Fuel filters changed, now no start! What did I do wrong? - PeachParts Mercedes-Benz Forum

Merkey · #1 11-25-2009, 10:28 PM

My 190D was leaking fuel from the fuel return lines from the Injectors.
I found the right hose locally and replaced the lines.
While I was under the hood I replaced the 2 fuel filters... the inline and the canister. The canister one looked slightly bigger diameter (Its a Mann 817/3), than the one I took off, but the seal surface was the same diameter and I was told it was the right one. The only thing I noticed now was the filter did not come with new bolt seals or a crush washer for the head of the bolt...

The inline was installed with the arrow on it pointing toward the pump, and it seemed to fill with fuel.

Now it wont start....
Thinking I did something wrong, I swapped the old filters back in..
No start still.
I was worried that I was low on diesel as the gauge was almost on empty, so I put 5 gallons in.
Still no start.
Am I missing something?

tbomachines · #2 11-25-2009, 10:34 PM

Did you prime it after replacing them? You'll probably need to pump it aboout 100X if you did not prime the spin-on.

Aquaticedge · #3 11-25-2009, 10:34 PM

sounds like air, did you yourself fill the filters with diesel?

Merkey · #4 11-25-2009, 10:42 PM

No...

What do I do now?

Aquaticedge · #5 11-25-2009, 10:43 PM

Prime the hell out of it, someone will have to give you directions... make sure you have the new filters in there too.

Merkey · #6 11-25-2009, 10:45 PM

I feel stupid... how do you prime?

WhoWhat · #7 11-25-2009, 10:55 PM

Quote:

Originally Posted by Merkey

I feel stupid... how do you prime?

On the driver's side of the engine, look down below/behind the power steering pump. You'll see (most likely) a round, white cylinder, about the diameter of a half dollar. (If that pump's been replaced, it will be black, and a little smaller)

Pull that white cylinder - it's the manual/hand primer pump. Pump it probably 50 or 60 times (no joke). You should be able to see the small, clear fuel filter fill with fuel as you pump.

If that cylinder is black, then it's a spring loaded "button" style...just press it down, and it will pop back up automatically. Do that a BUNCH of times.

Either way, pump it forever...then crank the engine (after glowing the plugs, of course).

EDIT: just noticed you have a 190D. My instructions are for my OM617 engine...probably similar set up for your car too.

wannadiesel · #8 11-25-2009, 11:00 PM

I did the same thing on my 300sd.

I ending up taking the filter off and filling it with a mix of atf and veggie oil (didnt have any diesel available). You will have to prime it alot if its bone dry.

Merkey · #9 11-25-2009, 11:01 PM

My 190D manual says that the pump is self priming...
I will go look...

MercFan · #10 11-25-2009, 11:12 PM

I just completed this job myself - we have different engines, but my pump is self-priming as well, so I'll try to assist a bit.

It's probably not too late to remove the spin-on filter and fill it up with either clean diesel fuel or PowerService - make sure it's as full as it can be (overflowing even) before you snug the top bolt. Try starting again - it helps to have a warm engine, so if you can afford to wait and you have an engine heater I'd plug it in for a couple of hours before you crank again.

It may and should start when you fill up the filter, and if not, I'd crack the injection lines on top of each injector and then crank - this should purge it of all air that's in the hard lines. It's easier to do this with a helper - that way one can crank and the other can snug the hard fuel lines when the motor starts.

Good luck

Crazy_Nate · #11 11-25-2009, 11:14 PM

If it's self priming, there's no hand pump. The secondary filter takes quite a bit of fuel (I'd fill it). You can loosen the bolt and then use a tube to get it most of the way full. Much less headache.

To 'prime it', you crank the engine...in short sessions, to not burn out the starter. With a full secondary and an empty primary (clear plastic inline), it took about 2 10-second cranking intervals before I was getting fuel to the injectors.

compress ignite · #12 11-26-2009, 02:40 AM

Moeller # 34690-10 inline primer bulb
'Put it in the fuel line between the Hard Metal Fuel Line [from the Tank] and
the Primary Filter.
[Now .'Would also be a great time to Bypass the Fuel Thermostat]

Merkey · #13 11-26-2009, 02:51 AM

Looks like I got something else going on...
I went to replace the "old" inline filter with the new one and I feel 2... yes 2 pipes with open mouthes...
At first I thought I musta pulled another one off., but then I began to wonder....

Ok, so one of them is attached to the fuel pump and points down, and the other is on a seperate part... I looked in the manual..... Its called the fuel thermostat.
Now, The normal place that the pipe from the tank connects to is at the front of the fuel thermostat, and then there is a pipe from the lower rear of that same unit unit that feeds into the fuel pump...
I swear that it looks like the fuel thermostat was bypassed, and feeling around the inlet pipe on the fuel thermostat feels loose...
Here is a pic... I hope it makes sense...

So, in the Mercedes Manual, the fuel flows from the Tank, thru the metal lines, then thru the Inline fuel filter into the front of the Fuel Thermostat...(Where I pointed out the vacant inlet)
From there it goes to a heater if needed and flows back into the Fuel thermostat body and out of point D into the fuel pump at point B....

No way was my car like this.... I think someone bypassed the thermostat.
Now I assume (looking at the orientation of the pipes) That the fuel flowed straight into the fuel pump!

Merkey · #14 11-26-2009, 02:53 AM

Compress...
I was writing my post while you posted!

stcbenz83 · #15 11-26-2009, 12:19 PM

Just keep your accelerator depressed fully and crank the heck out of it. Leaving enough rooom in between cranks for starter and battery to recover. Took my once 2 days to get my 300D fired up after a filter swap