What? Read all about what it is here.
Cliff notes version: You are not timing or changing the timing of anything. Well, not as most people refer to timing on engines anyway. What you are doing is changing the relationship of the CP3's plunger stroke to the engine's piston stroke. You will not change injector timing by doing this. The injectors are not timed by the CP3. The CP3 just feeds fuel to the rail, and it will happily do it with its plungers in any relation to the engine's pistons. Actually, it's that relationship that causes the noise. I do not know what situation in that relationship causes the noise but in certain circumstances, the noise occurs...
And this is how I fixed it...
First thing you're going to want to do is make sure that the noise you have is the CP3 and not an injector or something. The sound is comparable to marbles being tapped on your windshield. The noise is loudest around the CP3 pump. It is more of a repetitive "knock" than a "tick".
Now that you're sure that you have the controversial CP3 knock, grab a friend, some tools, and some beer. Just about anyone can do this. I had never touched a CP3 before doing mine, though you'll want to make sure either you or your friend has at least a little mechanical aptitude.
1) 1/2" drive breaker bar
2) 3/8" drive ratchet
3) 27mm socket
4) Barring tool
5) Harmonic balancer puller (or similar, see below for part # at Autozone.) Here is a link to another puller made to work specifically with the Bosch injection pumps.
Autozone Parts (These are only needed if you are using the Autozone puller. If you are not, then you can skip these parts)
1) Part # 27019 - OEM Harmonic Balancer Puller. This is one of tools you can rent and keep it if you decide to. The guy told me I could cut the bolt and return it, no questions asked I'm not sure if this was just a disgruntled Autozone employee or if this flies everywhere, but I opted to pay the 15 dollars to "rent" the puller. Later I opted to keep it.
2) Part # 780-445 - M8 - 1.25 x 45mm Hex Head Cap Screws comes with two
3) Part # 766-012 - Flat washers to fit the above bolts. I used 3/8". They were a little big but they worked. I just doubled them up.
Harmonic Balancer Puller Modification:
If you are using the Autozone Harmonic Balancer Puller (Part# 27019), then read this section, if not, skip to the next section ("The Fun Stuff").
Screw 6-3/4" long bolt in puller kit into yoke (This will allow you to clean the threads after cutting).
Cut 3-1/4" off of bolt (Notice which end was cut in the picture below).
File yoke on both sides (see pic below) so that the bolts will line up with the bolt holes in the CP3 gear. It won't take much. Just enough to take off the ridges.
The fun stuff:
Locate belt tensioner
Insert 1/2" drive breaker bar into square hole in tensioner
Push bar clockwise to relieve belt tension
Take belt off PS pulley
Locate plastic access cover on timing cover in front of CP3
Clean around it
Insert 3/8" drive ratchet into square hole in cover
Break plastic cover loose and remove
Don't let dirt into your timing cover (Yes I did a terrible job cleaning mine, this is an example of "what not to do"
Locate nut on CP3 shaft
Use 27mm socket to remove nut and washer
Don't drop these inside!
Put your puller together like this:
Set puller up on gear with convex side facing the front of the CP3
Screw bolts into holes in the gear
Turn big bolt in the middle of the puller to pop gear loose
Mark crank pulley
Locate flywheel access cover and remove it (it's right next to the down pipe)
Insert barring tool
Bar engine 60*. We're just eyeballing it here. This isn't something that has to be exact as this process does not affect timing. Seems like a couple people went 30* the first time and then had to go back and redo it. As far as I know, 60* has worked the first time for most.
22) REMOVE BARRING TOOL!
<-- Pretty Important
Reinstall CP3 nut and washer, torque to 77 ft. lbs.
Reinstall plastic access cover. Don't over tighten, it just needs to be snug.
Reinstall belt ensuring that it is seated correctly on all pulleys
Remove breaker bar from tensioner
Start truck. If noise is gone, go to #28, if not, repeat #1-27.
Reinstall flywheel access cover
Feedback and questions welcome!