j.fonder

ok, so I'm replacing my injection pump with a used one and i have a question on timing. the "new" injection pump is locked but i'm assuming its not locked in at TDC. So what i've read when replacing a pump that is in known TDC is this

1. remove old pump
2. rotate engine to TDC
3. install pump at TDC

in my case, can i just rotate the pump gear until the keyway lines up with the keyway in the pump shaft? or will my timing be off?

i know the BEST thing to do would be to take the pump to a shop and have them set it to TDC and then install with motor at TDC. just trying to figure out if this is required.

j_martin

With the caveat that the gears are in time and haven't skipped a tooth or so, when the pump is lined up on the slot, it's in time.

I would think it'd be safer to rotate the pump than the engine with the pump out.

j.fonder

It has been skipped a tooth. So I can just unlock and spin the pump shaft to line up with the keyway in the gear?

edwinsmith

Where did you get the pump? Have you checked with them to see if it was locked at TDC? When I replaced my pump it was locked at TDC with the key pointing down at about 5:30 position.

Assuming the pump is locked at TDC then you get a barring tool and hand crank the engine until the timing pin just goes into the gear. Then pull the pin out.The keyway should be at the 5:30 position. Then you install the pump and partially tighten the nut on the shaft. Then you rotate the pump slightly to take up the gear lash and tighten down the 3 mounting nuts. Then tighten the shaft nut to the torque spec. and reassemble everything else.

If you do it some other way the timing will be off and you'll need to take it to a diesel mechanic to have the timing set with a dial gauge.

There is a Dodge film in 3 parts on this forum somewhere that outlines the entire proceedure with torque specs and everything. If you can't find it then PM me and I'll email it to you or find some other way to send it.

Edwin

j.fonder

It's not at TDC and I've watched those 3 videos, which is what led me to ask the question when I saw the keyway in the shaft was at about the 1-2 o clock position. I've had one on and off before but it was the same pump so I just replaced it the same way I removed it. This is an entirely different pump with unknown timing. So guess I'll play it safe and get it timed tomorrow if I can/have to.

j_martin

If the gear is right, it's pretty hard to get the pump off except for the final setting (slots) before you clamp it down, turning either the engine or the pump to line up. If you take a pump off known to be in time, you mark the pump and timing case so you can put it back extremely close to what it was. If you replace the pump, you have to time it with a dial indicator inserted in the timing port in the middle of the distributor section, and then mark it.

If you know what it's supposed to sound like, you can get real close by ear. I used to time VW's by ear. First one I paid to have it checked. It was dead on.

Most of us overspeed the engine and over advance the pump anyway.

bannerd

If the plunger inside the pump hasn't been messed with... take the timing cover off of the motor and make sure all the timing marks are lined up and then line the pump gear to the rest of the timing marks.

Look at the front of the pump, you'll see an index mark on the seal. Take note there is also a round tab that should match that index mark on the seal.

This is reference that the pump is at TDC and is set to cylinder #1 On the back of the pump where the high pressure lines go into the pump, take note that there is stamped numbers (A,B,C,D,E,F) Each number represents a cylinder firing order. In this case each line goes to the segmented cylinder;

D=1
E=5
F=3
A=6
B=2
C=4

If the index mark on the seal and the tab all line up to cylinder 6 AND you put the timing gear on and it lines up with the timing on the motor then you're good to go. If you set the pump to TDC and the index shaft does not match the timing on the engine, STOP. The pump needs to be calibrated with a dial guage and get timing to the rollers inside the pump.

You you can take pictures of the front of the pump I can muck up the pictures with the references. Although it should be really obvious.