cranks, but won't start - not getting fuel?

[jeffl]

i have an 81 240D chassis 123 123, engine 616, bought from original owner couple weeks ago. ran great for 500 or so miles, then last night it suddenly lost power and wouldn't start. i thought it had run out of gas, and the fuel gauge was not reading correctly, so i threw in a few gallons. no luck, so then i replaced both fuel filters, and still wouldn't start. i bled the system by opening the output bolt on the fuel filter and operating the hand pump until fuel got all over the place and then some. too much? didn't have any effect.. the last time i tried to start it, i turned it over for maybe 15 seconds, gave it some gas and it started, it gave off some bad smelling darkish smoke, and quit. tried once more and it wouldn't start, turns fine, but doesnt seem to be getting any fuel. glow plug light indicates no problems, turns over strong. what should i check next? injectors? fuel pump? air in the system?

i have the chilton and factory repair manuals to work from. also i have read some similar threads here, but not quite the same, so i decided to post.. anyway can't hurt to ask.

some additional info:

- car has been running a blend of 20 percent biodiesel for last few hundred miles. both fuels are astm grade.
-i began to notice a slight, irregular (but timed with one or more of the cylinders) knocking sound from the engine just after i bought it. it can only be heard at idle, it gets either drowned out or goes away with increased rpm. i assume this indicates the injectors need to be cleaned and adjusted, and maybe valve adjustment is due, but should not cause the car to die all of a sudden and not start?
-by unlucky chance, the car died on a street under construction. they are going to tow it tommorow morning, sept 7 2004, if i don't get it out of there somehow.

i appreciate very much any relevant advice!

-jeff

[leathermang]

You might need to use a tow rope and pull it ... just to preserve your ownership of it... LOL
You said you replaced two filters.. I assume you did not clean the filter inside the fuel tank ?
Particularly with you using an exotic blend you need to check that....
Glow plug light can have problems independant of the glowplugs...
When you get it home set the valves..... and run some Diesel PUrge through it according to the instructions on the can...these things will give you a baseline to start from.... be sure to DP full strength.. don't just dump it into the tank... although a second can into the tank is a nice thing after you have cleaned the tank filter....

[jeffl]

i just rolled it down to another street, far from the road crew.. tried starting it again, cranked it for 15 seconds or so, and it sputtered and thought about coming to life, but changed its mind.

i'll check the tank filter. the two that i changed were the main fuel filter and the prefilter. prefilter wasn't clogged at all, but the fuel in both was somewhat dark.

i'll also run some of that Diesel Purge.. will any kind of diesel cleaning additive do the same?

you think the biodiesel could have loosened deposits in the fuel tank in a mere 200 miles, to the point where the fuel tank filter jams up?

tommorow i'm going to get to work on it. anything else i should check?

thank you all,

jeff

[jeffl]

i have to drain, remove and disassemble the whole fuel tank in order to get at that filter that protects the intake line, on the gasket, on the bottom of the tank, right?

Also one thing to check too is:

That the primer pump doesn't leak fuel.
If it pours out of it when your priming then
you might have air entering the system.

Louis.

[kerry]

Before going to all the work of cleaning your tank, just get a small container of fresh diesel or purge and run a line to your fuel pump and see if it runs and starts that way. If it does, it's a clue your tank is the problem.

[P.E.Haiges]

Jeffl,

Remove the rubber hose coming from the fuel tank where it connects to the steel fuel line. If fuel runs out fast, strainer inside tank is OK.

If fuel only drips out slowly, the strainer is plugged, probably with fungus. Let all the fuel drian out of the tank and unscrew the strainer from the tank. Nothing else has to be disassembled from the fuel tank.

If the strainer is coated with a brown, silicone rubber like substance, you have a fungus contamination problem that only a biocide will cure.

Clean the strainer, air gun works best, reinstall strainer, work primer pump ( no need the loosen filter) and try to start engine.

P E H

[jeffl]

the primer pump did indeed leak fuel when pumped, so there is air in the system. there is also a couple small bubbles at the top of the prefilter.. normal, right? would it be enough to repair/replace the primer pump and then just bleed the system again, or is there something more i need to do to clear the air out? i read here that pumping fuel through the system is one solution, but that was for determining the position of leaks in the fuel system, i think. anyhow i'll check the fuel coming out of the tank.

also, i'm not sure why the engine died in the first place. any thoughts?

thank you for the replies!

jeff

[Hatterasguy]

Didn't they update the primer pump for these cars? I would say replace the pump their cheap.

[jeffl]

Originally Posted by mb123mercedes

That the primer pump doesn't leak fuel.
If it pours out of it when your priming then
you might have air entering the system.

Louis.

that did it. new primer pump and started right up. i'm left with an educated guess that the car ran out of fuel, and that the fuel gauge is not working below 1/4 tank. so i'll have a look at that. also on the list is check the injectors and adjust valve clearances. i'll let ya'll know how it turns out.
thanks, l8r,

jeff

[Hatterasguy]

Good, isn't it nice when problems turn out to be cheap and simple. Although it sounds like you worked at it for awhile.

[JimmyL]

Good to hear you got it going. My wagon runs out of fuel at around 1/4 tank on the gauge. Removed and cleaned fuel sending unit, but nothing changed.
I can't believe your car wasn't stolen or vandilized. Most cars on the side of the road end up with bricks or bottles through the windows. Residential streets may be different, though.
JL

[jeffl]

yeah, about as minor a problem as you can have. running out of fuel is a bad thing for diesels, is that right? why is that? does it allow air into the system?

it's is still making the knocking noise, only at idle rpm. also strange is that the prefilter gets a lot of air in it, i mean maybe 1/3 air and 2/3 fuel. when i rev it up, the air gets pushed out. i think there's a leak somewhere in the fuel line around or before the prefilter. could that also be the cause of the knocking at idle?

heck, while i'm at it: something makes a squealing noise when i turn the wheel while moving, more noise to the right, less to the left. none when goin straight. none while standing still and turning the wheel. steering gearbox adjusted too tight, maybe? no, its the left front wheel bearing, i'd wager..

i never guessed how complicated some of these systems are.. but its great to put a dent into learning about it.

jeff

[kerry]

It's normal to have air in the prefilter. Don't worry about it. Yes, running out of fuel does allow air into the system.

[kamil]

here's a stupid question....
Do you have diesel in the canister filter ? I changed mine recently and the car did not want to start until I pumped the hell out of the pump to fill the cansiter with diesel. Just a thought