87 300D Won't Start - Page 2 - PeachParts Mercedes-Benz Forum

babymog · #16 04-29-2008, 09:04 PM

Should start on WD-40. Where are you / what's the temperature there? Won't run well on WD, but should start if sprayed while cranking.

Is the STOP lever up?

dieseldiehard · #17 04-29-2008, 09:56 PM

did you put the crossover pipe back? I had an experience when I removed mine I couldn't start the engine. You need boost it seems to get the 603 to start.

Brian Carlton · #18 04-29-2008, 10:02 PM

Quote:

Originally Posted by reyndiesel

Brian,
Thanks for spending the time to think about this. I ended up replacing all the glowplugs. The glowplug light on the dash now comes on, though it takes a second. It still would only sputter. This is an improvement from before. It did nothing before. I have voltage to the relay, at both sides of the 80A fuse, and the pins on the relay to the glowplugs have 12v. Didn't check ohms. I tried unplugging the 6 pin to the glowplugs and it won't even sputter. After all this, I checked the secondary (spin on) and it was full of little black chunks and crude around the rubber seal. I put a new filter on, filled it w/ diesel first and still, no go. I pulled the crossover and sprayed WD40, just sputters. Then I was looked at the primary filter again, and I had it on backwards, so I turned it around, arrow pointing away from the steel fuel line and toward the lift pump. Nothing. Now, though, it won't pull fuel into the primary filter. I'm stuck here. I've recharged my battery about 8 times now cranking on it. Is the IP gummed up from the crud in the secondary filter? Shouldn't it start on an external fuel source like WD40? Any help would be appreciated. I'm getting frustrated after 2 weeks of work.
Thanks,
Brad

Pull the line from the fuel pump to the secondary filter and run it into a small container. Crank the engine for 15 seconds. Report back on how much fuel is in the container.

sixto · #19 04-29-2008, 10:58 PM

Quote:

Originally Posted by dieseldiehard

did you put the crossover pipe back? I had an experience when I removed mine I couldn't start the engine. You need boost it seems to get the 603 to start.

Really? I drove an 87 SDL a few hundred feet without the crossover pipe to investigate oil consumption.

Sixto
87 300D

reyndiesel · #20 04-30-2008, 08:45 PM

There is no fuel coming from the secondary filter. I don't have anything coming from the lift pump, either. I've got an air leak or something plugged or a bad lift pump. I can't do anything more tonite, but I'll report back tomorrow. Any other ideas? Thanks for all the help so far.
Brad

Diesel911 · #21 04-30-2008, 09:43 PM

Quote:

Originally Posted by reyndiesel

Thanks for all the advice. I've cracked the injector lines at the head and I get fuel there. The strip fuse at the glow relays looks good, but I'll check it closely for cracks. Do the lift pumps get weak at this mileage? Seems like at 300,000K a mechanical pump would have to show some wear. Thanks again for all the help. I'll let you all know how it turns out.
Brad

The primary filter only has a screen to protect the lift pump. Alot of that black crud has passed through the lift pump. I dose not happen often but the valves inside of the lift pump can become caked with crud and not seal as well as they did before. Other than that it is pretty difficult do damage the lift pump. Occasionaly the little "O" ring seal on the piston rod leaks or even less often the return spring breaks.
I would check the Glow Plugs as Brian suggested,change the secondary filter again and get a container of clean diesel and run a hose from the lift pump to the clean diesel to start the car. If it starts OK I would do something to clean out the fuel tank or you will be changing alot of filters.

Diesel911 · #22 04-30-2008, 09:56 PM

Is there a hand primer on his 87 model?

Bio300TDTdriver · #23 04-30-2008, 10:02 PM

Quote:

Originally Posted by Diesel911

Is there a hand primer on his 87 model?

No, the OM603 self primes. With lots of cranking if the fuel filter is not filled.

probear · #24 04-30-2008, 10:09 PM

Will any fuel freely drain from the line from the tank to the primary filter. Just disconnect and see how much will free flow for about a minute. It should come out in a flow, not a dribble. If not, then loosen or remove the fuel tank cap, and check it then. Sometimes a plugged vent line will create a vacuum on the tank.
With my 87 SDL, I had to remove and clean the tank screen, but it was a slow degeneration of power.

bustedbenz · #25 05-01-2008, 11:18 AM

Just for fun, take the fuel tank cap off and try to start it and/or get better fuel delivery. I find it hard to imagine you're pulling that much of a vacuum on the tank... but it's theoretically possible.

dieseldiehard · #26 05-01-2008, 09:47 PM

Quote:

Originally Posted by sixto

Really? I drove an 87 SDL a few hundred feet without the crossover pipe to investigate oil consumption.

Sixto
87 300D

Yup! I was shocked when it happened. I replaced the crossover and it became a live engine again.

VeeDubTDI · #27 05-01-2008, 11:14 PM

Have you visually checked the glowplugs to verify that they are in fact operating and getting hot? Remove one (or more) from the engine and energize them and watch to see that they glow red.

I should note that I don't think that the glowplugs are your problem (but it is a good idea to rule it out anyway).

I think that your problem is a fueling issue. Perhaps a clogged tank pickup screen, or something of the sorts. A friend of mine had this problem on his old 300D when he got a batch of bad biodiesel that had algae growing in it like a swamp.

It totally plugged up his entire fuel system with black death.

Best of luck!

reyndiesel · #28 05-05-2008, 10:07 PM

I pulled the line from the primary filter and ran a fuel line into a little can of clean diesel. It doesn't pull anything out of the can. Also, if you hold your finger over the end of the line, nothing, no suction, nada. The fuel goes thru the primary, into a fuel regulator and then into the lift pump, correct? I want to make sure it is the lift pump before I replace it. I don't want to just throw parts at it and hope I can fix it. As for the glowplugs, I just replaced them. Thanks for all the help, so far.
Brad

sixto · #29 05-05-2008, 10:12 PM

Do the same test with the line that goes from the fuel thermostat to the lift pump to determine if there's a blockage in the fuel thermostat.

Sixto
87 300D

reyndiesel · #30 05-11-2008, 09:06 PM

OK, finally got a line from the lift pump to a clean can of diesel. The lift pump is pulling some fuel up. If you hold your thumb over the end of the line going into the lift pump it will pull some, not alot, though. I ran the battery down again, so I'm waiting for it to charge. How much vacuum should the lift pump pull? I haven't had time to work on the car, so it is taking me longer than I thought. Thanks again for all the help.
Brad