Dad just bought a John Deere 4020 diesel for a good price. its fairly rough, and needs some work, but we are gonna at least try and get it in good mechanical shape. My question is that it is white smoking quite a bit, and missing a little. Also, if you rev it up much and hold it at a steady RPM anything over half throttle, it runs ok for a second then, its like it dumps a bunch of fuel into it, and kills it out. It start blowing white and gray smoke, and if you let off of it, it will eventually settle itself out, and go back to idling. Also, it seems to be blowing oil out of the exhaust? It could be fuel, but dad smelled of it and seemed to think it was oil. It definately has something wrong we just arent sure what. I am thinking it may be a couple injectors sticking open and popping off to early causing them to dump fuel. The motor sounds good as far as no knocks or anything, and it fires up as soon as you start cranking. Hold steady 35psi of oil pressure. Anyways. Anyone have an ideas? Thanks

Eric

 

Sounds to me a lot like some stuck injectors... If you need new injectors I can set you up with some different sticks from a different app and some sealing washers that are thinner to get the injector down into the bowl a little more. All that combined with a small timing bump (about 3* past stock) will make it way more responsive and start a lot easier. Also, pull the valve cover and run it once to watch the valve train may have a problem there with a cracked rocker or the like. I'll see what the Doctor thinks tomorrow when I go to the shop and get back to you (my father and I own a business called Tractor Doctor :P )<- we work mainly on Deeres

 

It is common for John Deere's (20,30,40,50,55 series especially) to smoke alot when first started in the morning (cold outside or not), or whenever. But usually they clear up in about 30 seconds to a couple minutes. I will try to do some research about 20 series and hopefully will be able to help. I have one 4020, the rest are 40, 50, 55 series. It may take me a couple days, but I will get back to you as soon as possible. I am guessing you have a faulty injector though.

Ed

 

Thanks guys. We are figuring it is an injector problem, but arent sure yet. The weird thing is when you are going uphill it starts smoking worse. Its a dark grey smoke. It doesent blue smoke at all which is why I dont think it is burning oil. It also has no fuel in the oil. We thought at first maybe some broken rings, but im leaning more towards an injector problem now. Its just confusing as to why it does it at higher RPM's, and going uphill more than anything. At idle it will clear up most of the white smoke, but rev it up and hold it there for a second and it starts pouring the white/gray smoke, and kinda killing out. Dad said he thought he could get injectors for about $50 a pop. Thanks for any help though guys! I think im really gonna like this tractor when we get it figured out

Eric

 

Just uploaded some pic's guys. She's pretty rough but we got it for cheap ill post em up when they get approved


Eric

 

It sounds like you have some bad injectors and possibly a bad injection pump as well. The advance in the pump isn't working properly. That is why it acts up over half throttle. The advance pistons could be sticky, or the elastomer ring on the govenor weight retainer has disintegrated plugging up the return fitting. This causes the housing pressure to increase and therefore the advance cannot operate correctly. Either problem requires a rebuilt injection pump. The "oil out the exhaust" is unburnt fuel mixing with carbon in the exhaust. It does look and smell like oil, but it isn't. If it is an early 4020, it might have bosch or Bendix poppet injectors. They have a nozzle and a valve rather than a one piece nozzle. They are difficult to find parts for. Also, they have alignment marks that have to be lined up if the injectors are taken apart. The later 4020 used Roosa Master pencil injectors which are readily available at your local friendly John Deere dealer.

 

Good info! It would be great if all it turned out to be were the injectors, or the pump. thats a simple fix. I also thought it must be fuel coming out the pipe mixing with the soot and making it black, but it didnt smell like it so it was a little confusing. Thanks for the help. Not sure how fast we will move with getting it fixed, but i will keep your guys posted

Eric

 

I agree with ckt, I work for an equipment dealer and we see stuff come in like this all the time...99% of the time its a bad injector or two and yes its commen on these tractors. Do that and bump the timing a smidge and you'll be golden, she'll run like new.

 

How many hours are on the tractor? The 404 is a tough motor. With an overhaul, new injectors and some pump work, it'll be better than new.

 

I’m going to agree with Mt Ram, and CKT…

I think it is your injector pump not advancing right. But try getting a set of injectors first. I could just repeat what everyone else has said, but get the injectors and you’ll be able to rule that out hopefully.

Ed

 

Pics..







Eric

 

Hey it may look a little weathered but it's a good runner - it's really trying to run even if it's not feeling so hot....

Wow, this discussion takes me back to how diesels are supposed to be and run...I think our country may look back on all these diesel reg's they are imposing now and really regret it sometime.

Looks like a neat project - good luck...

 

Wow looking at those pictures just takes me straight home. I dont know how many hours ive sat on a 4020. We use one just like it except with a loader to swath 400acres with twice a year.
Cant say much on the machanical end atleast nothin new. Good luck.