Post Fuel pump project, no fuel to lines - PeachParts Mercedes-Benz Forum

gingerkid · #1 02-11-2013, 09:21 PM

I just finished up a project (its been 6 weeks or so), replaced fuel tank strainer, hose from tank to damper, damper to pump, new check valve, new fuel filter, new fuel line that connects damper to accumulator. Cleaned IAC valve. Refurbished my WUR (flushed with carb cleaner, new diaphragm, new o-ring...kit from Ferrari 400 - Home, seems to be a quality kit), replaced a few of the hard vacuum lines, new alternator, new harness plug to alternator. Battery was fully charged yesterday before i put it back in tonight.

No fuel seems to be making it to the injector lines. I say this because I disconnected the WUR to check and there was no signs of fuel having made it through that line.

I can hear/felt the pump run (had fiance crank the car while I behind the car), and no signs of leaks anywhere. I've gone over and checked everything I worked on several times and everything appears to be correct. There is 4 gallons of fuel I put in... seems like this should be enough to get the car started and to the nearest fuel station.

My initial thoughts are either a clog somewhere. And second, something went wrong with the WUR referb. Any ideas are appreciated.

Palolo · #2 02-11-2013, 09:46 PM

"Follow the fuel"

Crack lines/fittings backwards until you get a weep of fuel, then you'll know how far it has travelled along its path from tank to injector.

It'll give you an idea of where to focus attention and look for the simple things like airlock, backwards gaskets or check valves, etc.

gingerkid · #3 02-11-2013, 10:25 PM

that is great advice haha sounds like something an oracle would say... simple statement, yet so full of meaning.

Palolo · #4 02-12-2013, 02:37 AM

I learned it from my mentor who taught me how to diagnose and repair commercial espresso machines.

He'd aim me at a "broken" machine that wasn't putting coffee in the cup and say "figure it out".

His advice has been helpful in other flow/no-flow situations, and cracking fittings looking for that telltale weep or clearing an air lock will help you narrow your efforts.

It is amazing how a blocked orifice will mess with your system...

meltedpanda · #5 02-12-2013, 11:29 AM

did you purge the fule line of air or allow air to escape when you fired it up?

gingerkid · #6 02-12-2013, 02:12 PM

Nope, I assumed it would purge back to the gas tank. That is what I did with my 280se, but it is a D-jet. I take it this would be necessary?

meltedpanda · #7 02-12-2013, 03:03 PM

I'm with you and a DJet guy too, so I cannot say with a 100% certainty, but its worth a look and try , surely somewhere at the WUR you could bleed it ? Just be careful as the pressure , I believe can be significant

gingerkid · #8 02-12-2013, 03:12 PM

haha yes ill try not to take the hose i use to purge and look to see if I can see the fuel coming. yea I'll do some more research. first k-jet. I dont mind it so far but it does seem like there are more sensitive parts such as the WUR. I do like the metal fuel lines though!

mercmad6.3 · #9 02-15-2013, 04:46 AM

WUR on a Djet? Only Kjet had the warm up regulator.
If you have a Kjet ,turn the ignition on, and push the air flap down with your hand .
If you have air in the system this will get rid of it. once it fires and runs,go to each injector line and crack the fuel line nut and let fuel run out. When tightened up again the engine should smooth out.
Djet doesn't require bleeding because it has constant pressure while the engine is running.

gingerkid · #10 02-15-2013, 11:29 AM

Mercmad Sorry, we are talking about my kjet 350se but made a reference to not needing to purge/bleed air from fuel lines in my D-jet 280se. No WUR on my d-jet. Thanks for your steps, I will be trying these suggestions tomorrow.

gingerkid · #11 02-15-2013, 05:40 PM

welll i couldnt resist so I checked some stuff as soon as i got home from work. i disconnected the line that come in near the firewall, into the fuel distributor. As Mercmad suggested, manually pushing the "air flap" down triggers the fuel pump.... i got nothing. I can hear the pump run but no fuel or air movement. Seems to me, the issue it probably back in the fuel pump assembly. I am positive the one way valve is in correctly... what are the chanced the bolt that goes into the fuel filter is blocking flow? i know fuel is making it so that very spot because there was a minor drip of fuel there when i first poured gas into the tank, so I tightened it up.

meltedpanda · #12 02-15-2013, 06:13 PM

you do have your + /- in the right place ?

gingerkid · #13 02-15-2013, 06:17 PM

im pretty sure! the faded red wire to positive... unless the Germans do things differently?

gingerkid · #14 02-15-2013, 06:18 PM

as silly as that would be i would absolutely love it if that was the issue, seems like the easiest thing to fix.

gingerkid · #15 02-15-2013, 08:39 PM

"victory" the word i shouted when i came back into the house after the car started. the look on my fiances face was priceless... it was the "you are crazy what is going on" look. Anyways yes, I guess it was the many years working on electronics I've conditioned myself that black is always negative. Turns out the pump was indeed running backwards, which may not be a bad thing, should have helped clean it out a bit if there was any buildup. thanks meltedpanda. haha i just thanked a melted panda... who would have thought!