At my wit's end ( 300D suddenly doesn't want to start ) - Page 2 - PeachParts Mercedes-Benz Forum

fender_bender · #16 04-06-2013, 01:01 PM

It's the only time you are upset that something is working properly.

Stretch · #17 04-06-2013, 01:24 PM

Quote:

Originally Posted by skalie

Yes, yes and yes.

Was really hoping that it would have been something simple like that, but the injectors sprayed on to the motor when I had them externally connected, which sort of rules out those factors.

The troubleshooting on this one has been a succession of "damn, that's working", "damn, that's working as well".

Can I ask a time-line related question?

When did you do the valve adjustment - before the problems?

====>

What would probably be called a red neck solution here => have you tired WD40 in the air intake (remove air filter first!)

skalie · #18 04-06-2013, 01:38 PM

Quote:

Originally Posted by Stretch

Can I ask a time-line related question?
When did you do the valve adjustment - before the problems?

After, I took the tappet cover off to see if I could spot anything wrong, then thought, well while I'm here.

Quote:

Originally Posted by Stretch

What would probably be called a red neck solution here => have you tired WD40 in the air intake (remove air filter first!)

Yep, brake cleaner in the inlet manifold.

But ........ that reminds me of one thing, we removed the L-shaped hose, from the top of the tappet cover to the inlet manifold, the one whose diameter is the size of a euro or so, and the turn over was remarkably different, as if the timing was backwards or something.

I was surprised that one little hose could make that much difference, we attached it again, things went back to normal, and I forgot about it. I've got no idea if that's somewhat normal behaviour, and I'm not sure if my fellow redneck had already sprayed in brake cleaner at that point.

Stretch · #19 04-06-2013, 01:51 PM

Quote:

Originally Posted by skalie

...

But ........ that reminds me of one thing, we removed the L-shaped hose, from the top of the tappet cover to the inlet manifold, the one whose diameter is the size of a euro or so, and the turn over was remarkably different, as if the timing was backwards or something.

I was surprised that one little hose could make that much difference, we attached it again, things went back to normal, and I forgot about it. I've got no idea if that's somewhat normal behaviour, and I'm not sure if my fellow redneck had already sprayed in brake cleaner at that point.

That hose sounds like the crank case breather - goes from the valve cover to the air filter right?

You should be able to repeat the same effect by removing the oil filler cap.

In what way was the "turn over" different?

(Faster cranking speed I assume)

Stretch · #20 04-06-2013, 01:53 PM

Quote:

Originally Posted by skalie

After, I took the tappet cover off to see if I could spot anything wrong, then thought, well while I'm here.

...

Well - not to sound rude - it was mentioned before you did adjust them correctly now didn't you? Pop quiz => first valve you meet at the front of the engine is...

skalie · #21 04-06-2013, 02:41 PM

Quote:

Originally Posted by Stretch

That hose sounds like the crank case breather - goes from the valve cover to the air filter right?

You should be able to repeat the same effect by removing the oil filler cap.

In what way was the "turn over" different?

(Faster cranking speed I assume)

Ha ! You knew I had just enough daylight to throw in the battery and check that. Took off the oil filler cap, turned over as normal. Must have been the spray that was making it sound weird the other day.

And regarding your tappet question, according to my oil covered checklist the first valve should be a .30, exhaust.

dude99 · #22 04-06-2013, 02:47 PM

Have you tried pulling the brown line off the shutoff actuator?

Zacharias · #23 04-06-2013, 03:06 PM

Quote:

Originally Posted by skalie

No discernible smoke at all.

Extended cranking with no smell of diesel out the tailpipe and no unburned diesel mist/smoke = you aren't getting any fuel to the injectors (or the exhaust is blocked).

Do you have the old or new style primer pump? If the old type is in there (white knob that unscrews to use) this type of no-start behaviour can occur suddenly if it starts to leaks in air.

If that isn't the case, and you have the new style black pump, try pumping it at rest and see if you feel any resistance. I wager you may discover you're pumping air.

Did you by any chance change the fuel filters at some point during this exercise? It is possible to get a stubborn air lock condition afterwards, even if you think you purged the air from the system.

skalie · #24 04-06-2013, 03:07 PM

Quote:

Originally Posted by dude99

Have you tried pulling the brown line off the shutoff actuator?

Do you mean the vacuum shutoff ?

I was curious as to whether the default state would be "run" or "stop" if the vacuum was faulty ( and it is, sometimes not wanting to turn off, usually when I've forgotten to turn down the manual idle control on the dash )....

.... but I had sort of eliminated that as being a possible cause as fuel is spurting out of the injectors on turnover.

Zacharias · #25 04-06-2013, 03:20 PM

Quote:

Originally Posted by skalie

Do you mean the vacuum shutoff ?

I was curious as to whether the default state would be "run" or "stop" if the vacuum was faulty ( and it is, sometimes not wanting to turn off, usually when I've forgotten to turn down the manual idle control on the dash )....

.... but I had sort of eliminated that as being a possible cause as fuel is spurting out of the injectors on turnover.

Vacuum is applied to the shutoff valve to move the lever for shutdown, so the default position with no vaccum should be 'run'.

See my previous reply about the fuel....

skalie · #26 04-06-2013, 03:24 PM

Quote:

Originally Posted by Zacharias

Extended cranking with no smell of diesel out the tailpipe and no unburned diesel mist/smoke = you aren't getting any fuel to the injectors (or the exhaust is blocked).

.... fuel is getting to and through the injectors, although that hasn't been tested while the injectors are in the block, so the diesel they are getting might not have enough pressure to open them when compression comes into the equation.

Quote:

Originally Posted by Zacharias

Do you have the old or new style primer pump? If the old type is in there (white knob that unscrews to use) this type of no-start behaviour can occur suddenly if it starts to leaks in air.

If that isn't the case, and you have the new style black pump, try pumping it at rest and see if you feel any resistance. I wager you may discover you're pumping air.

I've got a black hand pump, a bit like a mini-donut, right up by the main diesel filter. Quite firm to pump, and as the pump expands again, you see diesel getting sucked into inline filter, as you would expect.

Quote:

Originally Posted by Zacharias

this type of no-start behaviour can occur suddenly if it starts to leaks in air.

...... exactly the words I want to hear, a prognosis that matches the symptoms.

If it is an air leak, it's going to be tricky to track down, I can replace what diesel lines there are after the inline filter with plastic lines I guess.

Quote:

Originally Posted by Zacharias

Did you by any chance change the fuel filters at some point during this exercise? It is possible to get a stubborn air lock condition afterwards, even if you think you purged the air from the system.

I changed all the filters a few months ago.

It could be an airlock however, caused by originally not having pre-glow ( a couple of wires have been tightened since the car first wouldn't start ) followed by flooding, followed by random acts of troubleshooting. Hopefully the tow start tomorrow will get it up and running and purge an air lock should it exist.

Mölyapina · #27 04-06-2013, 04:04 PM

Quote:

Originally Posted by skalie

Yes, yes and yes.

Was really hoping that it would have been something simple like that, but the injectors sprayed on to the motor when I had them externally connected, which sort of rules out those factors.

The troubleshooting on this one has been a succession of "damn, that's working", "damn, that's working as well".

...you didn't actually run the car with the injector out of the block, right? This would be a very bad idea -- The injectors spray fuel at 1950 PSI new, and while these certainly wouldn't be doing that anymore, they could still pierce your skin and introduce diesel into your bloodstream -- a very dangerous thing.

Zacharias · #28 04-06-2013, 04:09 PM

Quote:

Originally Posted by skalie

.... fuel is getting to and through the injectors, although that hasn't been tested while the injectors are in the block,

If it is an air leak, it's going to be tricky to track down, I can replace what diesel lines there are after the inline filter with plastic lines I guess.

Try cracking the hard-line connectors at the injectors and see if fuel is being delivered to the injectors when you crank.

What's the ambient temp there when you are doing all this, by the way?

skalie · #29 04-06-2013, 04:10 PM

Quote:

Originally Posted by Jooseppi Luna

...you didn't actually run the car with the injector out of the block, right? This would be a very bad idea -- The injectors spray fuel at 1950 PSI new, and while these certainly wouldn't be doing that anymore, they could still pierce your skin and introduce diesel into your bloodstream -- a very dangerous thing.

Well, I didn't want to bend the injector lines too much, so the injectors were pointing pretty much at the tappet cover, but thanks for the warning.