No start after fuel filter change - PeachParts Mercedes-Benz Forum

jtrnw · #1 03-18-2018, 08:33 PM

My 73 220d motor that I just swapped in to my 69 220d started and ran after the install. It started probably 5 different times, I drive it three times. It may have taken a smidge more cranking that I'd like, but not excessive. Otherwise it ran just fine. Then I decided to change the fuel filter. When I put the new filter in I was gonna run it on diesel purge, just for good measure. I replaced the filter and connected the fuel system to a gatorade bottle of diesel purge, the bled the system (fuel at all 4 injector nuts). Now she won't start. She kinda maybe tries on one cylinder, but that's all. So I thought well maybe this diesel purge stuff doesn't light off as well as regular diesel, so I drained and replaced it with regular diesel, reprimed, still no starting. Last night I got a friend to help and we tried starting it on wd40, the engine didn't even seem to notice it.

So I really don't understand. Since the wd40 didn't work that makes it sound like a compression issue, but absolutely nothing but the fuel changed, so I'm loath to believe that. I could take a crack at adjusting the valves, etc. I just don't like the idea of messing with things that were working. Any thoughts?

Father Of Giants · #2 03-18-2018, 08:59 PM

Did you fill the fuel fliter up, is your foot to the flour while cranking, are there any leaks?

Dubyagee · #3 03-18-2018, 09:10 PM

Quote:

Originally Posted by Father Of Giants

Did you fill the fuel fliter up, is your foot to the flour while cranking, are there any leaks?

Foot to the flour. That visual made me laugh. Ha

jtrnw · #4 03-18-2018, 10:16 PM

Quote:

Originally Posted by Father Of Giants

Did you fill the fuel fliter up, is your foot to the flour while cranking, are there any leaks?

Yup foot to the floor, no leaks that I've seen yet.

leathermang · #5 03-18-2018, 10:54 PM

I would stay with the fuel thing since that is what you messed with and things changed..
but see if all the vacuum lines are still where they should be .. did you have the lever tied up during any of this..
I like the Diesel Purge.. but I just waited until I was low on fuel.... filled the filter..and put the rest into the tank.... the gatoraid bottle I don't know how that is necessary.... stay with the basics... just keep looking until you figure it out.. don't jump to something else like compression yet..... but that is an interesting test result.....

NZScott · #6 03-18-2018, 11:32 PM

I think where you went wrong was bleeding at the injectors. Changing the fuel filter doesn't put air into that side of the IP elements unless the engine was cranked while no (fuel filled) filter was present. You only need to bleed the inlet to the IP when changing filters - bleeding the injectors at a wild guess dragged some air into the IP inlet while you were getting fuel out the other end and thinking it's ok. I've never done the WD40 thing, I wouldn't base conclusions on it myself.

Just a guess...

dieselbenz1 · #7 03-18-2018, 11:37 PM

Did you put both supply and return lines into the gatorade bottle? Did you see any air bubbles coming out the return line?

jtrnw · #8 03-19-2018, 11:29 AM

Quote:

Originally Posted by NZScott

I think where you went wrong was bleeding at the injectors. Changing the fuel filter doesn't put air into that side of the IP elements unless the engine was cranked while no (fuel filled) filter was present. You only need to bleed the inlet to the IP when changing filters - bleeding the injectors at a wild guess dragged some air into the IP inlet while you were getting fuel out the other end and thinking it's ok. I've never done the WD40 thing, I wouldn't base conclusions on it myself.

Just a guess...

So the reason I needed to rebleed at the injectors is I took the lines off at the pump. I changed filter housing. Otherwise yes I wouldn't have had to.

Quote:

Did you put both supply and return lines into the gatorade bottle? Did you see any air bubbles coming out the return line?

Yes, and I didn't see bubbles when pumped the hand primer, but its hard to see while I'm in the car cranking.

leathermang · #9 03-19-2018, 01:12 PM

Bleeding AT the injectors is a good way to tell bottom line if you are getting fuel to the injectors....
An vapor lock can exist before the high pressure pump...
I think an extra person to run the ' key' to crank the engine while you are cracking each injector just long enough to check for fuel is a good plan. I have to do this by myself once in while out in the field on my 5600 diesel tractor.... when I run out of fuel due to a non working tank monitor.... it is 40 years old.. lol .. reaching the key and the injectors at the same time is not easy... and dangerous... if the tractor is in gear it will run over me.... farmers die like this all the time...