grain tank and slowed the engine down to idle and it sometimes will die,I have had the Cummins man out and paid him 1800 to find problem and it is still there, I would never buy this machine again, I wish you good luck.
 

dav11

Guest
i forgot to add, you may want to check the accumulator, inside there are 2 porcelian pins and it is very common for them to break, that what happened to mine, if that happened there will be tiny white pieces everywhere so be sure to blow out all fuel lines so they are clean, and on the fuel sensor switch, there is an update, if the wiring hookup is a rectangular shape, you will need a adapter to make a new pump work and Cummins does not have enough brains to put it with the new pump so you need to order it from them and wait another 4 days or do what I did cut off the stupid end and use butt connectors and hook them up but be sure to mark each one before cutting because one end has numbers and other has letters, good luck.
 

hv_user

Guest
I have a 2002 8780xp and have not had the fuel problem and hope I don't.Are you happy with the rest of the machineIJI think part of the problem is cummins is not happey with Agco when they parted ways but that does not give them the right to give poor service.The sisu is alot better engine and that was a good move. good luck
 

Jeff71

Guest
Where and what is the accumulatorIJ Cummins referred me to CaseIH for parts. My mechanic was from a local truck service place. He has worked on quite a few of these and remarked the setup in my combine is similar to what the Dodge pickup with the Cummins engines has. Fuel pressure is very important with this system. Any drop in fuel pressure starves the injection pump and scores it. Then you are done and the only option is to replace the injection pump. He replaces the supply pump whenever he replaces an injection pump. The mechanic suggested replacing the electric pump every so often to save that expensive injection pump. He said there was a fuel pressure warning light available from Cummins. I will check into that. Also I have vowed to change fuel filters more often and check that filter for water periodically no matter what a pain it is to get to. I have put better filters on my supply tanks and will check them for water more often as well. It certainly runs with much more power but I notice the digital tach bounces about 30 rpm. Hope that's not a bad thing. Does anyone know when they started with this electronically controlled injection pumpIJ
 

dav11

Guest
I would have to say that I am satisfied with the machine itself but the engine has been an ongoing problem, the engine seems to run fine until it gets warmed up to normal running temperature and then odd things start happening, I change fule filters every couple days and I have cleaned that in line filter nothing seems to help, when the mechanic from Cummins was out we ran it in the field for about close to 45 minutes and it run perfect- went cutting soybeans and worked most of the day and started its usually cycle-- when engine rpms go down far enough that orange check engine light comes on and it stays on until engine rpms come back where they should-- usually from maybe a second to as much as 10 seconds, when you slow engine down to idlethen you can usually really tell it, and it has actually died while idling but always starts again and he said if anything fails iti supposed to shut down engine and you will not be able to start it again,when I first bought machine it had that "rice beater" in the front, and that thing in corn was a disaster, it chopped the ears up so bad tiny bits of cobs would plug the sieves and then corn would come out the back over the sieves so had to put in that helical one and that really helped but if corn has a lot of moisture like it does this year around here i still get some of those bits of cob because the more moisture corn has the softer the cob is and you have to close concave more to shell it so cobs break up easier,I wish the sieves would be made with a little heavier material, the finns are so thin the tend to bend up way on the back, I just hope the engine makes it with any more expense as I have about 320 acres of corn left, and its been going slow, and right now it is raining here, I quess I need some good luck!
 

Jeff71

Guest
Do you have three lights in a row, top one red that says stop engine, middle, yellow says check engine, bottom yellow, says wait to startIJ In my machine next to those three lights is a big silver button I think it is labeled engine diagnostics. After an incident where the check engine light comes on you can shut the machine and engine off, turn the key to start position and push that silver button down and hold it there. As I recall the red light comes on then the yellow light starts to flash. count how many times it flashes. there will be a pause then the light will flash again, count this number, another pause and count the final number of flashes. I have learned that code 4-5-6 is the fuel pressure sensor code. Code 2-7-5 is the front selonoid. There isn't a thing about this in the book and my MF dealer couldn't help either. There was one cummins guy at a truck repair place that walked me through this on the phone. The code that came up was 2-7-5. this guy couldn't come out for a week or so. It was another truck mechanic that came out and hooked up a laptop to get the same code but the software ran him through some troubleshooting and of course I ended up replacing the charge pump and the injection pump. I was down for week waiting for my parts and ran about three days at half power before that. I have yet to get into the corn and have 500 acres ahead of me. Good luck!
 
 
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