Hi everybody,

I've read several threads about timing with a drip tube, but I'll have some difficulties to understand the process !!

When you say remove the valve and the spring, where are they located, (at the level of the indication on the attached photo ???)


The others question, on my W124 300TD2.5 i don't have a manual pump to make pressure on diesel circuit, how to do to observe the fuel flow ????


If you know any thread that describe the process for similar configurations as mine, please give me its reference,

thanks a lot..

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I know there are some great ones in these 15....

Diesel Injection:

Drip Timing Threads

.

Hmmmm, thanks

But didn't find pictures
and what about the valve and spring to remove before placing the
drip Tube ??

Remove the hex socket head screw holding the clamp.

Use a special 31-spline? socket to remove the delivery valve cover.

There is a sring under the cover.

You'll probably need a new o-ring for the delivery valve cover.

There is a special tightening procedure for the the delivery valve covers of a 603.961. I suspect there is a similarly special prodecure for your 602.xxx.

HOWEVER, I've heard that the drip method of timing is not the best or even advisable for the 'newer' Diesels. Much better to use an A-B light. It drives techs nuts but DIYers find it acceptable to use the IP locking tool as a guide to setting timing.

Sixto
91 300SE
87 300SDL
83 300SD

Thanks sixto,

Is it necessary to remove the spring and the valve on the buble method,

And for the drip method, according to the attached image, I suppose that the valve cover should be replaced before engaging the drip Tube

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The shop manual I have for my 603 doesn't mention the drip method so I don't know how to advise you.

The shop manual for the 617 says:

- turn engine so it's just before the start of delivery position for cylinder #1

- remove the delivery valve and spring for cylinder #1, refit delivery valve cover and fit drip tube

- loosen the return fitting on the fuel filter, hand pump until fuel is expelled from the drip tube

- set the throttle linkage to full load

- turn crankshaft in direction of normal rotation until you see one drop per second from the drip tube

- adjust the IP if necessary so the point of one drip per second coincides with the start of delivery spec

Things you'll need figure out for your engine:

- what's the start of delivery spec? It's not 14-15 ATDC. That's the spec for the reference lug in the IP. It should be something like 20-30 BTDC.

- how do you pressurize the system? Maybe get an old carburettor type fuel pump and fit it between the fuel pump and the main fuel filter. Pump by hand to build pressure.

- does the procedure for the 617 apply to the 602?

BTW, that is the delivery valve you have circled in red in your first photo.

I recommend you search the archives for setting IP timing for the 603. Much easier and cleaner to do it using the reference lug. Again, with apologies to the techs and purists because this is not the way MB inteneded IP timing to be set.

Sixto
91 300SE
87 300SDL
83 300SD

Very clear procedure,

If I'm not wrong, all W124 diesel engines have the start of delivery ~24 BTDC ?? and the degree the locking tool engages is just a constructor choice.

Anyway, I checked my timing yesterday it was 2 degrees of.
After adjusting to the good value, the engine still smocking slightly. and the phenomenon that disturb me is the following,

When the engine is cold, it runs very wery smooth, When engine reaches operating temperature, it makes a "Tfff Tfff Tfff Tfff" noise like I have a leak in the intake air circuit.

I've checked the Exhaust & intake circuits, prechambers... no air leak, do you have any idea?

Have you checked cam timing? That will give you an indication of the health of your chain. The IP timing spec (24 BTDC of whatever) depends on proper cam timing as well.

In the US, there is an unusually high incidence of timing chains breaking on 300D 2.5 models. At least it seems high to me. Check the archives for yourself.

That sound can't be on the intake side because there's no air throttle and the intake manifold isn't pressurized at idle.

Another thing you can check, though I don't know how, is the health of your vacuum pump. It's on the front of the engine ahead of the injection pump.

Sixto
91 300SE
87 300SDL
83 300SD

My timing chain is new, The cam is synchronized whith the Cranck at TDC, 0° stretch.

I've changed the valve seats, and read an article that says that for bad valve seat we can have the phenomenon described in the attached picture. (sounds like the valves R hiting the pistons' heads I hope i am wrong )

My vaccum pump's string seems to be OK,I don't know how to check its diaphragm !!! (but no noise when cold : so i don't think that is the cause)

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How do you set the start of delivery on a 1976 240D (115 chassis)? There are not two rows of adjusters on this one, on the top, only the tubes going to the injectors. My mechanic was afraid to touch those as the manuals we had didn't identify if removing the valve and spring would also unadjust the pump. Also, where are the bolts for setting this? We think we found the big bolt in front of the injector pump, but have no documentation on it. Any help and/or pics would be greatly appreciated. Was getting unburned fuel out of tailpipe, but that is subsided, but still getting letting lousy mpg.

Vicki in MOntana

yben,

You replaced VALVE SEALS or valve seats???? Seems very strange to need valve seats. A loose one can cause some strange problems. It sounds to me like you are having diesel injector nailing symptoms.

Have you tried techron or diesel purge?

Drip timing requires constant pumping of the manual pump for continual flow. Not clearly described in the manual. For pre 1982 cars, I though bubble method was reconized as easier than drip method.

Timing pin is for 15 degrees

It's soooo easy to use the a-b indicator tool. I'd spring $50 cash money for a mechanic to do my timing in 15 minutes in the parking lot.


Michael

__________________
Michael McGuire
83 300d
01 vw A4 TDI
66 Chevy Corsa
68 GMC V6 w/oD
86 300E

Both,

Valve seats because the gap (in the attached image) was greater than the tolerance ( range : 0.1mm < a < 0.5mm ) mines were > 0.7mm, one was 1.2mm , I think that this clearance is very important in diesel engines, it affects directly the compression.

I've already used several diesel additives, and last sunday I checked my IP, result : all is OK , injectors were at 1015PSI (this was done to avoid noise : but the car leaks power) now there are set to 1450, the car runs better but is slightly noisy than before.

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Yea,

On the last 617 I did a valve job on... I replaced the intake valves to keep the clearance inspec. Got them for about $7 each, so it was easier than replacing the seats.

Why did you put the head back on the car with the clearance out of spec???? The seat needs to be cut so the valve is recessed properly in the head.

Is it the cause of your noise? I've got no idea!

Not sure what the spec on injectors is for your car... is 1450 psi correct? It sure doesn't sound right- that's 100 bars, which doesn't sound right to me.

The 617's run 115-123 bars for non-turbos and 125-135 bars for turbos. Those numbers are close, but may not be correct.

Michael

__________________
Michael McGuire
83 300d
01 vw A4 TDI
66 Chevy Corsa
68 GMC V6 w/oD
86 300E

Do you have a proper pop tester for the injectors??

Is your setup accurate for the break-pressure? Is the gauge accurate?


Michael

__________________
Michael McGuire
83 300d
01 vw A4 TDI
66 Chevy Corsa
68 GMC V6 w/oD
86 300E

I didn't put the head back with the old valve-seats, I said that, despite the fact having them replaced, I still hear the noise.

On my 602 New Injectors must be 135-145 and minimum 120 bar for used ones.

Injectors and IP were tested by a specialist.