Planning on getting a new IP very soon and wondering how to line my old pump gear up with the housing so i can have my new pump atleast somewhat static timed, like maybe mark the dowel pin in relation to the housing would that work or is there a rule of thumb somewhere in a write up?.. Thanks for any help!!

 

Eallend,

It won't matter where your dowel in the pump gear is situated. The important part is, don't remove the pump gear housing! There is either a plate on the front of the pump gear cover (around 87 & up) or you remove your oil filler tube (most 6.9's) to expose three 12 point bolts which hold the pump to the gear. Just align the pump dowel with the hole in the pump gear, and align the mark in the top of the pump with the line in the top of the gear housing. This is "static timing" this is a starting point where you can get the truck running and up to normal operating temp to make timing adjustments. If you are timing by ear, getting it close is all that you can hope for. As a rule of thumb, what you want is a healthy top end rattle, with no bottom end knock. Too quiet is too retarded, bottom end knock is too advanced. Rotate the top of the pump to the passengers side fender to advance the timing, towards the drivers side fender to retard it, from there you need to use the butt dyno! Your best bet is to either buy, or find someone with the proper equipment, to time it right though.

Good luck,

Mac.

 

Okay. that being said.
In another post of mine about my water pump, i showed how i marked my pump before removing it to do my timing cover.
BEFORE taking the pump off, i took it off still attatched to the pump cover or housing., oil filler basically, i took the actual filler tube off, and wiped the face of the gear off where i could s ee, and marked it on the pump in relation to the housing, that would work yes?

Your saying for my new pump, leave the cover on, unbolt my old pump from the rear and pull it out the back, and when i get my new pump, allign the dowel ON The pump gear, to a hole on the pump gear COVER? That confused me, cause theres only a dowel ON the pump gear, and you can't allign a dowel on a gear with a hole on the same gear. that confused me.
i know on my model, 86 6.9l, when you pull the oil filler tube off, theres a machined hole above the left bolt hole and a machined hole below the right bolt hole.
soooo? i'm confused

 

Go look at that picture in your water pump thread. There are 3 bolts that hold the pump to the gear. At about 11 o'clock in the picture you can see the dowel. The dowel is attached to the gear, and sticks out both sides. There is a notch on the injection pump that fits the dowel to line it up with the gear.

What you did was good to remove the pump with the housing, and replace it without changing the timing. Idiots remove the pump and housing, then bolt the gear to the new pump and put it on. That screws up the gear train timing, and thus the pump timing.

To change the pump, you want to leave the gear in place, so the gear doesn't get out of time with the other gears. There should be a line scratched into the back of the gear cover and the front of the pump housing. That line is to get the pump roughly static timed so the truck will start. Then you use a timing meter to tune it in by rotating the pump against the housing (the gear is always aligned the same to the pump, thats what the dowel is for).

Does that make more sense?

 

To answer that question, if you could mark the IP drive gear and the next gear below (camshaft drive gear) so you knew exactly how they meshed to each other than yea theoretically you could re-install it the same way. If you took the housing off, you'd discover a problem, in that the gears mesh below where you can see, so you can't mark them. (there is a technique mentioned using a butter knife as a tiny mirror to spot the factory timing marks from above, for worst-case-scenarios)

What we're saying is, if you're replacing the IP, don't remove the housing at all!
WRT the photo below, if you don't remove the housing (red arrow) the IP drive gear can't move and thus can't become un-timed. Remove the 12-point bolts (blue arrow) and the three on the back of the housing (housing-to-pump, NOT the two that hold the housing to the engine!) and pull the old IP out. When you install the new IP, the dowel (green arrow) will ensure the IP goes back in the same orientation to the drive gear. Thus, gear-wise, the timing is the same.



You still have to rotate the pump relative to the housing in small increments to achieve static timing. Start where it was before (make a mark on the housing where it meets the mark machined into the pump) to get it started and work from there.

 

Woops, dual post, cheers tecgod!

 

So what i need to do is KEEP my gear, unbolt the ip from the gear, leave my gear where its at, and just slide my new pump in there and fit the dowel pin in my gear and ill be good to go yeah? Atleast until i can dynamic time it. Thanks for all the explanations guys makes sense now,

 

You got it! There's not enough room in the housing to move the gear accidentally that way.

Good luck with the swap.

 

Right on.
Thanks fellas! ill let you know how it goes!

 

Exactly right, unbolt the three 5/16 12-point bolts and leave the gear in place. I did mine just as this process, lined up the new pump to the dowel on timing gear. Line up the top scratch line and it should start, after cranking a bunch to get it full of fuel of course. Once started and warmed up, get it timed, either by instrument or by ear/feel. An IDI will rattle pretty good when timed correctly, especially at idle. It smooths out when higher speed. Should not knock, but a healthy rattle form the diesel combustion is OK.

The job is not hard, but just pay attention and you will do fine. It will take some time and you should do a return line kit while you have it apart. Also good time to replace the injectors and glow plugs while it is all apart.

I am good at spending your money......

 

I'm in the process of replacing my IJ and I needed much of the info given here. THANKS!! I'll let you know how it turns out. - Don