Combines N7 bogging down

[OKFarmer]

Sounds like fuel restriction. Do you have uninterrupted flow to the input on the injector pumpIJ On later model gleaners there is an in-line fuel screen up on the engine sled just before the filter. Could it be cloggedIJ I assume you have changed filters. One time someone told me to see how much fuel is returning to the tank from the injector pump. There should always be some. If there is none you may have fuel restriction problem ahead of the pump. If there is some "while" it is bogging down then you have pump trouble for sure. I never quite knew how to test this though.... OKFarmer

 

[marshall]

I can not find a restriction in the lines. I have disassembled and blown out. I did not see a screen. Appears to be getting plenty of fuel from tank. Jus installed electric pump. Very wet here but I plan to try it this afternoon. Thanks for the heads up on the screen.

 

[marshall]

How is wheat in your areaIJ I am in NETX and the wheat was hurt by late freeze. We are averaging around 30bu_ac. We normally average 60.

 

[OKFarmer]

Wheat here is freeze damaged, but not as bad as South of here. We are in Alva area. Had some hail damage here too 6-7000 acres in Woods County alone. Expecting high 30's. No one has cut much. Wheat suckered out after freeze and those heads made wheat so we are waiting on them to dry down. It will be interesting to see if your electric pump helps. Our R62 has lift pump back there. We just replaced it because it was throwing codes in the engine computer. Be GlAD your N7 doesn't have an ECM on the engine. Is your combine heating any when it does thisIJ I still think it has to be fuel restriction, but if it isn't then some valve is bypassing in the injector pump. I guess your injectors can get clogged and cause excessive line pressure on the output of the pump causing a "self-protect" valve of some sort to bypass. We always run a hefty does of transmission fluid in at least one tank of fuel per year to clean injectors. You could try that. Won't hurt anything. OKFarmer

 

[Pengs5]

Check that filler cap is breathing on tank it has been known if blocked to hinder at peak loads. New inner safety airfilter and outer for that matter .Have you cleaned out the little cyclones in air filter intake. little bit longer exhaust stack with bend away from air intake as we reckon slight winds tend to push exhaust back in (yuk sorry Al Gore )if std pipe with rain cap flapper. Check aspirator venturi in exhaust pipe some wear_crack fall down and impede exhaust flow let alone fire hazard if heats_sparks through to air filter a often overlooked area. After all the obvious check out injectors and inj pump. One of the nicest diesel engines ever built in my opinion. Great starter,smooth,torquey,power,cracking sound,reliable even though machine could do with another 100Hp. Pengs5

 

[tbran]

soft red winter wheat in the mid south is poor to worse. Extreame low test wt. yields 13-50 bu max so far. Too much water and cool temp at pollentation - white scab. Can't seem to get a break. After the two worst droughts on record, now the wettest spring on record. Corn replanted 2-3 times, almost no soybeans planted. It just has to be Al Gores fault - he is FROM Tn. ya know.

 

[marshall]

Thanks for the suggestions. I have check most of those areas. I have not changed the inter air filter since this started. I will remove tomorrow and check. It has been wet here so we have not been harvesting. I will keep everyone posted.

 

[marshall]

looks like I will end up with around 30bu average. Hogs have taken about 20%. They only get the best wheat. Hopefully my beans and milo will make up the difference. I would say all the wheat in NE Texas will be low yielding. Row crops have struggled with to much moisture.

 

[NDDan]

Does it seem to take any more RPM than normal to get fuel restriction light offIJ I'd be checking a couple things. First there are a couple light spring check valves in hand pump on main pump. One should be right under hand pump and the other under a plug. Junk holding one or the other off its seat or broken spring will reduce charge pressure. Next I would check out the fuel charge pressure relief valve that return line is hooked to on back side of pump. Spring or seat could be all banged out with may have dropped your charge pressure to low. Good luck

 

[marshall]

ok - will check. the hand pump does leak when you use it. I also never pumps up tight.