Fuel Filter Causing no Start? - PeachParts Mercedes-Benz Forum

Adriel · #1 07-15-2014, 11:21 AM

Changed both filters yesterday, and now when I try and leave for the mechanic, she will not start. At first it did run, but then just died. I pumped and cranked for several minutes but was only awarded a great big cloud of smoke. I made sure there was fuel in both filters and primed the system. So can a fuel filter cause a no start?

Tow should be here in about a half hour, but want to prevent this in the future, so any replies are greatly appreciated!

Skibum · #2 07-15-2014, 11:54 AM

Sounds like you still have air in the lines. Try cracking the last injector loose while you prime the system so the air can get out.

vstech · #3 07-15-2014, 01:47 PM

if you did not start with FULL secondary filter, after starting the car on the new primary, and building up fuel... then you have air in the IP, and injector lines, and need to bleed them all out.

proper way to change both filters is: replace the clear primary, then start the car, and build up smooth idle.
then shut down the car, and remove the secondary filter, with the new filter already filled with fuel, and ready to install.
install it with new o-rings on the center bolt, and crank the car, with the accelerator 1/2 pressed down to cover the stumble as air is ingested, and let up once the stumble is gone.

Adriel · #4 07-15-2014, 02:02 PM

Quote:

Originally Posted by vstech

if you did not start with FULL secondary filter, after starting the car on the new primary, and building up fuel... then you have air in the IP, and injector lines, and need to bleed them all out.

proper way to change both filters is: replace the clear primary, then start the car, and build up smooth idle.
then shut down the car, and remove the secondary filter, with the new filter already filled with fuel, and ready to install.
install it with new o-rings on the center bolt, and crank the car, with the accelerator 1/2 pressed down to cover the stumble as air is ingested, and let up once the stumble is gone.

Thank you so very much for all this help!

The mechanic pumped the primer for much longer than I did and eventually started. He said it takes more pumping than just no bubbles in the line. However, I like your method!

First, there was no O-rings anywhere. The filter was last changed by a long time Mercedes mechanic, so has me puzzled. Do you have a picture or diagram? How come things have been fine for over a year? I mean, how did I get along without them?

I changed the primary first, then saw how dirty the pre filter was. Mistake number one.

Second mistake was not holding the accelerator when it was just about to die.

Third mistake was low blood sugar. I did eat a snack once home and thus why posting now, but already feel hungry and not lunch time...

Glad you all are here to help me through all these lessons!

vstech · #5 07-15-2014, 02:04 PM

secondary fuel filter, pull the center bolt out...
depending on the year of the vehicle, there will be 1 or 2 o-rings on the bolt.

Adriel · #6 07-15-2014, 02:08 PM

Quote:

Originally Posted by vstech

secondary fuel filter, pull the center bolt out...
depending on the year of the vehicle, there will be 1 or 2 o-rings on the bolt.

Thank you so very much!

Oh! Under neath? I didn't see any but if in the housing, that explains it. Duh!

How often should they be replaced? I didn't replace the gasket on the oel filter and very much regretting it...

Diesel911 · #7 07-15-2014, 09:15 PM

Quote:

Originally Posted by Adriel

Thank you so very much for all this help!

The mechanic pumped the primer for much longer than I did and eventually started. He said it takes more pumping than just no bubbles in the line. However, I like your method!

First, there was no O-rings anywhere. The filter was last changed by a long time Mercedes mechanic, so has me puzzled. Do you have a picture or diagram? How come things have been fine for over a year? I mean, how did I get along without them?

I changed the primary first, then saw how dirty the pre filter was. Mistake number one.

Second mistake was not holding the accelerator when it was just about to die.

Third mistake was low blood sugar. I did eat a snack once home and thus why posting now, but already feel hungry and not lunch time...

Glad you all are here to help me through all these lessons!

I divide it into the Fuel Supply System and the Fuel Injection System.

If you did not fill the Secondary/Spin-on Filter with Fuel when you installed it you need to do a lot of pumping on the Hand Primer till you hear a Squealing or buzzing sound coming from the middle engine side of the Fuel Injection Pump assembly. That sound means the Air is out of the Fuel Supply System.
After you hear that sound pump some more to be sure.

If Air got into the Fuel Injection Part off the Fuel Injection Pump that is the Element and the Fuel Injection hard lines. The Air in there compresses and barley moves along. You can kill a Battery trying to crank the Air out of there.
As other said lessening the Fuel Injection Line Nuts at the Injectors and cranking the Engine allows the Air to escape fast. When Fuel starts coming out good tighten then Nuts and attempt to start.

If you Hand Primer leaks when you pump with it get a new Bosch Hand Primer.

vstech · #8 07-15-2014, 10:21 PM

The o rings should be changed each time you change the filter.

compress ignite · #9 07-16-2014, 02:05 AM

EDIT

Now, it's the correct o-ring.

Thanks vstech.

vstech · #10 07-16-2014, 08:03 AM

Quote:

Originally Posted by compress ignite

Ici !

Yes, but we are talking about FUEL filter o-rings

Diesel911 · #11 07-16-2014, 09:12 AM

I kind of doubt if many People change the Fuel Filter O-rings with each Fuel Filter Change.

But, changing the O-rings should not be a burden as long as your Fuel source has clean Fuel.

OM617YOTA · #12 07-16-2014, 09:22 AM

Thanks everyone for starting and contributing to this thread. I did not know there were O-rings on the secondary fuel filter and have never changed mine. They are probably the only bits in the fuel system that haven't been replaced.