1982 300D won't start -- is engine turning fast enough? - Page 2 - PeachParts Mercedes-Benz Forum

leathermang · #16 09-01-2014, 06:37 AM

Quote:

Originally Posted by hawkwing

Thanks, I'll give it a shot. What's the worst that could happen?

Just follow WHunter's instructions to the letter... nothing bad will happen.

I know people who used that method FOR YEARS every time they started their car....what happened ? The car started.

hawkwing · #17 09-01-2014, 01:21 PM

Quote:

Originally Posted by funola

Your starter sounds to be on the slow side to my "trained" ear but not slow enough to not start a normal healthy engine. My healthy starter and battery spins at 180 to 190 rpm. I just saw a post of a starter at 200 rpm and a gear reduction starter at 214 rpm. Yours sounds to be around 140 rpm. Your starter also slow down then speed up at approximately a one hertz rate that mine does not do. Something in the starter or something else causing it? Can you hear it?

Thanks, I verified that it is still slow after fulling charging the battery overnight inside the house. I also hear (and feel) the 1 Hz rhythm. Is there anything other than the starter itself that might cause it to be slow/bumpy?

funola · #18 09-01-2014, 01:31 PM

Quote:

Originally Posted by hawkwing

Thanks, I verified that it is still slow after fulling charging the battery overnight inside the house. I also hear (and feel) the 1 Hz rhythm. Is there anything other than the starter itself that might cause it to be slow/bumpy?

Did the starter spin faster before this running out of fuel incident? Maybe the repeated (too long) starting attempts fried the starter? It is very damaging to continue to crank the starter when it is slowing down and you keep holding the key wishing it will start.

hawkwing · #19 09-01-2014, 03:32 PM

Quote:

Originally Posted by whunter

It sounds like the injection pump sucked serious air.
Here is a fast way to get it running again.

You need two fresh cans of WD40.
Remove the air cleaner.
Have an assistant crank the engine on command.

Spray both cans of WD40 into the intake for TWO seconds (keep spraying), and have your assistant start cranking the engine.

You should have it running within 30 - 60 seconds.
Warning: Cranking longer than 60 seconds will damage the starter.

Stop spraying if you stop cranking and/or when it begins to run on its own.
.

Alas, this did not work either. So I just pulled one of the glow plugs. It's an Autolite, covered in grease, and not glowing when I test it on the jump box :/

funola · #20 09-01-2014, 03:46 PM

For the WD40 to ignite, you need a healthy starter above 180 rpm and an engine with good compression. Just think of it this way, your injectors can atomize fuel much better than a WD40 spray can. WD40 is expensive $5 a can. I'd think you'd be much better off priming the system and let the injectors supply the fuel. Replace those glow plugs with Bosch Duraterms and also replace that starter, then your starting troubles may be over.

hawkwing · #21 09-01-2014, 06:24 PM

Quote:

Originally Posted by funola

For the WD40 to ignite, you need a healthy starter above 180 rpm and an engine with good compression. Just think of it this way, your injectors can atomize fuel much better than a WD40 spray can. WD40 is expensive $5 a can. I'd think you'd be much better off priming the system and let the injectors supply the fuel. Replace those glow plugs with Bosch Duraterms and also replace that starter, then your starting troubles may be over.

Good plan. 4 glow plugs out so far, only 1 works. This may be a problem. :0

vstech · #22 09-01-2014, 06:57 PM

Autolight plugs are bad the first time they are used in our cars... get beru or Bosch.

hawkwing · #23 09-01-2014, 07:25 PM

Quote:

Originally Posted by vstech

Autolight plugs are bad the first time they are used in our cars... get beru or Bosch.

Yes it seems so. Of the 5 that were in, only 2 worked. Interestingly, there were two different models of Autolite's in there, a seemingly older style (guessing based on wear) that has a larger gap at the wiring thread and a flat heating element, and a newer style with a tapered heating element. The two older ones worked, the three younger one didn't.

cooljjay · #24 09-01-2014, 10:51 PM

Its funny, I hear all the horror stories of autolites and I believe them...but back before I knew any better, I installed them in my euro...They have been working find for 7 years, but its been mainly in California....so the test will come the winter here...

funola · #25 09-01-2014, 11:42 PM

Quote:

Originally Posted by hawkwing

Yes it seems so. Of the 5 that were in, only 2 worked. Interestingly, there were two different models of Autolite's in there, a seemingly older style (guessing based on wear) that has a larger gap at the wiring thread and a flat heating element, and a newer style with a tapered heating element. The two older ones worked, the three younger one didn't.

You are lucky the autolites burned out on you instead of continue to work, where the tips erode with time and eventually falls off. In open pre chambers, the dropped tip fall into the combustion chamber and destroys the head and piston. The 617 has closed pre chambers with small drilled holes and a dropped tip will not fall into the combustion chamber but will bounce around an wreck the pre chamber.

whunter · #26 09-02-2014, 12:12 AM

Quote:

Originally Posted by hawkwing

Yes it seems so. Of the 5 that were in, only 2 worked. Interestingly, there were two different models of Autolite's in there, a seemingly older style (guessing based on wear) that has a larger gap at the wiring thread and a flat heating element, and a newer style with a tapered heating element. The two older ones worked, the three younger one didn't.

The burned / melted end of your glow plugs is not good = wear factor.
I test / save the functional ones and give them to owners in dire financial situations.
Under no circumstances will they go back in my personal vehicles.

I will WARN you, don't over tighten the 8MM glow plug nuts.
The threaded stud is directly attached to the heating element = over tightening will distort, stress, and/or break the NEW glow plug heating element.

Stop tightening at the first sign of wire terminal movement, this is an electrical connection measured in very low inch pounds of torque.

Here is more data than you need on the topic of glow plugs.
Glow plugs link thread

.

hawkwing · #27 09-03-2014, 02:42 AM

Quote:

Originally Posted by whunter

The burned / melted end of your glow plugs is not good = wear factor.
I test / save the functional ones and give them to owners in dire financial situations.
Under no circumstances will they go back in my personal vehicles.

I will WARN you, don't over tighten the 8MM glow plug nuts.
The threaded stud is directly attached to the heating element = over tightening will distort, stress, and/or break the NEW glow plug heating element.

Stop tightening at the first sign of wire terminal movement, this is an electrical connection measured in very low inch pounds of torque.

Here is more data than you need on the topic of glow plugs.
Glow plugs link thread

.

Thanks for the tip and the extensive reading list!

Unfortunately still not starting, think I need to move on to the starter but super not looking forward to doing it myself.

I also accidentally sheared off these vacuum line connectors when removing glow plugs. I've peeked at some vacuum diagrams but I do not yet speak Vacuumese. Can anyone tell me what this thing I broke is called?

whunter · #28 09-03-2014, 03:03 AM

Quote:

Originally Posted by hawkwing

Thanks for the tip and the extensive reading list!

Unfortunately still not starting, think I need to move on to the starter but super not looking forward to doing it myself.

I also accidentally sheared off these vacuum line connectors when removing glow plugs. I've peeked at some vacuum diagrams but I do not yet speak Vacuumese. Can anyone tell me what this thing I broke is called?

The large black vacuum line is supply from the vacuum pump to brake vacuum power booster.

The barb is vacuum supply for transmission, climate control, central locking, engine vacuum shutoff, EGR.

You need to repair or replace it.

.

Skippy · #29 09-03-2014, 06:29 AM

I bought a new one from this site. It's only like 30 bucks and it easy to install.

Edit after rereading the whole thread: If you put all new plugs in and they're working properly you should be able to start if your engine is healthy. I'd do a valve adjustment next. If they aren't done the valves get tight. Eventually they get to where they don't fully close and bleed off compression resulting in a no start. You can get the special wrenches off this site. They will pay for themselves the first time you use them.

That will probably get you driving again. To address the slow cranking speed check out the starter wiring and grounds (especially grounds) before condemning the starter. You'll want to get full cranking speed to get reliable starts in Alaska. I've never dealt with super cold weather, but I think between a block heater, new glow plugs, new battery, (presumably) good compression, and a good starting system, you should be able to start reliably well below zero. I'm sure others have more experience in this area than I. My 300D doesn't have a block heater and started with no problem down into the teens. I haven't had the need/chance to test it in colder weather than that.

funola · #30 09-03-2014, 10:03 AM

Quote:

Originally Posted by hawkwing

..
Unfortunately still not starting, think I need to move on to the starter but super not looking forward to doing it myself.

................

Not starting with new glow plugs? Make sure they are actually getting power with a test light or volt meter. There is a strip fuse in the glow plug relay. Make sure it is not burned out and the screws are tight and that there is no hairline crack. Take ithe fuse out to inspect under a magnifier if you have to.

So most of your glow plugs did all burn out after running out of fuel and the valves all got tight at the same time? Very strange coincidence lol.