Adjust injector pump?

[humblesmith]

We just rebuilt the 276 diesel engine on my 2640 tractor. We were very careful with everything and replaced anything that appeared to need replacing.

We did not do anything with the injector pump other than to make sure it was installed correctly.

We just started the engine after a complete rebuild. It started well. It blew white smoke for a few minutes, then the rings sealed and the exhaust cleared up. We ran it for about 45 minutes, then left it for a couple of days.

Today when we started it again, it started well......ran white smoke for a few short minutes, then the exhaust cleared up well to almost clear. After about 25 minutes, it suddenly started to show white smoke and the idle dropped. We ran it for another hour and a half, and the smoke was a bit intermittent at first, then it settled in as a steady cloud of white smoke that did not go away.

We are thinking it is unburned diesel and possibly the engine is running too rich. Is there a way to adjust the injector pump to balance the fuel/air mixture?

Does anyone have any other ideas?

 

[Bob]

Run the *&^*$ thing, pull it, warm it up, then post back.

"Is there a way to adjust the injector pump to balance the fuel/air mixture?"

That doesn't happen with diesels. more fuel = more speed/power, etc..

 

[Al Baker(pumpman)]

You have a pump where One set of plungers is making fuel for all cylinders. So if one hole gets X amount of fuel so does each other. Only way one can get to much, or not enough, or maybe out of time with each other is if you have a nozzle stuck open, or closed. In Your case you may have a nozzle stuck open, or a engine valve leaking compression. Either set to tight, or not seating. Dont mess with your pump. Al

 

[FBH44]

YOu say you ran it for 45 minutes, then 25 minutes. Did you just let it idle along, lope along, real gentle, or did you rev it up some? My Perkins diesel manual says to NOT just let her lope along, idle along, but warm it up at 1200 RPM for a few minutes. Then operate at 1700 RPM. When I started doing that, she stopped smoking, stopped blubbering , ran perfectly. I'd say rev 'er up!

 

[Dieseltech]

White smoke means fuel is getting to the chamber, but there's not enough heat to burn it. How deep are the valves recessed in the cylinder head? If too much that kills compression heat needed for starting, MUCH more critical on diesel engines than gas. Just had the head repaired on the 4-78 White forklift I have for starting trouble, all the valves were .010-.050 below flush. They needed to be ABOVE on that engine, had all twelve seats installed to get them back where they needed to be for best cold starting, and now starts as it should.

 

[buickanddeere]

Has a cylinder lost compression? Were the cam followers returned to thr same cam lobes? Was the cam reground and the followers trued up? Valve spring pressure checked?
As previously asked. Was this " running" under moderate to heavy load witb the coolant at 180F or higher or just putting around and idling?
What is the engine oil?
Were the sleeves, rings and pistons all replaced?

 

[Tramway Guy]

Also check for air restriction going in.,..blocked air intake will
do exactly what you describe.

 

[thepumpguysc]

You could loosen an injector line one at a time to see if the smoke cleared up on a particular cylinder, just to narrow it down..
If they ALL stayed the same.. look further into the engine.

 

[DONMYEIL]

Sounds like the injector pump is 180* out of time. One other thing , but if the pump wasn't touched should not be the problem. That's adjusting the speed advance . You need a special timing window to do that . This is assuming the pump was correctly timed to top dead center .

 

[Tx Jim]

(quoted from post at 13:02:06 12/12/16) Sounds like the injector pump is 180* out of time. .

I thought a diesel engine wouldn't start running if inj pump was 180° out of time. I guess one is never too old to learn something NEW.

 

[humblesmith]

So far, we have run this engine for a little over two hours after the rebuild. We ran it at about 1200 rpm for a very few minutes, then spent the next two-plus hours at 1500 to 1700 rpm, partly just driving around or and partly idling. Occasionally we'd rev it to 1900 or drop to 1200 for a few seconds.

Again, after the initial few minutes to seat the rings, the exhaust cleared up to almost clear. We drove it around and had no issues. Then we ran out of daylight. Came back another day, it started and smoked for about a minute, then cleared up for 25 minutes or so. Then it suddenly turned white and stayed that way.

There is no coolant in the oil or oil in the coolant. The exhaust smells like deisel.

We have no reason to believe that any one cylinder is acting different han the others.

The cam followers were returned to the same cam lobes.

The cam was reground and the followers trued up.

The machine shop tested the valve springs and replaced the flattened ones.

I gave no special instructions to the machine shop on the valve height. They did it according to whatever engine specs they looked up.

The sleeves, rings, and pistons were all replaced.

It would seem to me that if it were a compression issue due to the valve height, then whatever compression issue would have been there from the first. Instead, this engine seemed to change after a little more than an hour after the rings seated. RPM was kept up about 1600.

Before disassembly, all the gears on the front of the engine were carefully marked and returned to their same positions.

This tractor has a Roosa Master injector pump, with a couple of the adjuster screws wired down to prevent adjusting.
Questions:
Have you guys seen much trouble with these pumps?
Is there any reason to think the pump would change after warmup?
Other than make sure it was installed back correctly, we did nothing with this pump. When we put a listening device to the intake of the pump, we can hear what sounds like a mild mechanical ticking. We assumed this was normal. The pump is definitely pumping, for the engine runs....it just seems like there's fuel that is not getting burned completly.

Thanks for all the help.

 

[humblesmith]

Sorry, the cam followers were returned to the same same cam lobes, the the cam was NOT reground or machined.

 

[Mike M]

Were the injectors ever tested during this process ?

 

[humblesmith]

(quoted from post at 13:34:12 12/12/16) Were the injectors ever tested during this process ?

We did not test the injectors, but replaced them all. They are all brand new.

 

[Mike M]

I rebuilt a 2840 engine one time. Thing blew white smoke really bad when cold. Really had me worried. Those have a different inj. pump. Luckily I talked with my pump shop man and he said ones like mine wear inside a bit and then the timing gets off. He told me which way to turn it. Too bad I forget but it was only like 1/2 a line or a full line at most ? and it made all the difference in the world ! So I wonder if perhaps your timing is off ?

 

[centash]

Put it to work. I don't think the rings would seal in a few minutes. Partial to full
loading is a better way to break it in. Ben

 

[tomstractorsandtoys]

I did not think so either untill this fall when I put one 180 out on a 329 engine on a 95 combine.It ran but just so, lots of white smoke. I knew I had a problem so we put it into the shop and pulled the timing cover. On a 95 combine you have to install the pump thru a little hole in the grain tank,next time I think it would be easier to just pull the engine. Tom

 

[tomstractorsandtoys]

Operating a tractor with no load will not set the rings in. It just makes things gum up with oil. I learned this on a 4020 earlier this year. Put a good break in oil in it and put it on a dyno for a few hours like the service manual says or just work it at about 3/4 load. Tom

 

[humblesmith]

So would it be a proper load if I just hooked up the brush hog and did some mowing?

 

[JD Seller]

You need to load the engine to seat the rings. Running it with a light load or idling it will soon make the rings never seat. It will smoke an use oil until the rings are replaced again. You either need to be doing some field work or use a Dynometer to pull the tractor.

I have seen this happen on tractors that where overhauled in the fall or early winter. Then the owner would run it lightly feeding hay and such over the winter. Never really working the tractor. About 75% of these tractors never quit smoking and using oil even when worked hard later. New piston rings have sharp edges. These wear/cut the cylinder bores to match each other. If you run it too long with out much load the rings lose the sharp edge and never will seat to the sleeves.

Also use break in oil. A real good oil right at the start will cause the same issue as low loads.