When reinstalling inj. pump is locking pin necessary?
 

I've been going over the FSM procedures for injection pump removal because my gasket there is leaking and lately it has gotten worse. I also plan on replacing the oil cooler lines while I'm at this job.

Studying the procedure for inj. pump removal and replacement, the FSM contains two separate procedures for replacement, one that includes using the locking pin and one that simply requires the engine to be set to 24-deg bef. TDC and the pump installed with the driver and pump-shaft marks aligned. The locking pin method requires the marks to be aligned with driver four degrees aft and engine timing set to 15-deg after TDC.

I can't really discern any noticeable advantage between the former and the latter method given the start of delivery must likely be advanced or retarded after delivery anyway.

Then again, I was wondering ...

Is it possible to avoid having to adjust start of delivery, given the delivery is already aptly timed, by using the locking pin to lock the current start of delivery in place prior to pump removal? Is it even possible to insert the locking pin before removal of pump (seems like an extremely tight fit to get the thing between the block and the pump)?

Was wondering what everyone's thoughts were on this, and why the FSM calls for a specifically different timing set when using the pin.

yes. It helps keep the pump and engine timed.

but if you feel confident in doing the method without the pump lock have at it.

I've done it both ways. Obviously, with the pin is easier but both procedures work.

Why is the engine set to different timing specs when using the pin? ... Also, how hard is it to keep the spline on the pump from moving when inserting it back into the block? A two-man job?

The pin does not lock the IP at start-of-delivery. The SOD remains the same regardless of installation option chosen.

Does your IP even have the option of using the lock?


Not hard at all. It doesn't have to be perfect; you still need to fine tune the IP position by one of the available timing methods.

PNP Tomorrow
 

Going to STL tomorrow for some errands, gonna stop by the PNP there. They got listed an 88 300E and 86 300? ... both have copper injection lines, I believe, so I'm hoping to get a line off one of them and cut my own drip tool.

I imagine the compression fittings on the gasser and diesel injectors are all the same size and would work for a drip tool on an OM617?

... hmmm I don't think the gasser lines are the same size... they flow fuel at a much higher volume, and MUCH lower pressure.

as for your 83 having the lock pin feature... I don't believe is does. I think 85 was the first year with it.
I've swapped IP's by setting TDC on the CAMSHAFT and setting the timing from there. no big deal.

Why would you do that?

it's a simple location to verify timing of both devices.
it's just where I pull stuff when I don't have time to do it right.

I don't have a locking pin anyway, so that's exactly what I was planning on doing. I figure if I rotate the engine to 24-degrees BTDC before removing the injection pump, I can note where the timing is on the pump during the removal to see if it's far off one way or the other.

VS ... How certain are you about the gassers injection size? Not a 13-mm compression nut? If the gauge of the line is indeed bigger than the diesel, how much of a difference would that make for a simple drip test?

That won't tell you anything. If you really want to know where your timing is, do a drip test before you remove the IP. All you need to do is rotate the crankshaft slowly until you get the drip, then read the angle on the balancer. If you have never done the drip method, doing it beforehand will give you a little insight into the sequence of events; most folks find the test a bit counterintuitive.

Drip test procedure
 

Qwerty ... that's what I'll do then. A bit of practice. Either way ... questions:

i'm wanting to do this job Friday because my neighbor offered to help me and he has a lot of mechanical experience and a great garage with every tool imaginable. I'm concerned about not being able to find a drip tool before then. if i can't get something cut from injector lines at the PNP, I've read about the "well up" method of timing where you watch for fuel to emerge in the number one injector port, but this doesn't seem as accurate to me as the drip method. I've also read about using the number one injector hard line itself as a pseudo-drip-tool in a glass of water, watching for bubbles at the rate of one per second. Both of these methods sound jankity. What's everyone's opinion on this?

For most people who have been wrenching a while, who have a good understanding of the 4 stroke principles and other principles, including good workshop practices, most jobs are relatively simple once you get into it, even jobs youve never attempted. As we know, simply placing the crankshaft pulley on the correct timing mark is meaningless, if #1 cylinder is not on its compression stroke. Pulling the rocker cover is one of the simpler ways to make that determination, noting both the cam lobes for #1 are off the valves pointing upwards at generally opposing angles from each other.

In that position, if at all possible to remove the timing plug, you could note the position of the indicator inside the pump.

If you put it back together the same way you took it apart, it will run. Well, it will run if it ran before you took it apart anyway. Its when people forget to note the proper positions of parts before removal, or dont know what the heck they are doing to begin with, where they get into trouble.

That is NOT to say you shouldn't do a proper injection timing check after reassembly, because you always should. But if the marks are properly aligned to the notes you made beforehand, it will run.

This is an excellent example of properly noting positions before ripping things apart. Learning how things work can never be a bad thing. And, if your going to do the drip test afterwards, doing it beforehand isnt really adding anymore labor to the job.

On the 617 engine, removing the oil filler cap is all that is necessary to view the relevant cam lobes. It doesn't get much simpler than that.