Injection Timing Help Needed

[GDC]

I finally got my Shenniu 254 tractor back together this weekend(valve job , new head gasket, new injectors, new injection pump, new starter and battery). When i crank it over I'm getting white smoke from the stack but no start. It will start if i spray WD40 down the intake while cranking but it quits after a few seconds. The manual says to adjust the injection timing but offers no procedure. Looking for advice.

Thanks
Greg

 

[greg_g]

Which engine?

greg

 

[GDC]

Greg

Sorry for the delay in responding, between work and computer problems this is the first opportunity I've had. The engine is a 295 and I bought it new back in 1995 from China Diesel (currently Hardy Diesel). I did a search on this site and found references to other brands / engines but not to Shenniu. Are these references still a good place to start?

Thanks
Greg

 

[greg_g]

Well, the manuals that came with my Jinma/KAMA/TaiShan all contained spec and procedure for timing the respective pumps. But unfortunately mine were/are 3 and 4 cylinder engines. If you don't have the engine operations and maintenance manual for your 13 year old tractor, you may have a rough row to hoe here.

Lacking your own manual, best chance would be for another 295 engine owner to jump in here and help. Sorry

//greg//

 

[GDC]

If you don't have the engine operations and maintenance manual for your 13 year old tractor, you may have a rough row to hoe here.

Lacking your own manual, best chance would be for another 295 engine owner to jump in here and help. Sorry

//greg//

I do have the manual, but it doesn't have the procedure for adjusting the IJ pump timing. I'm thinking of marking the timing gear at it's present location and backing off a few degrees to see if I can get it to fire.

Thanks
Greg

 

[doxford jim]

I do have the manual, but it doesn't have the procedure for adjusting the IJ pump timing. I'm thinking of marking the timing gear at it's present location and backing off a few degrees to see if I can get it to fire.

Thanks
Greg

Hi Greg,

It is fairly easy to check the timing on most engines - especially if you have the inline fuel pump.

If you know when you have Top Dead Centre on the engine, you should be able to do it all easily. For TDC you need #1 piston (usually the front cylinder) at top centre, with the valve clearances under both rocker arms.

Once you have TDC, use the graduated markings in the case of the fuel pump where it bolts on to the timing gear casing. These markings will aid you with the timing and are in fact there for that purpose. There should be a long line where the TDC position would be. Try adjusting to around 18 degrees before TDC - that will get you pretty close to what you want. Maybe 15 degrees before would be better. I would guess that the larger groups of lines would be for 10 degrees,with the smaller lines being smaller spacing say 2 degrees or so.

I hope that this makes sense - once you have a look it should all fall into pplace. One thing for sure it is a pretty basic adjustment and there shouldn.t be any real trick to it.

J.

 

[GDC]

Thanks Doxford Jim

I've not messed much with diesels before as far as wrenching goes. So far everything seems pretty simple, but I wanted to make sure I wouldn't screw up the new pump or the pistons by monkeying around in the dark.

Greg

 

[Eagleview]

If the pump has been off , it could be 180* out . You may need to remove it and turn the engine one full revolution , reinstall and follow the steps posted by DJ .

 

[GDC]

I don't believe that it is 180 degrees out as I left the drive gear in place when i pulled the old pump. On this engine, the pump drive gear will not fit through the hole that the IJ pump shaft goes through. Having said that, the pump itself may be out though. It is also possible that the drive gear may have jumped a tooth or so. I will have a go to see what happens.

Thanks
Greg

 

[Eagleview]

That is what i meant , the pump being out 180* . But it is easier most times to pull the pump out of mesh while leaving most things attached and turn the engine over 1 turn to correct (but not in your case as the drive gear may jump a tooth). I think now that you are unsure weather it has jumped a tooth or not you better start from scratch , get your timing gear marks correct and proceed from there . Around 14* for the timing i'd think but check your bible . Do a Google on how to spill time the pump .

 

[psj12]

You can set timing on most injector pump type diesels by removing all the injector fuel lines from the pump. Rotate the engine in the direction of rotation until you see the exhaust valve on #1 cyl close. Continue rotating the engine until top dead center is reached on the flywheel indicator. Now back the engine up (reverse rotation) about 1/4 turn. Put a little fuel into the top opening of #1 injector pump outlet (where you removed the injector line). Wipe off the excess fuel so the puddle on top of the pump outlet is concave. Very slowly using a pry bar on the fly wheel teeth, one tooth at a time, turn the flywheel in the direction of rotation, all the while watching the fuel puddle in the pump. As soon as the puddle moves the slightest amount, from concave to convex, stop and look at the timing marks. If your timing should be 14 degrees BTDC the flywheel marker should read 14. If it does not than most manufactures use slotted holes in the pump mounting flange to allow you to rotate the pump a little to adjust the timing, much like turning old style distributors.. After moving the pump and retightening it the process must be repeated. You can also do the inverse to rough set the timing. That is, set the flywheel to the proper advance mark and very carefully rotate the entire pump in the mounting until the fuel puddle moves. You must then redo the first process for fine tuning.

Should the puddle not move than you are probably 180 degrees out. The easiest remedy is to remove the pump turn the pump shaft 180 and reinsert and try again.

I have used this method hundreds of time and it has always worked well. It will only work on engines with inline or rotary high pressure unit pumps.

 

[Bob Rooks]

Interesting read on spill timing.

Medium/Heavy Duty Truck Engines ... - Google Book Search

 

[greg_g]

Interesting read on spill timing.http://books.google.com/books?id=w3...=book_result&resnum=6&ct=result#PRA2-PA334,M1

Not sure what the technical name is, but I call it drip timing on my old Mercedes. After finding the correct timing mark on the pulley I loosen the pump at it's pivot point. I set the idle at 600rpm, establish the coarse pump setting according to the timing mark, and shut off the engine.

Then there's a little device that temporarily replaces the #1 hardline at the injection pump. It's basically just a threaded compression fitting with a short piece of hardline curved into a 180 degree turn. I then start the engine again, verify the idle is still @600, then rotate the pump till I can time 1 drip per second out of that device. Tighten down pump, remove device, replace #1 hardline, job done.

Not that it has anything to do with timing a Chinese tractor, but I thought drip timing deserved a place right alongside puddle timing.

//greg//

 

[GDC]

Thanks for the info. I'm feeling a lot better about getting this thing going again. Unfortuneatly I won't have time to get back to it until next weekend.

Greg

 

[GDC]

I was finally able to get back to trying to get this tractor started. Between deaths in the family and travel for work, I haven't had a chance to get to it in almost a month!. I pulled the injection pump rotated the engine through on revolution. I reinstalled the injection pump, bled the lines and cranked it over. It fired and ran beautifully for all of 15-20 seconds then quit. I thought there may still be air in the system so cracked the injector fittings and cranked it over with the compression release locked open. Again it fired and ran for a short period of time. I kept this up for almost 5 hrs last Sunday and the best i could get was about 1 minute before it quit. I checked all of the connections for leaks and i have plenty of flow from the fuel tank. Any ideas or suggestions? I'm getting to the point where i am considering pulling the diesel, welding up a frame and putting a Briggs and Stratton on it.

Thanks
Greg

 

[bluechip]

I have seen the supply hose to the primary pump on the injector pump collapse inside. they can flow fine but under the suction of the fuel pump, close of and stop the flow.

 

[Affordable]

There is a check valve on banjo bolt that holds the fuel line to the front of the injector pump,verify that that check valve bolt is in the correct hole.When the pumps come from the factory they put that bolt in the back of the pump just to screw us up I think.If you are looking at the pump there is a fuel line that connects to each side of the pump,if you dont know for sure just switch the bolts (not the lines) so the bolt with the ball check is in the front

Tommy
Affordable Tractor Sales
Home of compact Jinma, Foton, and Koyker Tractors and Parts, Wood Chippers, Backhoes - Affordable Tractor Sales Company

 

[bluechip]

Good call Tommy. I had forgot about the 5 hours we spent trying to get our first jinma pump replacement to work because of that check valve. As I recall, a characteristic of the check valve on the wrong end is the hand pump would get hard after a few strokes. When correct, the hand pump should be able to circulate fuel continuously.

 

[GDC]

Thanks

I am going by memory here, but I remember being confused as the check valve on the new pump was not on the same side as the one on the old pump. I won't be able to get to it again until this weekend, but this will be the first thing I check. Just to be sure that i have it in the right place, it should be located on the exit side of the IJ pump, correct?

Thanks
Greg

 

[GDC]

When I reread Tommy's email i realized he answered my question before i asked it. I can only push the priming pump a few times before it locks up so I believe that this check valvie is my problem.

Thanks again.
Greg