Top End Teardown

galatron · **Posted:** Tue Feb 28, 2012 9:12 pm

Well dang it ..... it won't start! Turbo bill and I got everything lined up checked the pins twice. Rotated by hand six or more times. Checked the pins. Cranked no start... pumped the primer bleed air fuel. No codes... won't start... weird.

msilbernagel · **Posted:** Wed Feb 29, 2012 12:15 am

Have you left anything unassembled or disconnected in order to perform the test prior to re-installing 'everything'?

galatron · **Posted:** Wed Feb 29, 2012 10:40 am

Yes, I plugged in all the sensors, and just left them hanging. accessory belt is not on, nor is the front cover. I checked alignment again after attempting to start, everything seems good.
We loosened one of the injector fuel lines and fuel came out.
I am ordering the special pins to set alignmnent to verify that we've set everything correctly. - we used home made pins and the allen key on the flexplate. - I trust that we got it right, I just want to be SURE we got it right.

msilbernagel · **Posted:** Wed Feb 29, 2012 1:42 pm

Alternator connected? I wonder if there are any items the ECM would notice missing or 'irrational' and prevent a start for?

turbobill · **Posted:** Thu Mar 01, 2012 8:56 pm

When I started my engine after top end rebuild, I did not have the alternator connected. Everything else except the MAP sensor was plugged in, turbo hoses on, coolant hoses on, it cranked right up after turning over 6 or 8 times. I have a lift pump with the fuel filter head vent connected to the diesel return line so I could turn on the pump until I could hear the fuel hitting the fuel tank in the return.

Galatron did not have his turbo connected, his EGR ports were open and he did not have his radiator connected. The great mystery was that there were NO codes after Galaton plugged in his sensors.

The fuel filter would pump up hard then soften as the engine was cranked so it seems fuel was flowing. Mystery, Mystery.

ATXKJ · **Posted:** Thu Mar 01, 2012 9:58 pm

basic Jeep stuff - did you check battery voltage?

Having enough voltage to turn on the computer,
is different from having enough current to turn it over.

and the computer is an on/off switch for ignition.

galatron · **Posted:** Thu Mar 01, 2012 11:31 pm

Err.. we were able to turn the engine over at least 10 times for about 5-10 seconds each.

msilbernagel · **Posted:** Fri Mar 02, 2012 2:51 am

So... no sign that it's firing at all?

You need fresh air compressed sufficiently to auto-ignite the diesel and fuel injected at the right time.. so the job is to figure out which part is missing and why. Since diesels use compression to heat the fuel to its autoignition temperature (410F or so), anything that compromises compression is suspect.

Take a peek around the injectors and see if there's any sign that compression is leaking by; fuel, perhaps.

Did you use new lifters also? If not, perhaps they're not at full height..?

Things that might hinder reaching sufficient compression to ignite the fuel:

1. Injectors & their O-rings (new o-rings / copper washers?)
2. Valves - no sign of being bent and therefore slightly open?
3. Lifters & rocker arms (assume you've replaced them - no chance one or more fell off, right?)
4. Rings
5. Failed glow plug(s)

Things that might prevent fresh air from reaching the cylinder:

1. Valves not opening
2. Rockers
3. Lifters
4. Cam
5. Maybe..the FCV (but it's doubtful it would block sufficiently to not at least try to fire.

Things that might prevent the engine from providing fuel:

1. Air in system
2. Leak in the high-pressure lines - even a tiny one - will keep it from reaching sufficient pressure to get the fuel in. Been through this with a Cummins using the same Bosch fuel system.
3. Failed high-pressure fuel rail pressure sensor (connector seated)? You didn't take it off the rail, did you?
4. Connectors not fully seated (injectors, cam position sensor, map, etc) - you probably disconnected them all with the cover, right?
5. Bosch fuel pump metering valve - did you disconnect it?
6. You didn't reconnect the hoses in/out of the fuel filter backwards... surely.. ; ' )

Things that might prevent the ECM from firing:

1. Sensors not connected - esp Cam position or injectors
2. Poor ground
3. Low battery voltage

Things that might affect timing of fuel/valves (etc): cam gears not correctly aligned during install.. I know you're looking into that.

Well - just trying to throw out a list you might use to narrow it down.

Can you do a compression test?

Mark

galatron · **Posted:** Fri Mar 02, 2012 2:34 pm

msilbernagel wrote:

So... no sign that it's firing at all?

No sign of firing - at all

Take a peek around the injectors and see if there's any sign that compression is leaking by; fuel, perhaps.

No Leaking fuel except where we loosned fitting to see if there's fuel coming out.

Did you use new lifters also? If not, perhaps they're not at full height..?

I rebuilt all my lifters and they are all at the same height

Things that might hinder reaching sufficient compression to ignite the fuel:

1. Injectors & their O-rings (new o-rings / copper washers?)
New orings and copper washers
2. Valves - no sign of being bent and therefore slightly open?
No sign of bent valves, I checked them all with a straight edge
3. Lifters & rocker arms (assume you've replaced them - no chance one or more fell off, right?)
Replaced all rocker arms, rebuilt the lifters
4. Rings
did not inspect - it was running before
5. Failed glow plug(s)
replaced one glow plug that tested bad, all pass now and don't throw coded.

Things that might prevent fresh air from reaching the cylinder:

1. Valves not opening
I hand turned the cams and you can tell that the cam is loaded and equally loaded.
2. Rockers
same as above
3. Lifters
same as above
4. Cam
Cam is in "alignment" with homemade tools that worked for turbobill.

5. Maybe..the FCV (but it's doubtful it would block sufficiently to not at least try to fire.
FCV has had it's butterfly removed and is plugged in

Things that might prevent the engine from providing fuel:

1. Air in system
Possibly, but we cracked the input to FI #1 and fuel came out.
2. Leak in the high-pressure lines - even a tiny one - will keep it from reaching sufficient pressure to get the fuel in. Been through this with a Cummins using the same Bosch fuel system.
No Apparent leaks observed
3. Failed high-pressure fuel rail pressure sensor (connector seated)? You didn't take it off the rail, did you?
did not remove electronics from the rail
4. Connectors not fully seated (injectors, cam position sensor, map, etc) - you probably disconnected them all with the cover, right?
I did disconnect and I did remove from the cover. however they don't throw codes...
5. Bosch fuel pump metering valve - did you disconnect it?
did not remove
6. You didn't reconnect the hoses in/out of the fuel filter backwards... surely.. ; ' )
uh... nope

Things that might prevent the ECM from firing:

1. Sensors not connected - esp Cam position or injectors
No bad codes, everything passes!
2. Poor ground
?
3. Low battery voltage
I'm on a fresh battery connected to a 10amp charger. we cranked till the battery died.

Things that might affect timing of fuel/valves (etc): cam gears not correctly aligned during install.. I know you're looking into that.
Waiting for the pins to show up at my door.

Well - just trying to throw out a list you might use to narrow it down.
THANK YOU VERY MUCH! It is very helpfull to have a "checklist" of sorts to troubleshoot this thing!

Can you do a compression test?
I don't have the tools to do a compression test, but on hand turn, it's pretty dang good I'd say!

Mark

dieseldawg · **Posted:** Fri Mar 02, 2012 2:42 pm

Just a thought and I was looking back to your initial post, but could not see why you are tearing down the top end.

Is your timing on the crank off by 1-360 degree revolution. Since the cams turn at half the speed of the crank, are you one revolution off on the crank. If it was running before tear down, ignore my comment.

turbobill · **Posted:** Fri Mar 02, 2012 11:04 pm

Well, the crank and cams being out of time could make sense. but how does one know when the crank is in the correct location to time the cams with the cam pins? It makes sense that that is the problem with Galatron's Jeep since he could be on the exhaust stroke when he should be on the compression stroke. What is the danger in rotating the crank one rotation where the cams are out of time with their pins and then resetting the cams?

When I did my Jeep I pinned the cams before I removed the top and the crank was pinned so it could not have been rotated out of time. That's how I discovered my timing belt screw up. When I reinstalled the top, the crank was timed to the cams since all the pins were installed BEFORE the tear down.

Galatron if you would like me to come over and help move the timing, I would be glad to do so.

1. put pins in cam and crank
2. pull timing belt
3. pull the crank pin and rotate one revolution then replace pin
4. reinstall timing belt
5. start engine

geordi · **Posted:** Fri Mar 02, 2012 11:12 pm

Do you think it is safe to try and rotate the crank with the cams pinned and the rockers in place? It seems to me that you might risk impacting the valves, even turning by hand, b/c some of the valves might be open with the cam pinned. I could be wrong about this, but that is just the first thought that comes to mind. I wouldn't want you to eat more rockers after all the wrenching I'm sure you have done.

What about just pinning the crank in the right spot, pulling the belt and manually rotating each CAM, exactly 180* clockwise from where it is? Yes, I know that the pins won't go in, but then you reinstall the belt, flip the crank 360* and check the pins again. If you scribe the existing teeth pointing at each other on the cams, they should match if / when the pins go back in. I'm guessing here, I hope I never need to figure this out. This might be why I got about 40 rockers in my box of parts from the engine replacement.

msilbernagel · **Posted:** Sat Mar 03, 2012 1:22 am

I don't see how this could be a/the problem.

Whether or not the engine is on the intake or exhaust portion of the 4-cycle is a function of where the cams are.

The crank is set at 90ATDC of Cyl #1 - with the PIN. This is in part so that the piston is lowered past the point where the valves can hit them and allows the mechanic to get the cams into place.

In 4-cyl engines cyls 1 and 4 are up at 0-deg, while cyls 2 and 3 are up (TDC) at 180-deg.

If there is only one hole in the flex-plate, then there is only one place the crank can be with the pin installed correctly - 90ATDC on cyl #1.

The cams pins insure that the intake and exhaust are locked for 90ATDC of the intake stroke for cyl #1.

In what scenario can you lock the crank at 90ATDC, set the pins into the cams, and not be precisely where you should be (other than a tooth or two either direction, by accident)?

...unless, there is a different, larger and not-the-correct-hole that the crank alignment pin can go into?

I've looked at the camshafts - there is no other hole for the alignment pins.

Mark

msilbernagel · **Posted:** Sat Mar 03, 2012 1:44 am

geordi wrote:

Do you think it is safe to try and rotate the crank with the cams pinned and the rockers in place? It seems to me that you might risk impacting the valves, even turning by hand, b/c some of the valves might be open with the cam pinned. I could be wrong about this, but that is just the first thought that comes to mind. I wouldn't want you to eat more rockers after all the wrenching I'm sure you have done.

NO! This, from page 9-200 of the [2005] service manual (CAMSHAFT):

"CAUTION: Before removing the cylinder head cover/
intake manifold or timing belt the engine must
rotated to the 90° ATDC, or the 3 O’clock position.
Failure to do so could result in valve and/or piston
damage during reassembly. (Refer to 9 - ENGINE/
VALVE TIMING - STANDARD PROCEDURE)"

geordi wrote:

What about just pinning the crank in the right spot, pulling the belt and manually rotating each CAM, exactly 180* clockwise from where it is? Yes, I know that the pins won't go in, but then you reinstall the belt, flip the crank 360* and check the pins again. If you scribe the existing teeth pointing at each other on the cams, they should match if / when the pins go back in. I'm guessing here, I hope I never need to figure this out. This might be why I got about 40 rockers in my box of parts from the engine replacement.

I believe the way you get two crank rotations for one cam rotation is the gear ratio between the crankshaft (# teeth / dia) and the camshafts teeth/dia. There are twice as many teeth on the cam gears as the crank (someone count them, mine's buttoned up), so a complete crank revolution only turns the cam gears 180-degrees. This results in ONE intake valve opening for every TWO crank rotations, and ONE exhaust valve opening about 180 out of phase with the intake - also for each two crank revolutions.

The PINS, if correctly installed, are supposed to lock the crank and cam at exactly 90-degrees of the 720-degree (4-stroke) combustion cycle.

IF you rotate the cams with the crank NOT AT 90-ATDC and the cams attempt to push open the valves - you will damage something.

Mark

BlackLibertyCRD · **Posted:** Sat Mar 03, 2012 1:54 am

Mark

BlackLibertyCRD · **Posted:** Sat Mar 03, 2012 1:54 am

Mark

BlackLibertyCRD · **Posted:** Sat Mar 03, 2012 1:54 am

Mark

I guess this is what happens when web page get stuck. How do I delete two post?

turbobill · **Posted:** Sat Mar 03, 2012 12:28 pm

I believe Harlan had his came a d crank unpinnes when he disassembled his engine. If he rotated his crank to the "wrong " cycle before he remounted his came he would have his engine timing out of phase. He would be pushing on a compression stroke while his exhausted valves would be opening. This would probably work OK except his fuel pump would also be out of time. I think we need to hear from Sir Sam.

msilbernagel · **Posted:** Sat Mar 03, 2012 6:34 pm

There's an index 'dot' on the crankshaft pully that the service manual instructs you to place at 12 o'clock, and then rotate CW (right when facing the engine) 90 degrees until the dimple/index is at 3 o'clock. I did this and the pin when into the flex place with no adjustments, several times.

When you've taken the belt off for top-end service as we have, and follow the FSM instructions using the Miller Tool pins as instructed, there is no 180 degrees off; that is what the pins are for.

Mark

turbobill · **Posted:** Sat Mar 03, 2012 7:45 pm

I understand, but the engine is a 4 cycle engine so for cylinder 1, one rotation gives you compression then then the next gives you exhaust.(I know you know this I am just trying to be clear about my supposition. Assuming a first-time-ever-time the cams can be timed to the wrong engine cycle by pinning the flywheel on the exhaust stroke instead of the compression stroke. Doing so the engine won't start. I am not a real savvy diesel guy but this makes sense as to why the engine would not start after it was put back together, since it was running before the tear down.

If my assumptions are out of whack please clear things up for me.

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