I'm planning to dig into the beast tomorrow, including installing the new ProVent 200. If you were going to do it again, would you change anything? Should I mount the ProVent a little lower than the CCV puck so no filthy oil can return to the engine? It would mean checking the oil more often and adding a quart once in a while.
Dean.

Starting to put the beast back together and noticed an issue with the camshafts sprockets. One has been slightly off since the last installation so I'm considering making some alignment pins to ensure they go on right. See the pictures here.

With the crankshaft at 3 o'clock, I like to install the sprockets so the witness marks have some meaning, as in this picture. They are almost facing each other at 3 o'clock and 9 o'clock - but the spokes are aligned perfectly. This configuration makes the timing belt nice and tight across the tops of both sprockets.


Also with the crank at 3 o'clock, the 4.8mm camshafts key ways are exactly facing each other at 3 o'clock and 9 o'clock. However, with the sprockets installed, you cannot see the key ways anymore so you never truly know if you got them right.


Since I did install the camshaft sprockets this way last time, I noticed markings (dark areas) on the mating surfaces between the sprockets and the camshafts. It indicated the intake camshaft sprocket was slightly off, maybe 1-1/2 or 2 degrees. The engine ran fine but I know these are interference engines. Luckily, there as no valve/piston contact this time but it does worry me. Notice that the spoke across from the key way marking has some numbers stamped in it. Both gears are the same.



Much better to put the cam timing pins in & the one in the flywheel.
Then install the belt & tension it. Then tighten the bolts on the cams. That way you have the flexibility to account for any stretch in the belt or ware on the pullies.
If you key the pullies to the cams, you loose that adjustment. Once all done up & pins out of the cams & flywheel, turn the motor over by hand for 3 or 4 turns & recheck by putting the pins back in.

I've come up with an sure-fire installation trick that I plan to implement with this installation. I'll drill to tiny holes 1.5mm (1/16") in each sprocket (as shown) and insert two alignment pins just for installation. The key way is 4.8mm wide, so I'll drill holes that make the pins span ~4.7mm. This will guarantee the sprockets will go on correctly. I doubt two tiny holes will impact the structure of the sprockets. I'll remove the pins afterward to prevent them from falling out.


I think it would be wise to let the machinist drill the holes. I can probably get them right on my drill press, but I think the machinist has a better chance. The machinist may talk me into drilling a single 4.8mm (3/16") hole and install a single 4.8mm pin in each sprocket and leaving it there. The bolt will cover a portion of the 4.8mm diameter pin.

Dean.

It's still odd to me that the fuel pump sprocket only aligns at the witness mark every third 4-stroke rotation.
Dean.

Posted by GDE back in 2011:
Based on the number teeth on the pulleys (24 for crank, 48 for cam and 36 for IP) the pump timing make will line of with the crank every 3 revolutions. However, to get the entire system in the correct timing position it will occur every 6 revolutions (where crank is 90 degrees after TDC, cam pins line up and IP is pointed at the timing mark).

A pump with the wrong timing can lead to lower power and higher noise as posted earlier in the discussion. This is due to the internal pressure wave in the rail. If the wave pulse is not timed with an injection event correctly, the pressure at the injector nozzle might be lower than desired when the injector is energized. This may lead to a lower pilot injection quantity or a missed pilot, thus leading to more combustion noise (typical pilot duration is 180-200 micro seconds). The main injection may have a lower actual injected quantity as well due to out of phase pressure wave (main injection pulse width can range from 200-1200 micro seconds depending on load). These pulse widths are for the Liberty CRD, other common rail applications can be different, depending on injector flowrate, solenoid actuation vs. piezo actuation, number of injections (two pilots, main and post), etc.

Had a surprise experience with Limp-In mode. The engine ran fine except there was no power except slightly more than idle speed. Got home and the Code Reader told me the Glow Plugs or Glow Plug Control Module had low voltages.

Did a little digging around and identified the Glow Plug Control Module. The Field Service Manual has this picture backwards. I flipped it horizontally and now it's correct.


We don't need glow plugs in the tropics so I unplugged the Glow Plug Control Module. Jeep runs fine again. Next time I have to dig into the engine compartment, I can strip out the Glow Plug wiring. It makes me feel better when I can simplify this Chrysler beast.

Can the Glow Plug system be deleted from the computer?

Dean.

Hi Dean;
This is the drawing that I have on file (see below); let me know if you think it is incorrect.

Thanks for the response layback40,

If I was interested in fixing the glow plugs, then I'd probably replace the unit. The book says to check each glow plug with a multimeter looking for less than 0.8 ohms in each glow plug. Otherwise, the Glow Plug Control Module would be the problem. Changing glow plugs means removing the intake which is a pain, but not impossible.

Your conclusion of the computer pulsing the glow plugs sounds valid. There is a lot of Pulse Width Modification control throughout these Chrysler'ized Jeeps.

Dean.