Best Injectors

[Power Wagon]

Originally posted by DJP

Power Wagon,



I never did time my injector pump the last time I installed it, after the pump was overhauled. I used the TDC plunger and aligned the marks on the pump housing to the pump mount pad. I realize this is a shade tree mechanic way of installing an injector pump, but it runs well and I'm seeing the 22 MPG (empty) that Matt S has attested to with the Lucas injectors. I realize I am probably not seeing the full benefit of the potential performance available with the 'Ol Blue specials since I never timed the pump. I would like to purchase the equipment necessary to time the injector pump, and locate true TDC. Do you have any tips for me on where to purchase the equipment? Can a dial indicator be adapted to work as a timing tool? Any informatiom you can give me on this is greatly appreciated.

Heh... One of the things I've often heard, is that "if it ain't broke, why you try'in ta fix it?" line. I'm often somewhat at a loss as to how to advise someone in your situation. Your truck runs well, and produces economy that, well... Is at least as good as average, and you say it runs good, so what's to say it needs help?



Let me describe the process, what kind of tools it takes, and then perhaps you'll be better equipped to determine if you really want to go through it.



The VE pump is timed by measuring injection plunger stroke. On the test stand, when your pump was rebuilt, the amount of distance between the bottom of the plunger stroke and the point where the pumping ports close in the head is supposed to be set to a rather precise amount. Since it is done with spacers, it does have a small tolerance, and in fact, it's usually done before you get to the test stand, but that's another story. Of course, if you had a lousy job done, it might not be right, in which case, every procedure after that is doomed to failure. (the words "Cummins ReCon" resonate in my mind for some mysterious reason at this point... Like a faded bad memory from my recent past... )



On the technician's bench, the pump is rotated until it is at the #1 pumping position. Then, an adapter is screwed in where the plug in the center between the outlets is now, and the total movement of the plunger is measured on a dial indicator. First, you move the pump driveshaft back and forth to find the absolute bottom of the stroke, and then slowly rotated in the "run" rotation until the spec is reached, be that 1. 2MM, 1. 4MM, or whatever. At this point, a lock bolt is tightened against the driveshaft to prevent it's rotation until you loosen the lock at install time. As you see, the higher the number, the more the pump is advanced in relation to the crank. The engine is then spotted at true TDC (using the stop pin, measuring piston movement with a measuring device down the injector hole, or even by pushing a valve down agains the piston to show it's maximum upward movement. At this point, the pump is bolted to the gear that drives it, the nuts that hold it in place are spun up to almost snug, and then the pump twisted to remove all the slack in the drive gears. Then, it's tightened at the mounting nuts (three) while tensioned to prevent slack in the gears from spoiling your timing.



To do this on the engine, you must find TDC, you almost certainly have to remove the injection lines and the linkage mounting brackets. Once true TDC is found and marked so it is repeatable, you take out the plug on the end of the pump, put in the adapter device and a spring loaded dial indicator in the adapter. You then rotate the engine backwards to the point where the dial indicator shows the plunger has reached bottom and back and forth to locate the 0 point where you zero your dial indicator. Then, you move the engine forward until you hit TDC, whereupon you read the dial indicator to show if you are ahead or behind. If you are off, you then loosen the pump mounting bolts and twist it slightly to get the dial indicator right.



This IS somewhat complex. And, if you don't understand what you are doing, you'll never make any progress in the effort. But what's more, the adapter and dial indicator are not cheap. While I actually don't know the official price for the adapter, i'm sure it's between $50 and $150, and easily another $40 to $100 for the spring loaded dial indicator. You t hen need a new copper gasket for the plug and an inch pount torque wrench to get it right. It's pretty picky, actually...



Now, if I owned a truck, I would not mind buying the tools to time it, and passing them around, but it seems like a rather large investment for an owner to make, usually for a one-time shot. You'll only need to do this again if your pump is rebuilt, gears changed on the engine, or for some reason, you think you were off. You can mark the housings (gear and pump) and putting them back in line with a sharp scored line is more than adequate.



On the other hand, it's a 2 to 3 hour job at a shop, and that's 100 to 175 dollar job. It's BEST done at the point where your pump gets worked on, and the extra labor involved to do it "right" is really not much.



Well, I don't know if I cleared or muddied the water for you, but hopefully this will give you a better idea of whether or not you want to try this one at home

 

[drives mopars]

cost to advance?$$

whats a shop to charge to advance timing?



i was going to call imler ? diesel in sacramento



bill

 

[drives mopars]

got it

pw i read it all now thanks

 

[Mel Fuelling]

PW,

I don't own a barring tool, and in the interest of field expedience

(the shade of the tree that I have available), I recently found that

I could accurately and easily control crankshaft rotation and position for verifying TDC(my timing pin happened to be dead on)

and checking & adjusting injection pump timing by: 1. Removing Fan

2. One wrench on alternator(going counterclockwise)

3. Second wrench on crankshaft(clockwise)



All dial indicator readings need to be taken after engine is backed up sufficiently to remove all timing gear lash.



This seems to offer sufficient crankshaft control to make it much

easier to push the timing pin in if you haven't already found and

marked TDC on the H balancer. By the way, do Cummins H balancer outer shells ever slip like some gas engines do?

 

[Power Wagon]

Originally posted by Mel Fuelling

PW,

I don't own a barring tool, and in the interest of field expedience

(the shade of the tree that I have available), I recently found that

I could accurately and easily control crankshaft rotation and position for verifying TDC(my timing pin happened to be dead on)

and checking & adjusting injection pump timing by: 1. Removing Fan

2. One wrench on alternator(going counterclockwise)

3. Second wrench on crankshaft(clockwise)



All dial indicator readings need to be taken after engine is backed up sufficiently to remove all timing gear lash.



This seems to offer sufficient crankshaft control to make it much

easier to push the timing pin in if you haven't already found and

marked TDC on the H balancer. By the way, do Cummins H balancer outer shells ever slip like some gas engines do?

Weeeeelllll... That's how I did it, except I left the fan on. It's a pain to deal with, but seems to be faster to not mess with it.



the pump itself tends to rotate when it's not locked, against rotation which takes up the slack generally. When it's locked, that's an issue to deal with.