Ok guys, I really need help. My wife said if the Mercedes is not fixed by the weekend, she is getting an echo.

Car:
1979 300sd

Situation:
Car would not go over 20 mph but starts up right away. Primary fuel filter already changed. Feels like fuel restriction. Thinking, well change the secondary filter and should be fine. Changed the secondary and will no longer start.

What I have done:
"primed" the secondary fuel fiter.
Cranked till dead battery.
Verified fuel is going to the IP assembly.
Verified fuel is not getting to the injectors (cracked one of the lines, tried to start, not a drop comes out)

So it appears that fuel is not getting through the IP pump assembly. I dont think it is bad, because it worked right before changing the fuel filter - unless that is what was making it only go 20 mph.

So I guess my question is, is there a way to prime the injection pump? Is there a vacuum hose I may have accidently unplugged when changing the secondary filter? Or could it possibly be that my issue is the IP pump, and that is what was also causing the 20 mph speeds. Thanks!

Unplug the vacuum hose from the shut off valve at the back of the IP to exclude the possiblity that there is a problem in the ignition switch causing the vacuum to the shut off valve to not fully release.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

First things first:

Are you running WVO or Diesel?
Which primer pump do you have?
What do you mean when you say you primed the filter?
When it was running, and going 20, any signs of smoke?
If so, what color?

That should get everyone to a good start.

Since the fuel is getting to the IP, crack all your injector lines, and start cranking away. If the IP is OK, you should have fuel coming out of ALL those lines. If not ALL those line, the problem is inside you IP.

__________________
1989 300E 144K

[QUOTE=mrwvo;1426699]Ok guys, I really need help. My wife said if the Mercedes is not fixed by the weekend, she is getting an echo.

Car:
1979 300sd
Try to enjoy driving around in your new echo. It does take a little getting used to. At least you get fair warning. I am usually not that fortunate.

Did you fill the new filter with diesel and use the primer pump until fuel flowed out of the loosened top bolt on the secondary filter? If so tighten up the bolt on the secondary filter and crack all of the injector lines until you get fuel at each one then tighten them up.

__________________
1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine

I am running diesel - no veggie oil

I have the old style primer pump - and know that its working because it pumps fuel to the ip, just not out to the injectors.

When I say primed the filter, I mean I filled it up with diesel.

When it was running at 20 mph, it was working great. No abnormal smoke or anything. Just felt a slowdown and loss of power - like i was running out of gas.

BJKAST -
Yes, I am getting fuel out of the top bolt. I cracked the injectors, and no matter how much I pump or crank the engine, not a drop comes out of the injector lines. That is what I dont understand. Especially since it was working (slow but working) and now not a drop comes out. Thats why I was wondering if I needed to prime the IP somehow to get the fuel moving.

Thanks again all.

See post #2.

__________________
Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)

I had a simalar problem with my diesel S10 when I first got it running, might try cracking the injector lines and making sure there's no air in there, once you do get it running again if it wont go over 20 try filling the filter with Seafoam and run it on that for a wile my S10 wouldnt go over 40 after a can of seafoam threw the IP it would go 70 stuff works wonders

I second the dissconect the vacuum shutoff for now. you should not need to prime the IP,
Try these things.

please open your fuel tank cap, do you hear a whoosh.

Loosen the banjo bolt at the back of the ip, when you pump the primper does fuel come out.

The only time i have had a similar problem i when i had a bad primer pump, and a secondary fuel filter full of air. Lots of cranking, and praying to start. when it finally did, I kept the revs up, make sure your primer is sealed and not sucking air.

goodluck

__________________
1984 Euro 300SDC, (4spd standard)
1986 Toyota Landcruiser Diesel HJ60 5spd X2

Gone but not forgotten (some sold, some stripped)
1983 300 SD, 1985 300 SD, 1983 240D, 1986 300 SDL, 1985 300 SDL, 1983 300 D, 1984 300 D, 1985 300SD, 1987 300 SDL, 1983 300 SD, 1985 300 TD Euro, 1983 380SEC, 1990 300 D, 1987 300D, 1982 300D, 1982 300D, 1994 E420, 1987 300 TD, 1987 300 D, 1984 300 D

Ok disconnected the vacuum shutoff valve, no help.

Already had the cap off to the tank, but I know where your going as far as clogged fuel vent

Loosened the bango bolt, fuel does come out when priming.

Cracked injectors, not a drop comes out

I cant believe I thought my filter change would be a 5 minute quick change lol.

So would the best suggestion be to keep cranking? If I crack the injector, and push the primer pump, should fuel eventually come out or will the injector only pump fuel when cranking the engine?

Thanks

How long did you crank it over before determining there was no fuel to the injectors? It takes about 12 seconds which can seems like an eternity when your cranking I would charge up the battery good and try it again. Wouldn't hurt to replace your primer pump if its leaking.

fuel wont come out at the injectors by using the priming pump.

__________________


1985 Euro 240D 5 spd 140K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"

Sounds to me like you got a good dose of air in the IP and lines.

I suggest you depress the throttlefully cranking till it starts to fire,

__________________
1984 Euro 300SDC, (4spd standard)
1986 Toyota Landcruiser Diesel HJ60 5spd X2

Gone but not forgotten (some sold, some stripped)
1983 300 SD, 1985 300 SD, 1983 240D, 1986 300 SDL, 1985 300 SDL, 1983 300 D, 1984 300 D, 1985 300SD, 1987 300 SDL, 1983 300 SD, 1985 300 TD Euro, 1983 380SEC, 1990 300 D, 1987 300D, 1982 300D, 1982 300D, 1994 E420, 1987 300 TD, 1987 300 D, 1984 300 D