How to time injection pump?

Richard · Nov 3, 2008

We've got an International 444. Current conclusion is that the injection pump has issues. Over the weekend we took it off and my wifes cousin (his tractor) is going to take it to a diesel shop to make sure it's good (or bad) and go accordingly.

It's mounted ... with a slot/pin situation. Meaning, it only goes on one way so it can't be reinstalled out of phase.

My question on timing is...

The pump attaches much like an alternator. It's got three bolts however, one of them is a pivot. The other two connection points are bolts that protrude through a small 'slot' on the pump.

Much like an alternator, you can loosen the bolts and rotate the pump slightly left or slightly right.

Instead of tightening the belt like with an alternator, this will essentially, slightly advance or ****** the fuel delivery.

There is enough gunk on the tractor where on installation I can easily get it back into its original position BUT, how do I know that's the best place for it?

the bear · Nov 3, 2008

there should be a line on the pump it is your timming mark and the block / houseing has a 0 mark and then goes from there to advanve or ****** i uaualy marked the pump to the timming mark which is 0 or slightly advanved depends on which tractor to answer your question yes you can advance or ****** your pump the timming should be very close or your tractor will be hard to start good luck don

fordman6442 · Nov 4, 2008

If it is a Roosa Master pump it should have a small timming window on the side. Small plate about 5/8 x 1 1/2" held on with 2 screws. Take that off and there is a stationary disc with a line on it and also a disc usually with an electric pencil line scribed on it that rotates with the pump. Set your engine timming marks to specs then the slotted holes in the pump body will allow you the final movement to alighn the marks in the window

RWolf · Nov 4, 2008

20 20 hindsight. When I've worked with diesels I always made a mark before I removed the injector pump. That way when I reinstalled it the timing was as it was before. At most all I had to do was a slight tweak.

Good luck

Richard · Nov 6, 2008

I'm going to show you all my ignorance, because I honestly have not a clue if I asked the question properly....OR if anyone answered the question I asked!!

Since this pump has a slot that a pin (on the other mating surface) goes into, there is no way that I can put this back together WITHOUT it being synched with the engine. Now, if I removed the gear (that is still on the tractor) then that's a different issue BUT since that gear is in a housing and all that is intact, my basic timing is ok.

To change my analogy....

Using an distributor for an auto as my analogy.... there is a range that you can rotate the distributor and within this range the engine will run HOWEVER, as you advance the timing (short of detonation) you can eek a bit more performance out of the engine.

This injection pump can be rotated exactly like a distributor can. "gunk" on the entire engine will allow me to replace it EXACTLY where it was (+/- .000000000000001 witdth of a human hair) so I'm 99% comfortable that I can put things back on "as was".

I'm really wondering, should I end up rotating the assembly, how do I know what location is right? (much like how you can use a tac/dwell meter to set timing on car)

Do I want to take the engine to rpm's and then rotate a bit to see if they go up or down? I can't rely on the tach on the machine itself as it's way to bouncy.

Also....it's possible that I'm making too much of this....perhaps I should simply put it back on and then see what happens.

Injection pump is currently at shop, they think they'll have it done next week.

mlauk · Nov 6, 2008

Your chances of the timing being correct are pretty slim unless when you took the injection pump off, the timing mark in the window of the injection pump was lined up and the flywheel timing mark on the tractor was in the correct position. When you get the pump back from the shop the timing mark will be in the window and the shaft should have safety wire on it to keep it in the general location. I would get a manual for your tractor to show the proper way to align the flywheel in the correct position (correct timing mark) before installing the injection pump since the number 1 cylinder needs to be timed properly with the injection pump. I don't know if this makes sense or answers your question, but the main point I'm trying to make is the injection pump will probably be in a different position from when you took it off and when you get it back, so it won't be timed properly to the firing order of the tractor.

Richard · Nov 7, 2008

mlauk said:
Your chances of the timing being correct are pretty slim unless when you took the injection pump off, the timing mark in the window of the injection pump was lined up and the flywheel timing mark on the tractor was in the correct position. When you get the pump back from the shop the timing mark will be in the window and the shaft should have safety wire on it to keep it in the general location. I would get a manual for your tractor to show the proper way to align the flywheel in the correct position (correct timing mark) before installing the injection pump since the number 1 cylinder needs to be timed properly with the injection pump. I don't know if this makes sense or answers your question, but the main point I'm trying to make is the injection pump will probably be in a different position from when you took it off and when you get it back, so it won't be timed properly to the firing order of the tractor.

I appreciate your comments and hope my ignorance doesn't frustrate you (or anyone)

but...

I guess I'm missing something then. I do not see how I can possibly put this pump on in any way other than how it came off.

I guess another way of putting it, like a gear that has a keyway (or what ever the little "block" on the shaft is called that fits into a slot on the gear.... this can only go on one way.

hmm.... you've got me thinking now....

question...

Once the pump is off the machine and in my hand, is it possible that the pump can be off by 180 degrees? (or 360?....I don't know)

Anyways.... I'm presuming that the round nose on the pump turns 1:1 with the drive on the tractor. That's a given because of how its designed.

HOWEVER.... I suppose it's possible that 1 rotation of the tractor gear might NOT be 1 rotation of the internal gears of the pump....in other words, much like a crank verses camshaft, maybe the nose of the pump has to turn twice, to get one turn of the internals of the pump?

crimeny....I'm confusing myself trying to put this into type.

If the INTERNALS of the pump are geared 1:1 with the drive input of the pump and if the drive input of the pump is geared 1:1 with the drive gear (that is connected to tractor) then I fail to see how it can go back in any way other than how it was disassembled.

a) did that make sense?
b) if not, anyone care to (try) to articulate what I seem to be confused on? (I won't get upset)

mlauk · Nov 7, 2008

The injection pump usually runs off the camshaft just like a distributor on a gas engine, so your timing can be off 180 deg. When I reinstalled mine, I had to take the valve cover off to determine the fire at the number 1 cylinder so I wouldn't be off 180 deg.

Richard · Nov 7, 2008

ok, so if the pump can be off 180 degrees, (even though it's mounted on the same keyway) I can understand that.

My next (and hopefully last) dummy question is...

If the pump is installed off 180 degrees and we try to start the engine....

Is there any possiblity of damaging anything or will we simply have an engine that won't start?

If we have a danger of damaging something, then what would that be?

RobJ · Nov 7, 2008

Ok no no chance of damaging anything.
I'm not familiar with the 444 but the basics are the same.

When you pulled the pump maybe there was a slot or key or something in the driving gear. If there is a keyway, you can't get it out 180 (as long as you did NOT rotate the engine..PERIOD!!). If there is a slot, like on my BIL's JD350 crawler, you have a 50/50 shot. If it doesn't crank after bleeding...guess what.

To check the timing you first need the specs. Can't help you there. Then look at some inspection covers on the flywheel for markings. Sometimes they are on the front pulley. On the front you might see 2, TDC and the begin injection mark. there are various ways to set it without any of the above. First you still need the timing specs.

Lets say it's 20 degrees and we want to use the front pulley. Google finding TDC. one easy way is to pull the injector and drop a long stick, etc and have it touch the top of the piston. When it stops going up and is not going down...you have TDC. If both valves are rocking, you are on the overlay TDC stroke, turn the engine over 360 degrees and then you are on the TDC compression stroke. All this is usually done on Cylinder #1. When you find that position, mark it on the front pulley. Of course mark it with some stationary mark on the front cover. Now ssome math...measure the diameter of the pulley * 3.14, divided by 360. This will give you the measurement of each degree on the pulley. I use to use a metric tape and go down to milimeters. Then multiply this number by 20(timing). Since the front pulley that connects to the crank turns clockwise, take this measurement and measure along the outside of the pulley to the right of the TDC mark. Fuel should begin moving at this point. Then to measure when the fuel begins to flow, you need to rig up some sort of clear hose where you can watch for this movement. Then get it all staged and turn the engine over slowly and watch for fuel moment.

Since the injection pump turns at half the rotation of the engine (IE pump does a 360 and the engine does a 720), the pump is usually driven off an idler gear (mostly for more room in the front cover). So the pump should turn the same direction as the front pulley. In you need to advance the timing, turn the pump counterclockwise. ******, clockwise.

I'm making some assumptions here on the 444, but the basics are the same. Its a lot easier if you have some marks already. On my L they are on the flywheel. I think I have a pic...

Ah yes...a link with some pics from a while back..

http://www.tractorbynet.com/forums/parts-repairs/94913-checking-timing-kubota-l2500.html

Good Luck,
rob