MB E300TDT s210 new o-rings, new full Lines, won't start... - PeachParts Mercedes-Benz Forum

Preben · #1 09-17-2013, 04:46 PM

Hi, I have a MB E300TDT 1998 s210 that now has new full Lines all the way to the diesel suction pump. The other fuel lines and the stop valve has new o-rings.

I have then pre-filled the diesel system by pressurizing the diesel tank with an air compressor, and then opening the fuel line between the diesel suction pump and the main diesel filter. This has forced the air out, and I can see diesel in all the affected lines.

Yet, the car will not start.

Just to check I have loosened the injector lines a little, and no diesel comes when cranking the engine.

I now need help: what do I do next?

TMAllison · #2 09-17-2013, 08:40 PM

Quote:

Originally Posted by Preben

Hi, I have a MB E300TDT 1998 s210 that now has new full Lines all the way to the diesel suction pump. The other fuel lines and the stop valve has new o-rings.

I have then pre-filled the diesel system by pressurizing the diesel tank with an air compressor, and then opening the fuel line between the diesel suction pump and the main diesel filter. This has forced the air out, and I can see diesel in all the affected lines.

Yet, the car will not start.

Just to check I have loosened the injector lines a little, and no diesel comes when cranking the engine.

I now need help: what do I do next?

Stop opening the lines. Just lets air in and loses what prime you had.

Hood up, Drivers window down, turn key to pos 2 and listen for the click of the shut off value opening. No click, no start. Ever. If it never clicks open, replace the K40 relay. Still doesn't click open, replace the shut off valve.

Fill the pre-filter and spin on filter with fuel. Charge battery fully. Manually crank 30 sec's, wait 2 mins, crank 30 secs again. Repeat. Repeat, repeat, repeat. Recharge battery. Repeat, repeat, repeat, and repeat again.

If it ever starts to crank faster as if it might catch, keep cranking and DO NOT stop until is guaranteed it is running. It won't hurt the starter as long as you let go of the key a couple secs after its running.

If none of that works, confirm you didn't throw the prefilter oring away when you replaced it (might want to do this first) and then replace the crank position sensor and start priming again.

Stop opening the sealed system........it works off suction. Every time you open it up, it loses all vacuum.

Preben · #3 09-18-2013, 03:17 AM

Should I hear the click in the SOV, or else where? I hear a click when I turn the key, but it might be the glow plugs may be?

I am not opening the lines after priming them with high pressure in tank.

What happens amazes me: the fuel is not pumped through the line between the diesel heater and the pre-filter. It is a standing air bubble in there. Should I still crank on (am afraid I can hurt the fuel lift pump ???)

Can I somehow take the SOV off and test it?

(My battery seams to have had it. A new one costs lots! - I still don't understand why Mercedes has made this stupid "crank it for 3 months before it starts"-solution in stead of the good old manual pump to get the air out.

Preben · #4 09-18-2013, 03:20 AM

PS: I can confirm that I have a new o-ring for the pre-filter. I also checked the screw and the metal bit that forces the fuel line and the pre-filter together.

Preben · #5 09-18-2013, 08:34 AM

I have now succeeded in getting diesel all the way through to the SOV.

I have almost no air bubbles in the lines, and have also now loosened the injector lines a little from the injectors to get air out.

Now there is a little diesel coming out, but VERY LITTLE. Isn't the injector lines supposed to "spray" out diesel with high pressure?

My injector line for injector #1 is almost dry.

Can the SOV be a problem (opening just a little?) Or can there still be a lot of air in the injector diesel pump?

Preben · #6 09-18-2013, 02:17 PM

Seams like the SOV might be the problem. Or actually the system that sends power to the SOV.

read more here (new thread): Shut off valve not working - low voltage error?

TMAllison · #7 09-19-2013, 10:52 AM

Whenever the engine is off, the fuel line from the prefilter to the fuel thermostat drains back an inch or two. That's normal. If you have a sealed system and a working lift pump, that line will fill instantly when you begin to crank.

You should hear a good strong click from the side of the IP when you turn the key to position #2. No click, no start.

After cranking a few times, stop and refill both fuel filters, and charge the battery during that time. If it spins faster, coughs and catches for a moment, do not let off the key. Keep cranking until you are 100% certain its running.

Preben · #8 09-19-2013, 11:13 AM

The problem now seems to be that the voltage to the SOV is too low.

What can cause that?

When key is put to position 2, there is a very short connection. The voltmeter shows about 3V for milliseconds. Then 0 V

If I put 12 V directly to the SOV it works well.

Zulfiqar · #9 09-19-2013, 12:50 PM

that sounds like the K40 relay problem, its the main big block that itself is a bunch of relays. Let a diesel owning W210 member post.

TMAllison · #10 09-19-2013, 08:34 PM

K40 provides power to the SOV, and numerous other devices.

Preben · #11 09-20-2013, 02:33 AM

I have opened what I assume is the K40, but my version is NOT like the others I have seen on net.

It has the number A 000 540 01 72 (edit: found a link to similar: http://mbspecialist.com/mercedes_webcatalog/item/0005400172B/ )

Is this a K40 relay?

It seams I only can take off a lid underneith, and in there I see a printcard (but not the releys). The printcard has NO sign of burn etc. No bad electronic smell neither.

Is there a way I can test this an easy way?

TMAllison · #12 09-20-2013, 10:57 AM

That is the K40 relay. Always has 540 in the part number.

To determine if it is responsible for elect faults you need to use a very strong magnifying glass or microscope and view the entire circuit board for minute cracks which can open and close when the board expands and contracts.

Is easier to just replace it. If its not bad now, it will be one day in the future. Your old one could go into your tool box in reserve.

Preben · #13 09-20-2013, 11:34 AM

I have a E290 TDT also and found that it has the same relay. Tried that, same error. But my 290 starts. So I started to investigate more.

Found that the connection between the SOV and the plug was very fragile. Have now cleaned it with electronics spray. Still not great connection, but if I press it, it connects and the SOV is now working.

Next will to press diesel through the system, and then try to start.

I guess that the start problems have been related to a mix of air in the system and an "on /off" error with the connection.

Have taken me MANY hours.

So I hope it'll start later when I try. :-)

jay_bob · #14 09-20-2013, 01:43 PM

Keep in mind that the SOV has to be continuously energized in order for the car to run. If the connection breaks, the car will die.

Either you have a bad plug/socket connection or there is a broken connection inside the SOV that makes up when you push on it.

At least you got the fuel side sealing all sorted out, it ought to run smooth as silk whenever you do manage to get the fuel solenoid working...

Preben · #15 09-21-2013, 08:30 AM

The car started!

It has been a combination of bad connection to the SOV, and an air leak.

After the air leak was fixed (new o-ring inside the SOV) , the diesel didn't go to either the suction pump or the injector pump, as the SOV stopped the diesel.

Sometimes the connection worked, and the car started. But stopped again when the movements in the car made the connection break.

So now it works, and it is kicking strong again :-)