Timing Chain SOS - please help!! - Page 4 - PeachParts Mercedes-Benz Forum

Ace Taxi · #46 02-22-2009, 02:38 PM

Here's the data:

With tang in the middle of the port, crank reads +22*
Cam mark seems to be near 180* +/-20*

Compression test either later or tomorrow

Again, I am grateful to all for your input.

sixto · #47 02-22-2009, 02:50 PM

+22* is 22* ATDC or BTDC? Spec is 15* ATDC so 22* is not too far off. Might not be within the adjustment range of the IP. Might have to move the IP timer a spline or two to get it in range.

What do you mean cam timing is 180*? Cam timing when the IP lug is showing is irrelevant. Give the crank another spin to align the cam notch with the cam tower then read the crank pulley again.

Sixto
87 300D

Ace Taxi · #48 02-22-2009, 03:05 PM

To clarify:

By +22* I meant 22* ATDC, that is, the hash marks to the RIGHT of 0* as you look down on the crank pulley.

JonL · #49 02-22-2009, 03:12 PM

Looking down at the pulley, the marks reading left to right start at ATDC. In other words:

ATDC 30 20 10 0T 10 20 30 40 BTDC

I don't recall exactly the marks, and the "ATDC," and "BTDC" aren't actually marked.

Here's what you want it to look like when the pump is timed properly:

20 * 10 0T 10 20 30

0T is TDC. the * is where you want the pointer on the front cover. The number one cam lobes should be pointing more or less away from the valves, in other words, valves closed.

Ace Taxi · #50 02-22-2009, 03:28 PM

Then if I have the nomenclature correct, the crank pulley reads 22* BTDC with the tang visible.

30 20 10 0 10 20* 30

I will double check this and try to snap a pic to eliminate any doubt.

Ace Taxi · #51 02-22-2009, 03:31 PM

also - the pointer has a flat face on the passenger side, angled face on the driver's side. I am reading the mark that is aligned with the flat face of the pointer. This is the correct reading as I understand it - but I add it here to eliminate all doubt.

Brian Carlton · #52 02-22-2009, 03:53 PM

Quote:

Originally Posted by Ace Taxi

also - the pointer has a flat face on the passenger side, angled face on the driver's side. I am reading the mark that is aligned with the flat face of the pointer. This is the correct reading as I understand it - but I add it here to eliminate all doubt.

Please do two things:

1) Take a good photo of the pointer when the tang is in the middle of the window on the IP port. Please post it.

2) Look at the camshaft.........take the valve cover off if necessary........are the lobes of #1 generally pointing up and away from the valves (valves closed)........or are the lobes pointing downward and both valves are open?

Ace Taxi · #53 02-22-2009, 04:38 PM

Here are the pics

DIESELVOLVO · #54 02-22-2009, 05:21 PM

O.K.

If your pump is at start of delivery and everything on your engine looks like it is in the photos then your problem is that you do not understand that when an engine is about to fire on the compression stroke then both valves of that cylinder need to be closed. If you look at the camshaft LOBES, not rockers but lobes meaning the pointy ends of the egg shaped portions of the cam shaft, both of them on number one cyl. need to be pointing up at 10 and 2 o'clock (like bunny ears) when the crank is at 20ish BTDC or whatever the spec is for your engine. Then when fuel is injected there will actually be some compression in the cylinder in order to fire that fuel and keep that crankshaft rotating.

Brian Carlton · #55 02-22-2009, 06:00 PM

DieselVolvo is correct.

The camshaft is out by 180 degrees and needs to be returned to the original position when the vehicle was running.

The timing of the IP is 22°BTDC, which is 37° early. The engine will run like crap at that timing setting. The IP needs to be removed and reinstalled.

sixto · #56 02-22-2009, 06:05 PM

What DIESELVOLVO said. What you should do, according to me, is align the notch in the cam sprocket flange with the mark in the front most cam tower then look at the crank pulley and read the position. The passenger side edge should be at or within a couple of degrees of 0T. If not, that's a problem. Then, remove the IP plug and watch for the lug to center in the port as you nudge the crank to 15* ATDC. If not, that's a problem.

Sixto
87 300D

JonL · #57 02-22-2009, 06:08 PM

Quote:

Originally Posted by Brian Carlton

DieselVolvo is correct.

The camshaft is out by 180 degrees and needs to be returned to the original position when the vehicle was running.

The timing of the IP is 22°ATDC, which is 7° late. The engine will run like crap at that timing setting. The IP needs to rotate toward the engine.........if there is sufficient travel. Otherwise, as Sixto mentioned, the pump must be removed and reinstalled with the housing and spline rotated one tooth away from the engine.

According to the picture, the cam is out 180 degrees and the IP timing is at 22 BTDC, not ATDC. The pump will need to be removed and retimed.

Ace Taxi · #58 02-22-2009, 06:11 PM

Thank you for the feedback, you guys have been a huge help.

I have a couple of questions, but first, to clarify:

30 20 10 0T 10 20 * 30

The asterisk is where the pointer is - is this ATDC or BTDC?

Brian Carlton · #59 02-22-2009, 06:12 PM

Quote:

Originally Posted by JonL

According to the picture, the cam is out 180 degrees and the IP timing is at 22 BTDC, not ATDC. The pump will need to be removed and retimed.

You're absolutely right..........

I must have been hoping for ATDC.

That's a bad sign. 22°BTDC is 37° off the spec.

Brian Carlton · #60 02-22-2009, 06:15 PM

Quote:

Originally Posted by Ace Taxi

Thank you for the feedback, you guys have been a huge help.

I have a couple of questions, but first, to clarify:

30 20 10 0T 10 20 * 30

The asterisk is where the pointer is - is this ATDC or BTDC?

My original mistake.

The position of the asterisk is BTDC.