'82 300SD Fuel Delivery Problems.... - PeachParts Mercedes-Benz Forum

clunketyclunker · #1 08-30-2006, 11:26 PM

Edit: Chased problem further; still fuel-starved but that's not all keeping it from starting...

Howdy guys (and gals)!
First, THANK YOU to everyone who posts on this forum. This is my 1st post, but I've already learned tons from your hours of unpaid posting.

To cut to the chase:
I have an '82 300SD (blue, grey interior) with the 5-cyl turbo. The car was given to me by a guy who used it as a daily driver until he started to experience what I believe to be the infamous "k2 piston problem," after which he let the car sit for 3 years.

I have it now and have yet to get it to start.

The glow plugs and relay are good. The car has all new filters and oil. The diesel was 100% drained and replaced with fresh fuel.

My question lies with the injector pump - I've bled the system as best as I know how, BUT:

When you crank the engine and loosen a nut on the fuel lines at the injectors (or at the pump for that matter), fuel will spurt out as the engine turns on all but one of the lines (the 2nd from the steering wheel, if it matters.) Does this mean I haven't bled enough air or that there is a problem with my injector pump?

Thanks in advance, and apologies to everyone if this topic has already been covered.

bgkast · #2 08-31-2006, 12:30 AM

How long did you crank it?

What is the "k2 piston problem"?

clunketyclunker · #3 08-31-2006, 02:06 PM

Got my B's and K's mixed up. Meant to say "B2" piston problem - http://articles.mbz.org/transmission/b2/repair/

Slipping out of 1st if under heavy load.

I cranked it about 20 seconds at a time, waited a couple mins, tried again. (repeated about 8 times or so)

Fuel would dribble as the engine spun as soon as i started cranking on all but one of the lines (at either end).

The car would occasionally "put" as if one cyl had fired, but never any more than that.

Thanks!

barry123400 · #4 09-03-2006, 11:00 AM

Try spraying a little wd40 into the intake after removing the air cleaner top. It might just start up or at least give you an indication. Also ask the last owner how the engine was just when he stopped driving it. Also rather than trying this or that I would do a compression check if the wd40 did not let it run a little. It has been mentioned some examples of 123s sitting a long time might require a tow for the first start. Have a good look in the archives. It should still run on five cylinders but the sixth may activate once running.

pwogaman · #5 09-03-2006, 01:01 PM

You might also want to check the tank strainer:

http://www.peachparts.com/shopforum/showthread.php?t=124027

jwhughes3 · #6 09-03-2006, 01:17 PM

Quote:

Originally Posted by barry123400

It should still run on five cylinders but the sixth may activate once running.

I've been having trouble getting that 6th cylinder in my 83 300D to activate since I've had it...

All good suggestions - I vote to try the WD-40 or try hooking up a small bottle of diesel to where the primary filter feeds in similar to when you are purging to eliminate the tank strainer as a culprit. Fungus could have been growing in the tank while it was sitting all that time and blocked the strainer - not completely as you are getting some flow, but maybe enough to keep it from running.

John

barry123400 · #7 09-03-2006, 04:03 PM

I do not know how I forgot the number of cylinders?

At least you seem to have located the mythical sixth one on a 617. Even if you cannot get it to fire.

clunketyclunker · #8 09-22-2006, 01:04 AM

Quote:

Originally Posted by jwhughes3

where the primary filter feeds in similar to when you are purging to eliminate the tank strainer as a culprit.

Did some more diagnostics - forgot to try WD40, but will tomorrow...

I grabbed an electric fuel pump and bypassed the mechanical fuel pump - I put the electric pump sucking from the tank line and spitting directly into the main fuel filter input (fuel filter is brand new).

Pretty high volume of diesel flowing back to the tank through the return line when the pump is on. I KNOW injector pump is getting LOTS of diesel...

Glow plugs get hot, starter turns the motor at (what I guess is) a pretty good speed, some blowby smoke but no pressure, lots of air puffs out of the tailpipe, no ignition.

Oddly, it seems like the IP isn't putting out much volume of fuel to the injectors - with the lines removed it shoots fuel about 1 foot in the air on everything but #4, but it seems like it takes an inordinate amount of cranking to get fuel through the lines...

Could the injectors clogged? Is there a "good" solution to soak them in for a first try at cleaning?

I'll try the WD-40 thing tomorrow and let ya'll know how it works out.

THANKS for the help so far (and for setting me straight on the 6th cyl!!)

clunketyclunker · #9 09-22-2006, 07:37 PM

WD-40 no go, I'd start the spray into the intake as I started grinding, burts of WD-40 about every other second, car did exactly what it was doing without the WD-40.

I plan to go buy a compression tester tomorrow.

What is involved in a tow start? I haven't really found a how-to on the forums, just several reports that "it worked for me".

Just keep the tow rope taught, accelerate to 35 and drop the benz into S? Sounds like the easiest way ever to slaughter my transmission.

Would a tow start work for a vehicle that slips out of 1st?

Thanks for your help!

rocketman93116 · #10 09-23-2006, 12:48 AM

Quote:

Originally Posted by clunketyclunker

Howdy guys (and gals)!
First, THANK YOU to everyone who posts on this forum. This is my 1st post, but I've already learned tons from your hours of unpaid posting.

To cut to the chase:
I have an '82 300SD (blue, grey interior) with the 5-cyl turbo. The car was given to me by a guy who used it as a daily driver until he started to experience what I believe to be the infamous "k2 piston problem," after which he let the car sit for 3 years.

I have it now and have yet to get it to start.

The glow plugs and relay are good. The car has all new filters and oil. The diesel was 100% drained and replaced with fresh fuel.

My question lies with the injector pump - I've bled the system as best as I know how, BUT:

When you crank the engine and loosen a nut on the fuel lines at the injectors (or at the pump for that matter), fuel will spurt out as the engine turns on all but one of the lines (the 2nd from the steering wheel, if it matters.) Does this mean I haven't bled enough air or that there is a problem with my injector pump?

Thanks in advance, and apologies to everyone if this topic has already been covered.

What are the SYMPTOMS of a faulty B2 piston??

clunketyclunker · #11 09-23-2006, 09:01 PM

Quote:

Originally Posted by rocketman93116

What are the SYMPTOMS of a faulty B2 piston??

Slips out of 1st when under load,
Flaring going into 2nd,
3/4 work fine, as does reverse.

Source: http://articles.mbz.org/transmission/b2/why/

These symptoms are *exactly* what the guy who gave me the car was complaining about - why he mothballed it in the first place. Now 3 years later I want to ressurect it.

clunketyclunker · #12 09-23-2006, 09:04 PM

Got my grubby little hands on a diesel compression checker - will try to test compression tomorrow. One question, though: The compression tester I bought (harbor freight POS) screws into the injector hole. Do I have to replace the heat shield after checking the compression?

I read on Diesel Giant's page that every time the injectors are removed the wee heat sheilds must be replaced, I'm not thinking he has any reason to lie...

clunketyclunker · #13 09-24-2006, 10:31 PM

Compression test results are in, and they're NOT encouraging...
Numbering cyl "1" as "closest to front bumper":
1 - 14 bar
2 - 12 bar
3 - 12 bar
4 - 8 bar
5 - 12 bar

Yuck! Aren't they supposed to be 20 bar +-?

Further, injector nozzles look horrible. Grimy carbon crap all over the tips on 5, 3, and 1. The heat sheild on the #5 injector no longer had a hole that went into the preburn chamber - just a 1/16" thick film of crap.

#4 and #2 actually were pretty clean, the heat shield even had some spots where it was still a shiny brass color.

I cleaned out all the poop, removed the heat shields, and hand-threaded the injectors back in place - will order new heat shields and valve cover seal tonight.

I'm thinking I'll follow Diesel Giants' recipie for tearing apart and cleaning the injectors, as well as a valve adjustment.

Are compression numbers that woefully low indcitative of something besides valves way way out of adjustment? The car did run quite well only 4 years ago!

Pics will follow.

Thanks

clunketyclunker · #14 09-24-2006, 11:38 PM

Yuck! I guess all that grinding I did made it nasty! Seems like this would have to have been something that was going on while the car was being driven, tho...

Thoughts, anyone?

clunketyclunker · #15 09-24-2006, 11:39 PM

And then the nozzle: