Oil & Fuel Jinma 404 fuel problem.

[Realhyper]

Hi, I have taken delivery of a new Jinma 404 tractor this week and having problems already. The tractor idles good but falls on it's face under acceleration. If we pump the fuel transfer pump to provide more pressure it runs good at wide open throttle, but soon stumbles back to running poorly. I ran this across jinmaparts.com and they feel it is the fuel transfer pump that is leaking and needs replaced. I pulled the fuel transfer pump off and disassembled it and found no problems. Anyone have an ideas? The importer I bought it from is not mechanically inclined, so there is no sense in asking him. He just tells me to figure it out and he will replace any defective part for 1 year warranty. Thanks for your feedback. /forums/images/graemlins/confused.gif

 

[Affordable]

Sounds to me that you are having a problem getting fuel to the injector pump,check the fuel line between the tank and the pump,you have screens in the fuel tank,and in the bolt that attachs the fuel line to the pump.We have also had debris get in behind the valve at the fuel bowl.Remove the 2-small screws holding the valve on,remove it and see if any debis is behind it.It should be a minor fix since the tractor runs OK
at low speeds.

Tommy
Affordable Tractor Sales Co Website & parts

 

[greg_g]

</font><font color="blue" class="small">( I have taken delivery of a new Jinma 404 tractor this week )</font>

Not that it has anything to do with the issue, but I was unaware that Jinma was exporting a 404 to the USA. Or are you located elsewhere? Your forum profile is essentially blank.

At any rate some of the sediment bowls installed on Jinmas have been found to be defective, specifically the fuel shut-off valve. When rotated to what is supposed to be the full open position, the hole inside doesn't mate correctly with the output fitting. Result, permanently reduced fuel flow. Doesn't affect the engine at idle, enough fuel dribbles through to feed the injectors. Not so under load.

Problem is, that it's a messy job to confirm that this is actually the problem. Unless you do it with an empty tank, you're gonna get fuel everywhere while you inspect the alignment of that cut-off valve.

//greg//

 

[JohnS]

While not familiar with the 404 engine and fuel system, this is rather common on the smaller series. Most of it is caused by "special" chinese diesel fuel that is used to test start the engine. I'd start at the pump and go all the way back to the tank. If like the 200 series, there are a number of small inline screens.

 

[Realhyper]

WOW, you guys are awesome. I posted this late last night and woke up early to see lots of answers. Thanks guys. I got this from a guy advertising on ebay in Southern Cali. He was one of these nightmares you hear of. A complete mechanical idiot that should not be assembling tractors or anthing else for that matter. He gave me nothing but the run around after getting my deposit. He told me it was ready and to come pick it up. When I arrived the loader was not on and several other things were wrong. All the bolts he attached were loose, there were no bolts holding the rear lights on, he broke the temp sending unit, missing bolts on the front axles, scratches everywhere, wrong hyro fluid, etc. Now the good news: he was so frustrated with spending a week half baking this thing that I ended up getting it for $6500 with a frontend loader. So a little bologna is worth the savings /forums/images/graemlins/smile.gif I am mechanically inclined having years building hotrods, but I am lost on a diesel, but learning more everyday. I will pull the tank to the fuel transfer pump and repost if I find the answer. The only other problem I have is the tach is not hooked up, with no wires in sight, and the manuel is hard to read on how to hook it up, but I will save that for another post on how to hook it up. thanks again guys. /forums/images/graemlins/cool.gif

 

[greg_g]

The tach sending unit is typically screwed into the side of the bell housing, clicking off revs as the flywheel spins. Voltage is on the tach side, probably a common 12v wire. Ground is the flywheel side. Normal procedure is to adjust "sensitivity" with the engine OFF. Loosen the lock nut, screw in the sensor till you feel it touch the flywheel. Back it off a half turn, and lock down. Start engine, check tach. Fine tune sensor as required.

//greg//

 

[Realhyper]

Thanks for the info on the tach. There are two studs on the back of the tach, but they are not marked. The manuel just shows + and - but not where it is located on the tach. My tractor has the integrated instrument cluster. Any idea which stud it is? I also went over the bellhousing and could not find any sensor to attach to. Is your sensor on the top, bottom, left, right? Thanks for your help.

 

[greg_g]

(+) indicates battery, (-) indicates ground. In this case, the tach sensor should be on the (-) side. Not much help though, with unmarked terminals.

I've never seen a JM404, sorry. But I can tell you where the tach sensor is on 200 series Jinmas. Facing the bell housing from the engine side, it's at three o'clock. Doesn't mean that's where it is on yours though. On my KAMA for example, it's over 10 o'clock.

As I said, yours is the first JM404 I've heard of. But there's a good chance it uses the same tach setup as the JM454. You might have better luck bouncing that question off a few of them.

//greg//

 

[schmalts]

I agree, take off the fuel bowl and make sure you have good flow past the shut off valve into the bowl.. the shut off valve issue has come up many of times. you have a restriction someplace thats for sure. You will find that these diesels are very simple, just a little different than a gas engine but simple.