CRD Injector pump update. Gonna have to sell the CRD :(

gmctd · **Posted:** Tue Jan 11, 2011 10:08 am

Right, I've seen that - to be honest, I have not disassembled the KJ drive sprocket from the CP3, so it is possible that Bosch keyed the sprocket and drive shaft due to the 4cyl stresses resulting from the 2-per-rev firing pulses - you can see one result of those extreme stresses by observing the blowby pulses with the oil filler cap removed

But, nah!!!!!! They would have consulted with me, first, B4 they did that..........right?

kapalczynski · **Posted:** Thu Jan 13, 2011 4:13 pm

gmctd wrote:

Seems plausible on I6 or V6, where three cyls fire per 360deg crank revolution, once each 120deg - CP3 has three pumping pulses per 360deg revolution, one each 120deg - CP3 rotates once per each crank revolution - 4cyl fires twice per 360deg revolution, first cyl at 0deg, second cyl at 180deg, or once each 180deg - CP3 would give one pulse at 0g, engine fires at 0deg - CP3 gives second pulse at 120deg - engine fires 60deg later at 180deg - CP3 gives third pulse at 240deg - engine fires third cyl 60deg later at 0deg - etc - similar dis-timing with V8, with 4 firing events per 360deg - IIRC, having not looked into this for nearly a year (and my write-up has myseriously been deleted, prolly by a gasser modulator!), the CP3 input\drive shaft is tapered, as is the drive gear, for simple interference fit when nut is torqued to proper value, not requiring a key\keyway

What say you?

And, don't fergit: I know just enuff to be dangerous, eh..............

Glad to hear from you, MMo

May be off base here, but I think the pump sprocket is sized exactly so that the difference between the crank rotation and the pump sprocket allows it to always be at the top of a cycle. 3 pump rotations times 4 cyl = 12, so if the gear circumference was as such to do 1 pump rotation (3 pump cycles) per injection cycle (12 pumps per engine/crank rotation for example) it would be timed at the top of the cycle at the same time, EVERY single time for each cylinder. It is doubtful they would put a timing mark on the pump sprocket and say it needed to be lined up if it didn't matter so I think MrMopar is right.

Remember, injection is only done once per 2 revolutions of crank per cylinder due to exhaust part of combustion cycle.

- Mark

Joe Romas · **Posted:** Thu Jan 13, 2011 5:17 pm

kapalczynski wrote:

May be off base here, but I think the pump sprocket is sized exactly so that the difference between the crank rotation and the pump sprocket allows it to always be at the top of a cycle. 3 pump rotations times 4 cyl = 12, so if the gear circumference was as such to do 1 pump rotation (3 pump cycles) per injection cycle (12 pumps per engine/crank rotation for example) it would be timed at the top of the cycle at the same time, EVERY single time for each cylinder. It is doubtful they would put a timing mark on the pump sprocket and say it needed to be lined up if it didn't matter so I think MrMopar is right.

But there's two ignitions per crank revolution. That would require two pump revolutions per one crank revolution, or the pump running at twice the crank speed. Is there any other ratio that would put one pump piston at tdc for each firing? Could it be arranged so possibly two pump pistons pulses per ignition??

Could they have put the mark on the sprocket for a 6 cylinder or possibly a 3 cylinder? As I recall the tdi in the VW Lupo is three cylinders.

tonycrd · **Posted:** Thu Jan 13, 2011 6:26 pm

IMO in a common rail system it doesn't matter. Meaning the pump stroke of the HD pump has little to do with combustion at x degrees in x cylinder. (in the good 'ol days when we had big inline pumps or rotating pumps...yes, it did matter)

The timing of the pump must have something to do with the pressure wave, when an injector opens pressure in the rail would drop drasticaly (there is little fuel within the rail) so if there is (-are) no pump stroke(-s) at that time it may cause strange effects. Injectors open before piston reaches TDC....GDE should know more about this....hope they chime in.

Nice thread this is, really interested in why and whatfor.

Joe Romas · **Posted:** Thu Jan 13, 2011 7:28 pm

A quick look at the FSM shows the pump sprocket is smaller then the cam shaft sprockets but not 1/2 the size that the crank sprocket would be. So the pump is not 1:1 with the crank and turns slower. Dividing 120 degrees (degreees between pump pulses) by 180 degrees (degrees of crank shaft piston firings) shows if the pump is turning at 3/4th the crank speed (75%) that would put a pump piston pulse at every engine piston firing :BANANA:

So this is how you can have a pump pulse for every cylinder firing :SOMBRERO:

So if me and my CRD are both around in about 8 more years and I do the work, I'll be 75 then, the mark on the pulley will be aligned :-)r

gmctd · **Posted:** Fri Jan 14, 2011 12:46 am

Sorry, guys, but there are several misconceptions here - to wit:

The fuel rail, supply pipe, and injector pipes hold about a pint of fuel - each injection event pushes several CC's of fuel into the cylinder - that's cubic centimeters - nowhere near the compounded quantity available at the injector inlet - which means that the pressurized fuel rail does not suffer any catastrophic loss or pressure drop at any injection event - each of the three pistons in the CP3 supplys more than enuff fuel for all four injection events, together - this is the same CP3 pump used on the Cummins 5.9L and the Dmax 6.6L, just a little different plumbing and internal regulation for the much smaller 2.8L CRD engine - just think, they have 3 (360cuin I6) or 4 (400cuin V8) injection events per crank rotation, into much larger cylinders, requiring much greater quantity of fuel per event - their CP3's run 180psig internal pressure, the 171cuin CRD CP3 runs 80psig internal pressure - those are the pressures out of the internal lift pump, regulated by their respective COV (see CP3 post for further) viewtopic.php?f=5&t=25047

The pilot injection system employed in the Common Rail systems smooths out the combustion event, keeps it from being so violent, like in the early mechanical injection systems - also helps smooth out the loading on the fuel rail and supply system - instead of having one giant spasm, a few small shivers leads up to the main event, then a few small shivers afterward, then on to the next event - (sorry 'bout that - guess I need to go turn on the furnace)

The CP3 is driven at 1:1 ratio to the crankshaft, and is not timed to the crankshaft - the mark on the drive gear is aligned with a mark on the inner timing cover such that, when the crank is at TDC (where any good service tech would position it prior to performing such procedure), 3 of the six holes in the gear align with the three IP mounting bolts - this allows the installation of a tool that holds and locks the gear in-place while maintaining operating tension on the timing belt - the IP can then be replaced without moving the timing belt, or requiring removal of the timing belt, with that ensuing fracas over camshaft timing - removal is simple: align the holes, unbolt the three fasteners, install the tool, remove the sprocket nut, pull the IP - installation is reverse of that procedure

Nowhere is it mentioned that the IP shaft must be rotated to any specific degree of alignment with the sprocket prior to installation - there is no keyway, no indexing flat, no nothing, just a tapered and ground shaft, mating with a tapered and ground bore - further, with no indexing mark on the shaft or\and sprocket, and no see-thru sight-glass on the IP, how would the shaft be indexed such that any particular plunger\piston would be in position to be correctly timed?

Maybe in an R&D engineering clean-room environment, but not in a service bay.............

gmctd · **Posted:** Fri Jan 14, 2011 10:42 pm

Post script:

CP3 has three pumping pulses per 360deg revolution, one each 120deg - CP3 rotates once per each crank revolution - 4cyl fires twice per 360deg revolution, first cyl at 0deg, second cyl at 180deg, or once each 180deg - CP3 would give one pulse at 0g, engine fires at 0deg - CP3 gives second pulse 120deg later - engine fires 60deg later at 180deg - CP3 gives third pulse 60deg later at 240deg - engine fires third cyl 60deg later at 0deg, CP3 pulse occurs at 0deg, or 120deg from preceding pulse - etc

---------------------------------- 00

--------------------------- 240 ------- 120

--------------------------------- 180

kapalczynski · **Posted:** Sat Jan 15, 2011 4:21 am

gmctd wrote:

Post script:

CP3 has three pumping pulses per 360deg revolution, one each 120deg - CP3 rotates once per each crank revolution - 4cyl fires twice per 360deg revolution, first cyl at 0deg, second cyl at 180deg, or once each 180deg - CP3 would give one pulse at 0g, engine fires at 0deg - CP3 gives second pulse 120deg later - engine fires 60deg later at 180deg - CP3 gives third pulse 60deg later at 240deg - engine fires third cyl 60deg later at 0deg, CP3 pulse occurs at 0deg, or 120deg from preceding pulse - etc

---------------------------------- 00

--------------------------- 240 ------- 120

--------------------------------- 180

Starting to confuse some people here I think (at least me :dizzy:

)...

gmctd wrote:

..."CP3 rotates once per each crank revolution"...

Can you please explain to us how it is possible for the injector pump to rotate at a 1 to 1 ratio if it has a larger diameter pulley than the crank pulley that is turning it via the timing belt??? Do you have a reference for this information?

I did my timing belt myself and the pump allignment mark was exactly off by 1/3 rotation and it seemed likely to me that any of the 3 cycles of the pump can line up with the crank in the same position since the timing belt w/ the crank at the same position was originally installed with the injector pump lined up to the timing mark it has. Based on this info Joe sounds like he is onto something here with the 3/4 75% thing though I think he was a little confusing in his explanation since he mentioned cam sprockets, not crank sprocket:

Joe Romas wrote:

A quick look at the FSM shows the pump sprocket is smaller then the cam shaft sprockets but not 1/2 the size that the crank sprocket would be. So the pump is not 1:1 with the crank and turns slower. Dividing 120 degrees (degreees between pump pulses) by 180 degrees (degrees of crank shaft piston firings) shows if the pump is turning at 3/4th the crank speed (75%) that would put a pump piston pulse at every engine piston firing :BANANA:

So this is how you can have a pump pulse for every cylinder firing :SOMBRERO:

So if me and my CRD are both around in about 8 more years and I do the work, I'll be 75 then, the mark on the pulley will be aligned :-)r

The crank is the smallest pulley, the injector pump is med sized and the cam sprockets are probably 2x the crank pulley's circumference. This would allow the cams to rotate at 1/2 the speed of the crank and the injector pump to possibly rotate at 75% of the speed of the crank. Does that sound right?

Here is a photo of our timing belt setup. You can plainly see the cogged pulley on the crank is smaller than the cogged pulley on the injector pump so this is not possible for them to rotate at the same speed unless the injector pump is geared inside to match the difference in cog sizes.

Please explain more if I am way off base here. gmctd, Is the injector pump geared internally causing it not to be timed with the injection cycles or something?

The injector pump is the cog on the right side in this photo:

- Mark

**EDIT**

If you zoom way in on the photo of the timing setup you can actually count teeth which seems to confirm what I am saying. There are 48 teeth on each cam sprocket (run at 1/2 rotation of the crank rotation), 36 teeth on the injector pump sprocket (run at 3/4 rotation of the crank rotation), and I believe theres 24 teeth on the crank sprocket (hard to tell by the photo, but I counted roughly 6 teeth on 1/4 of the crank sprocket = 24 teeth on the crank). This would put the injector pump cycle at the same position each time the injection happens.

- Mark

kapalczynski · **Posted:** Sat Jan 15, 2011 7:08 am

gmctd wrote:

Sorry, guys, but there are several misconceptions here - to wit:

The CP3 is driven at 1:1 ratio to the crankshaft, and is not timed to the crankshaft - the mark on the drive gear is aligned with a mark on the inner timing cover such that, when the crank is at TDC (where any good service tech would position it prior to performing such procedure), 3 of the six holes in the gear align with the three IP mounting bolts - this allows the installation of a tool that holds and locks the gear in-place while maintaining operating tension on the timing belt - the IP can then be replaced without moving the timing belt, or requiring removal of the timing belt, with that ensuing fracas over camshaft timing - removal is simple: align the holes, unbolt the three fasteners, install the tool, remove the sprocket nut, pull the IP - installation is reverse of that procedure

Nowhere is it mentioned that the IP shaft must be rotated to any specific degree of alignment with the sprocket prior to installation - there is no keyway, no indexing flat, no nothing, just a tapered and ground shaft, mating with a tapered and ground bore - further, with no indexing mark on the shaft or\and sprocket, and no see-thru sight-glass on the IP, how would the shaft be indexed such that any particular plunger\piston would be in position to be correctly timed?

Maybe in an R&D engineering clean-room environment, but not in a service bay.............

Ok, confused again here reading that ^^^ :dizzy:

...pictures would be nice. ha ha On removal you state: align the holes, unbolt the three fasteners, install the tool, remove the sprocket nut, pull the IP

ok, align the holes (done for you if engine is at TDC), unbolt the 3 fasteners (are these the bolts going to the IP - if so, what is holding the pump/sprocket right now before the tool is installed?), install tool, remove the sprocket nut (is this attached to a bearing assembly seperate from IP or attached to IP assembly?), pull the IP(how, if the tool to hold the sprocket is bolted to this? Or is it bolted to somewhere else?)

It definately appears to be timed, at least it seems certain unless it is internally geared, etc based on the difference in circumference of the crank and IP sprockets.

One thing that seems plain to me is that there is 2 actual pump cycles of the 3 cycle per revolution pump (based on 24 teeth on the crank per revolution and 24 of the 36 teeth of the injection pump going by) that occur per engine crankshaft rotation (so the injection pump crank rotates 2/3 of a rotation for every engine crank shaft rotation).

As for your saying it is not keyed during assembly (or at least pressed on in a specific position), that confuses me...If that is true, and the sprocket is not lined up specifically on the pump, then the fact that it is timed doesn't matter(like you said I guess... :banghead:

). I would assume the pump would have to be in a specific position and the sprocket lined up w/ something on the pump if disassembled/reassembled if the timing of the pump piston needed to be in line with an injection cycle - obvious.

I think it is quite possible it is necessary for it to be timed for proper fuel flow based on the fuel pressures needed (20,000+PSI sustained through the injection cycle), but based on the assembly procedures of the pump you gave (again, do you have a reference for this?) it seems it may not need to be specifically timed except for bolt removal on the pump??? In which case it is obvious the 2/3 rotation fo the pump sprocket w/ the 1 rotation fo the crank still lines up.

So, any references or pics to help me understand all this? :dizzy:

- Mark

P.S. I should probably just change my signature to this:

:dizzy:

Joe Romas · **Posted:** Sat Jan 15, 2011 8:57 am

Mark.

Thanks for explaining what I was trying to say. Sometimes I have trouble putting my thoughts into words

I didn't mention the crank sprocket because I couldn't find a picture of it in the FSM. Just one showing the cam and pump sprockets.
And as you stated the cams turn 1/2 the crank speed so crank sprocket has to be 1/2 the size as the camshaft sprockets. The cam and pump sprockets are clearly shown in the fsm and the pump sprocket is clearly larger then 1/2 the the cam sprockets that it would have to be to get a 1 to 1 ratio with the crank.

Did I just confuse it again :dizzy:

A picture is indeed worth a thousand words and it clearly shows the ratio between the crank and pump are not 1 to 1 :BANANA:

When you replaced your belt did you try turning the crank untill the mark was dead on?
I suspect it would eventually line up. Further if my thinking is correct this arrangment would not have the same pump piston being the final push as a injector fires spreading the load equally between all three pistons.

Joe

kapalczynski · **Posted:** Sat Jan 15, 2011 9:11 am

Yep, picture is worth a thousand words...lol

I think it's probably safe to say it's timed w/ the injections, but we have conflicting information as to if it matters or not other than a part installation simplicity.

Silly CRD motor designers...there's gotta be more of a purpose than just bolt access right? :ROTFL:

gmctd · **Posted:** Sat Jan 15, 2011 11:48 am

No, and my bad - I stand corrected, and I appreciate you guys making the effort to illustrate the actuality (that's right - gang up on the old dude!) - all the tech literature I have been able to scrounge up indicates the pump is driven at 1:1 ratio to the crank - even the (dis)service manual is very (un)clear on this point - obviously wrong, by the excellent pics - and again, also just as obviously, I have not been into the 2.8L timing cover - I would, however, suspect that the CP3 is under-driven due to the power required to drive the pump - same requirement on the Cummins and Duramax, but they have more power to share

The IP gear is timed to the cover for service alignment - the shaft and gear are not keyed or indexed, therefore not possible to index without disassembling the IP - again, the tech lit does not go into a procedure for this in any slight detail

Now, how many crank revolutions would it take to realign the pump gear index to the cover index at TDC, from the initial alignment?

Also, appears the IP gear has only three holes, rather than the literature-indicated six - thus, the indexing mark is even more important to R&R'ing the IP

Also also, to achieve a 1:1 ratio, it can be seen that the crank gear could not be any larger or the cam gears would need be inordinately larger, and the IP gear could not be any smaller due to the limitations of the toothed rubber timing belt - pics truly are worth 1k words, eh...................

dkenny · **Posted:** Sat Jan 15, 2011 12:45 pm

um..
actually the IP pulley has 6 holes and is keyed. Atleast the one I'm sitting looking from an '06
what's missing the timing mark on the cover to key the pump too..I have been inside and replaced the CP3. I couldn't find any mark that made sense..yes I looked. just I looked for cam gear marks

I still don't the timing of the pump relative to the crank makes that much difference. it might make some but its a small amount.

from what I have read about the timing of the CP3 on the Cummins isn't a power issue but a noise issue. this make sense.

-dkenny

gmctd · **Posted:** Sat Jan 15, 2011 3:33 pm

Ok, that stirs a memory :dizzy:

- while I do have at least one Cummins CP3 and two KJ CP3A pumps here somewhere, currently unknown, last I saw them was late '08 - early '09, when I was composing the CP3 post - however, I have seen a CP2 with keyed shaft, but have not the foggiest recc that the CP3's do - if so, then all this is moot and simple compounded error :dead:

- however #2, the point is to get the most correct info on the board for reliable reference, so, if someone has pics, let 'er rip - as you may remember, I am one of the most voluble when someone posts misinformation, so it behooves me to correct and update my posts :grim:

Again, the input is appreciated...............

Joe Romas · **Posted:** Sat Jan 15, 2011 5:13 pm

Just remember. To error is human but to really mess up requires a computer :-)r

And for those not aware of it, VW also does not key the sprocket to the camshaft on their diesel engines :idea:

I can only guess it's to get the cam shaft more accuratly timed :roll:

kapalczynski · **Posted:** Sat Jan 15, 2011 6:48 pm

I found this related specifically to the 2.8L CRD:

Quote:

FUEL INJECTION PUMP
DESCRIPTION
A radial, 3 piston pump with a gear type fuel pump
attached to the back, is used as the high pressure
pump for fuel pressure generation (Refer to 14 - FUEL
SYSTEM - WARNING).
The pump is driven by the timing belt. Pressure is
generated independently of the injection process. The
pump is lubricated with diesel fuel and is not responsible
for fuel injection timing.
OPERATION
Cascade Overflow Valve
Instead of using an electric supply pump, this fuel system uses a gear supply pump located inside the rear of the
high pressure pump. The pump is driven by an eccentric on the end of the high pressure pump shaft. The gear
pump draws fuel from the fuel tank through the fuel filter.
The pressurized outlet side of the gear pump provides pressurized fuel to a branched circuit internal to the high
pressure pump flange, which supples both the fuel quantity solenoid and the cascade overflow valve. Because the
gear pump increases fuel flow and pressure as the engine rpm increases, the pressure is regulated by the cascade
overflow valve. The cascade overflow valve and gear supply pump are not serviced independently of the high pressure
pump.
The cascade overflow valve has two functions:
² Regulation of lubrication fuel to the internal moving parts of the high pressure pump
² Regulation of the fuel pressure being supplied to the fuel quantity solenoid
The cascade valve has a machined center piece that has three drillings. One for overflow, one for lubrication and
one for supply. The valve works in three stages based on the pressure entering the inlet of the valve.
Stage 1
When the fuel pressure entering the tip of the cascade valve is between 0 and 3 bar (44 psi), the spring force is not
overcome and fuel only flows through the center drilling. This drilling always allows fuel flow through to the pump
center ring and lubricates the pump bushings and internal moving parts. This circuit also allows air to bleed during
initial cranking and returns the air to the fuel tank. The cascade valve is only in stage one during cranking.
Stage 2
When the fuel entering the cascade valve exceeds 3 bar (44 psi), but is less than 5 bar (73 psi), the center piece
of the valve moves against the spring force aligning another passage for lubrication purposes. Stage 2 can be
reached during cranking and initial start up.
14 - 54 FUEL DELIVERY - 2.8L DIESEL KJ
Stage 3
When fuel pressure exceeds 5 bar (73 psi), the center of the valve aligns with the overflow passage. This stage
relieves the pressure into an overflow circuit that sends the fuel back to the inlet side of the gear pump which limits
maximum fuel pressure to 5 bar (73 psi). Lubrication fuel also continues to flow though the other ports during this
stage. Excess is sent back to the fuel tank through the return circuit.
High Pressure Pumping Plungers
The fuel quantity solenoid supples three high pressure pumping chambers. The pumping chambers have one way
inlet valves that allow fuel to flow into the chambers. The valves then close during compression of the fuel and
cause the high pressure fuel to overcome a ball and angled seat outlet valve.
All three pumping chambers are tied together in one circuit internal to the pump and provide high pressure fuel up
to 1600 bar (23,000 psi) through a steel line, to the fuel rail.
The pump is driven at 1:1 engine speed and is not responsible for injection timing. The pump is only responsible for
providing high pressure fuel while the ECM controls the injection timing.
REMOVAL
WARNING: High - pressure lines deliver diesel fuel under extreme pressure from the injection pump to the
fuel injectors. This may be as high as 1600 bar (23,200 psi.). Use extreme caution when inspecting for high
- pressure fuel leaks. Fuel under this amount of pressure can penetrate skin causing personal injury or
death. Inspect for high - pressure fuel leaks with a sheet of cardboard. Wear safety goggles and adequate
protective clothing when servicing fuel system.
1. Disconnect negative battery cable.
2. Remove engine cover and bracket (Refer to 9 -
ENGINE - REMOVAL).
3. Evacuate A/C system (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - STANDARD
PROCEDURE).
4. Remove cooling fan and fan shroud.
5. Remove accessory drive belt (Refer to 7 - COOLING/
ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
6. Remove fan support assembly (Refer to 7 - COOLING/
ENGINE/RADIATOR FAN - REMOVAL).
7. Bring piston #1 to TDC, turn crankshaft until notch
on the crankshaft hub is at the 12 o’clock position.
8. Looking at the engine from the belt side, rotate the
crankshaft 90° clockwise.
9. Remove the intake and exhaust camshaft plugs
from the camshaft cover, to introduce the camshaft
timing pins VM.1052 Intake, and VM.1053 Exhaust
(if the engine is timed correctly, the pins can be
installed).
10. Remove timing belt outer cover (Refer to 9 - ENGINE/VALVE TIMING/TIMING BELT / CHAIN COVER(S) -
REMOVAL).
11. Using special tool VM.1055, remove high pressure injection pump sprocket retaining nut.
KJ FUEL DELIVERY - 2.8L DIESEL 14 - 55
NOTE: The use of special tool VM.1067 will allow
you to remove the high pressure injection pump
without removing the timing belt from the engine.
This will allow you to remove and install the high
pressure injection pump without altering engine
timing.
12. Install feet from VM.1067 in injection pump
sprocket as shown.
13. Install inner flange of special tool VM.1067 on
injection pump sprocket as shown. Secure flange
to feet in injection pump sprocket with allen bolts
supplied with tool.
14 - 56 FUEL DELIVERY - 2.8L DIESEL KJ
14. Screw the high pressure injection pump sprocket
holding plate assembly into flange of VM.1067
Using left hand threaded bolt supplied, secure
holding plate assembly to timing belt inner cover.
15. Remove the EGR airflow control valve from the
intake manifold (Refer to 25 - EMISSIONS CONTROL/
EXHAUST GAS RECIRCULATION/VALVE -
REMOVAL).
16. Remove high pressure injection pump to fuel rail
high pressure line.
17. Disconnect high pressure injection pump quantity
control valve electrical connector.
18. Disconnect fuel supply and return lines at high
pressure injection pump.
19. Remove alternator to intake manifold bracket.
CAUTION: Care must be taken not to bend the
brake vacuum tube when removing high pressure
pump.
20. Remove high pressure injection pump retaining
nuts and remove pump.

It seems pretty specific about the 1:1 and it not being timed. We can't blame you gm for the incorrect info you have to pull your data from. :ROTFL:

So what have we learned? Even the most trusted source that the mechanics use is wrong! LOLOL So how will we ever know what is actually correct?!? This is a bit concearning, or at least it would be if I still had my CRD. :goink:

Just kidding, I feel for you guys. And want to know the inter workings of the CRD even though I currently don't own mine anymore, its interesting stuff and I may end up w/ annother one someday

It does help to explain how the Jeep mechanics have issues. When their info they have for a source to trouble shoot things is flawed it does explain things a little but...though I know for a fact the books cannot be blamed for all the dealer service mistakes.

Again, this only solidify's the fact that I won't take my vehicle to anyone if I can help it. I'd rather see for myself and KNOW what is going on before I seek further help if it is needed.

dkenny wrote:

um..
actually the IP pulley has 6 holes and is keyed. Atleast the one I'm sitting looking from an '06
what's missing the timing mark on the cover to key the pump too..I have been inside and replaced the CP3. I couldn't find any mark that made sense..yes I looked. just I looked for cam gear marks

I still don't the timing of the pump relative to the crank makes that much difference. it might make some but its a small amount.

from what I have read about the timing of the CP3 on the Cummins isn't a power issue but a noise issue. this make sense.

-dkenny

As mentioned, the cam gears do not need to be timed, the timing marks on the cam gears are not needed and there is no mark they need to line up with. However, the Injection pump is timed, though the timing may not matter other than for the service access. There is a mark, though it is hard to see being right below a bolt on the rear timing cover.

Here's a photo of the injection pump cam gear and timing mark. Photo is courtesy of Green Diesel Engineering (thanks Keith!):

ANYWAY, anyone have a photo of the injection pump itself out of the vehicle??? I wanna see proof of it being keyed or not. lol

dkenny, if you are saying it is keyed (I think you were, though I think you were missing an "at" so it was a confusing statement), I believe you, if it is indeed keyed, and it has a timing mark to match on the housing behind the sprocket (which it does at least on my '05 I did my belt on), I think it best to put it in the correct position wether or not it is necessary. At least that's what I would do. It may or may not hurt performance or economy or be noisier, but you can't go wrong by putting it in its original engineered position.

P.S. I still want a photo of the keyed injection pump if someone has one? I'm curious what our specific pump looks like.

- Mark

kapalczynski · **Posted:** Sat Jan 15, 2011 7:17 pm

gmctd wrote:

No, and my bad - I stand corrected, and I appreciate you guys making the effort to illustrate the actuality (that's right - gang up on the old dude!) - all the tech literature I have been able to scrounge up indicates the pump is driven at 1:1 ratio to the crank - even the (dis)service manual is very (un)clear on this point - obviously wrong, by the excellent pics - and again, also just as obviously, I have not been into the 2.8L timing cover - I would, however, suspect that the CP3 is under-driven due to the power required to drive the pump - same requirement on the Cummins and Duramax, but they have more power to share

Now, how many crank revolutions would it take to realign the pump gear index to the cover index at TDC, from the initial alignment?

LOL not ganging up on the old guy - we like the old guy, he has wisdom we need to aquire before we get old so when we are there we can teach the youngin's ourselves when the time comes. lol Just getting to the bottom of all this nonsense...not your nonsense, but the incorrect service manual nonsense! LOL

If crank is 24 teeth and the Injection pump is 36 teeth, it would take 3 crankshaft rotations to get the Injection pump in the correct spot and alligned w/ the mark. Now if you wanted that at TDC with #1 piston it may take several tries to get everything lined up. - Trust me my math is right on this one, I drew a picture...its just too ugly to upload and share with everyone...lol

Thankfully, it is not necessary if you leave the pump in its original position or time it to the mark again it is all the same and will keep one of its 3 cycles where it is supposed to be (if it is indeed supposed to be anywhere at all...lol) as long at it is put back to its timed mark even if it was 1/3 or 2/3 rotations from this it will still be properly timed.

- Mark

gmctd · **Posted:** Sat Jan 15, 2011 8:40 pm

You may also notice that those six holes are not equi-distant, as should be for 0 - 60 -120 - 180 - 240 - 300 - (360), but are rather bunched in pairs across 0 - 120 - 240 - a conundrum of epic proportion, eh - or, could it be to allow the gear to be offset a couple notches, for some esoteric reason?

p.s. - keep those pics coming, folks - we have been needing this for a long while, in light of the many errors in the FSM, also the parts manual

kapalczynski · **Posted:** Sun Jan 16, 2011 2:23 am

gmctd wrote:

You may also notice that those six holes are not equi-distant, as should be for 0 - 60 -120 - 180 - 240 - 300 - (360), but are rather bunched in pairs across 0 - 120 - 240 - a conundrum of epic proportion, eh - or, could it be to allow the gear to be offset a couple notches, for some esoteric reason?

p.s. - keep those pics coming, folks - we have been needing this for a long while, in light of the many errors in the FSM, also the parts manual

Not really a conundrum, if the pump has 3 bolts holding it in place and they are not equally spaced it may be necessary.

It's quite possible the pump bolts are not at exact degrees appart so 6 holes are necessary for 3 of the holes on the pulley to line up with the the non equidistant pump bolts at any given position when at TDC. :BANANA:

Example:

Say the pulley's holes are spaced like a clock... paired at the 12&1, 4&5, 8&9 o'clock positions. Now say our 3 pump bolts are at 12, 5, and 9 o'clock positions and are not equidistant from each other. The 6 paired holes would let it line up no matter what position, as long as it is at one of the 3 timed positions that it can be at TDC since it will very depending on the rotations of the crank, etc since the crank is 24 teeth and the IP is a 36 tooth sprocket.

Annother possibility is the pulley is used in multiple applications and has holes for both(3 that line up for service on 1 application, 3 line up on a different application??? - I wouldn't put it past the engineers of this madness of an engine system- lol

- Mark

dkenny · **Posted:** Sun Jan 16, 2011 9:43 am

that's where they hid the timing mark no wonder I didn't see it.

yes the shaft is keyed..sorry about my terrible typing and grammer

photo of the gear

I can also take one of the shaft the gear mounts too if someone wants that.

all this makes me wonder if I got the timing right or not..This will have to wait until I have to remove the cover again.

Thanks for the info

-dkenny

CRD Injector pump update. Gonna have to sell the CRD :(

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