655, 1/2 tank, rpms's decrease

workinallthetime · Mar 13, 2007

ok jd guys, i have been awarded the task of bringing back to life a jd455. first i was told the thing was just parked when he was done mowing, now i am told he has had a problem with the thing running when it gets below 1/2 tank. says the rpms drop and the last time it just died. the tractor has been sitting in a yard for 1 year in the spot it died. Im thinking possibly the transfer pump but the guy installed a new one, possibly backwards i duno. anyone have a problem like this where you lose rpms related to fuel level? I know the obvious clean fuel, fuel filter, purge system, but anything else?
thanks jd boys

DieselPower · Mar 14, 2007

If it is old the pickup tube in the fuel tank could have a hole in it and when it get's to a half tank it starts to suck air instead of fuel. I have seen this happen before in over the road tractor trailers that have a two piece pick up tube that is soldered together. After years of bouncing up and down the road the joint gives out and it starts to suck air and the engine starts to stumble and eventually die around the 1/2 tank level. I would pull the pickup tube and inspect it.

workinallthetime · Mar 14, 2007

thats the same thing i found out from the jd dealer today, i didnt even think of that, like you i have seen that in isuzu box trucks.

workinallthetime · Mar 20, 2007

well got the thing to my house last night, there is fuel to and out of the injection pump, very small amount at actual lines. pulled the glow plugs and seems like there is very little compression at the bach cylinder also the thing is freight training real bad (blow by) i think its hurt, maybe real bad. duno what kind of compression a yanmar has but this thing doesnt make enough to blow my finger off the hole.

DieselPower · Mar 20, 2007

Well that sure don't sound good. If it can't even blow your finger off the glow plug hole your loosing your compression somewhere. Either a hole burned in the piston or a busted valve. Either way, that sucks.

workinallthetime · Mar 20, 2007

the guy bought it for 1000 with a 4 foot finish mower, paid me a 150.00 to pick it up and check it out. at this point im recomending him to take it to a shop. I dont want to get involved with it anymore than i am. I really wanted to make it run but doesnt look like it is going to happen in my garage. the thing looks pretty easy to work on i just dont have the time to take on another project right now. with all the blow by i bet there is a hole in the piston or some sort of cylinder damage.

ohh well case closed for me ill post on here what it fianlly takes to get it runnin if it does ever run. thanks diesel