Jinma 254 starting problem

[Raw Bone]

Hello Everybody,

I'm new this website and I am having a problem starting my Jinma 254 after it has been sitting for about 4 months. It has been stored inside and when I went to start it, it started after just a couples of revulsions. However it starting gaining rpm's without giving it any throttle and I pulled the kill button/plunger to stop the fuel feed and it died. When I attempted to start it again it will crank just fine but won't fire. Normally when I crank it to start I'll get a small cloud of black smoke prior to it starting, but after the runaway start I just get a very little light gray smoke that dissipates as soon as I stop cranking it. It seems as if I'm not getting any fuel. The tank is full and the glass sediment bowl just below the tank is full and clean. If I have lost the prime, how do I get this problem cured? Any suggestions would be greatly appreciated.

Thank You,

Raw Bone

 

[RonMar]

You might get more answers with this in the chinese section, but don't repost it there(multiple posts are very annoying). Send a message to admin and ask them to move this one there. Down in the lower left below where your name and avitar go is a little red triangle to report the post to admin. Click on that and there wll be an area to write them a note to tell them where you want it moved.

To help try and solve your problem, when you pulled the kill knob, it works a lever on the injector pump. When you release the kill knob and it goes all the way back into it's run position, does the lever on the injector pump also go all the way back into the run position? IF the lever didn't go all the way back, this could explain why it won't start now. How much throttle are you giving it for startup? I usually give it about 1/3, or about the position that gives me about 1200RPM when running. and as soon as it fires, I pull the throttle back to the idle position and let it warm up at it's 900RPM idle. How is your cranking RPM. A little slower RPm can make a big difference in how well it will start.

If you had lost pump prime, the engine probably wouldn't have started in the first place. How warm or cold is the engine. Did you try glowplugs during that first start? Could anything possibly have nested in the air intake pipe during the past 4 months?

Just a couple of things to look at...

 

[psj12]

From the initial runaway situation it may be possible that the rack is binding or stuck. The govenor flyweight/spring pressure couldn't move the rack to a reduced fuel position but you did manually. Now the govenor cannot overcome the no fuel position on the rack. When did you last change or add lube oil to the pump sump? Sometimes the rack can be freed by lubing it and manually moving it back and forth.

 

[Diamondpilot]

I think its a stuck rack or something else in the pump. Have you checked the injector pump oil for clues? Is it possible all the pump oil ran out during storage?

Chris

 

[greg_g]

Yup, Chris has likely identified your problem. I too am betting one or more piston (inside the injection pump) stuck during those four months sitting idle. When a piston sticks, the governor is fooled into thinking it has to cope with a full throttle situation. Usual reason is that new owners don't realize that the pump assembly has it's own oil sump that must be checked regularly. Less common -but still possible - is an actual pump casualty.

It's possible to partially disassemble the pump and free a stuck piston. If no associated damage has occurred, a little local lube followed by draining/refilling the pump sump (with engine oil) should free it up. After that, check periodically to see if any diesel fuel has seeped through into the sump. I try to drain/refill mine on a semi-annual schedule (spring/fall).

//greg//

 

[Raw Bone]

Hello Again,

Do you have anymore info about how to free these stuck injector pump pistons that you're refering too? If you have any photos of this fix could you post me a reply with them? I'm going to remove my injector pump to gain access to the governor located at the back of the pump. I noticed that ears for the mounting bolts are slotted and I'm pretty sure that this is for adjustment / timing of some sort, for the pump. I'm going to match-mark it's present location before removal so I can reinstall it in the same position. I would like to know what the adjustment is for exactly. Any information in regard to this will be appreciated.

Thank You
Raw Bone

 

[greg_g]

Well, I've never had the problem with any of my pumps. But I'm almost certain (most of) those who've described "unsticking" pistons did so without removing the pump from the tractor. I can't recall where I saw the photos now, but the pump was partially disassembled - but still on the engine. Not all pumps are the same of course. But for mine, I'd just start by removing the hard lines -and see where that takes me.

//greg//

 

[Rich Waugh]

Those slots are, I believe, how you adjust the injector timing, which is similar in function to th espark timing on a gas engine. I would definitely look to do whatever I could to free up the pistons without removing the pump if at all possible. Drain both the pump and the governor ( you should get about 20 oz. of oil, I believe) and then refill with white kerosene and run it through a few minutes and drain out. If the engine won't start at all, just pull the compression release and crank the engine for a minute or so, in bursts of ten seconds or less so as not to overheat the starter. After draining the flush out, refill with the proper lube, giving it time to run from one side to the other to be sure both sides are properly filled. After that, you can try using the hand pump to re-prime it if you think it is out of fuel.

I trust you have actually pulled the fuel line where it enters the pump to make sure fluel is actually flowing. There are hidden filters/strainers in the tank that can get clogged with dirt, debris and bugs and the sediment bowl and external filter look full bu tno fuel is flowing to the pump.

Let us know how this works out and we'll see what else we can come up with if that doesn't work for you.

Rich

 

[biggerten]

Drain both the pump and the governor ( you should get about 20 oz. of oil, I believe)

Considerably less, just a few ounces.

 

[Red55]

When I change my injector pump oil I get considerably less too (about 12oz) Yes I do pull both drain plugs. Kinda leary of running with kerosene in the pump might be better with diesel either way I wouldnot let the engine run without the proper oil. Don't know if it would help but what about AT fluid? Hear stories all the time on how it will flush out a dirty engine and then blow it up when the oil pump pick-up screen gets clogged Good Luck -Ed