1980 300D sat for a year, won't start - PeachParts Mercedes-Benz Forum

CommieGIR · #1 07-04-2011, 12:40 AM

Hello All!

While I'm new to your forums, this isn't my first diesel, although I'm used to Volkswagen TDIs and IDIs. Bought my first Mercedes 2 weeks ago, an abused but excellent condition 300D Station Wagon with the OM617 3 litre engine.

Well I got it home on a trailer, but cannot get it to fire. It had biodiesel run through it, then he left it sitting for a year, and now that I have it, it will not start, cranks strong, and occasionally I'll hear it cough but it will not start.

I've shot the glow plugs, though I found shooting them odd (was seeing 12 volts even with the key off, but if I turned the key to start, the voltage at the fuse to the glow plugs dropped to zero), changed the oil with fresh synthetic 5w40 diesel oil, new oil filter, new fuel filters, and new air filter.

Still just cranks, never starts, I've bled the fuel system, and am actually running it off a jug of diesel because of the old veggie oil in the tank.

I'm out of ideas, anybody got some help for me?

Engine has 226k miles on it.

leathermang · #2 07-04-2011, 12:53 AM

checked the injectors ?

Aquaticedge · #3 07-04-2011, 12:54 AM

air in the lines. Keep cranking.... your 300D is a 300TD make sure the IP is moving fuel, chances are the veggie oil in the tank has congealed the innards of the pump. Crack the nut on the hardlines on the injector and see if fuel comes out.

CommieGIR · #4 07-04-2011, 01:03 AM

Quote:

Originally Posted by Aquaticedge

air in the lines. Keep cranking.... your 300D is a 300TD make sure the IP is moving fuel, chances are the veggie oil in the tank has congealed the innards of the pump. Crack the nut on the hardlines on the injector and see if fuel comes out.

How is it a TD if it is lacking the Turbocharger?

Also, I've manually bled with the pump on the IP, fuel flows freely, a slight air bubble but nothing horrible.

I am tempted to pull the injectors, because I suspect they are gummed up. Whoever tried to run veggie in this thing ran it straight, without an ounce of filtering (the pre-filter has small bits in it, like oil from a taco deep frier)

I've read several threads, some point to glow plugs (they are now new) some point to the fuel pump that is attached to the side of the IP. I've never had this many problems with getting a diesel started, guess the VWs are just easier!

When I am pumping the manual primer, I hear a squeek coming from the fuel line on the engine side of the IP, from the banjo bolt that goes to the filter

BoiseBenz · #5 07-04-2011, 01:10 AM

"biodiesel" and veggie wvo are not the same thing.

Something's wrong with your glow circuit. Pull the fuse out and hold it in your hand.

Try to pull start it. that will purge the old fuel, so you can work on just the glows.

CommieGIR · #6 07-04-2011, 01:14 AM

Quote:

Originally Posted by BoiseBenz

"biodiesel" and veggie wvo are not the same thing.

Something's wrong with your glow circuit. Pull the fuse out and hold it in your hand.

Try to pull start it. that will purge the old fuel, so you can work on just the glows.

Can't pull start it, its automatic.

Its veggie oil, forgive me.

Quote:

Originally Posted by BoiseBenz

"biodiesel" and veggie wvo are not the same thing.

Something's wrong with your glow circuit. Pull the fuse out and hold it in your hand.

Try to pull start it. that will purge the old fuel, so you can work on just the glows.

Yeah, I suspected the glow plugs, the engine TRIES to start, and I see smoke coming out of the engine intake. I am lacking what I need for a compression test. the engine will cough and I'll hear a cylinder fire off briefly

layback40 · #7 07-04-2011, 01:24 AM

Welcome to the forum!!!
We all hope you get all the help you need !!

Quote:

Originally Posted by BoiseBenz

"biodiesel" and veggie wvo are not the same thing.

Something's wrong with your glow circuit. Pull the fuse out and hold it in your hand.

Try to pull start it. that will purge the old fuel, so you can work on just the glows.

Good advice!!

You may have a case of "Death in a jug"
Interesting that it cranks strong, maybe low compression from stuck rings caused by WVO use?
Why was the car sitting for a year?

The idea of pull starting has merit if you can. Best done at about 40 mph. Get up to speed in neutral & then put into D. The trans will turn the motor much faster than a starter. Once started it probably wont idle properly for a while.
Good Luck !!!!

CommieGIR · #8 07-04-2011, 01:34 AM

Quote:

Originally Posted by layback40

Welcome to the forum!!!
We all hope you get all the help you need !!

Good advice!!

You may have a case of "Death in a jug"
Interesting that it cranks strong, maybe low compression from stuck rings caused by WVO use?
Why was the car sitting for a year?

The idea of pull starting has merit if you can. Best done at about 40 mph. Get up to speed in neutral & then put into D. The trans will turn the motor much faster than a starter. Once started it probably wont idle properly for a while.
Good Luck !!!!

Interesting, I'll give it a shot! There isn't any repercussions to the transmission or torque converter by pull starting is there?

Yeah, according to the owner (who I don't really suspect would lie to me) it ran when parked, sat till I bought it because he decided he did not want to work on it anymore.

It came with a spare injection pump, but I'm hoping its not the issue.

Either way, I got the whole thing for $500

And I do trust you on the TD thing, It is just new to me to use it like that, but there is a first time for everything!

How can I go about running the glow plugs manually to see if that is truly the issue? I ohm'ed them out to the engine body, good conductivity...

Aquaticedge · #9 07-04-2011, 01:21 AM

Technically TDT

Touring Diesel Turbo

leathermang · #10 07-04-2011, 01:22 AM

TD stands for ' Touring Sedan ' I believe...
anyway... 300 TD is a Station Wagon in English...
trust us on this one....
They made the both with and without turbo engines....
both are TD....

Aquaticedge · #11 07-04-2011, 02:57 AM

You can bypass the relay, not sure how. might be worth pulling the old ones out and putting new in. Also would be worth checking the relay. you should hear an audible click when It shuts off I believe (after the glow cycle)

GregMN · #12 07-04-2011, 11:12 AM

I wrote this up and then went back to re-read your original post. I found that you have already bled the fuel system and isolated the fuel supply. You still need to confirm that each glow plug is working. The next thing is doing a compression test. I will just go ahead an post what I wrote and you will ignore what is redundant to your original post.

______________________________________________________________

People generally do not stop driving cars because they run too good. There is a reason it was parked. Evey time I buy a used car I eventually find out why the previous owner sold it. On my wife's W210 it was a $2 o-ring that caused random no-start conditions.

Running unheated VO in a single tank fuel system will shorten the life of the engine by quite a bit. VO needs to be above 160 degrees for the injectors to spray it correctly. Cold VO will dribble out and not burn completely. The unburnt VO will get on the cylinder walls in into the piston rings. The rings will become impacted in their grooves ( you need a chisel to get them out) and will not seal the piston in the cylinder. You now have low compression and VO leaking past the piston to the crankcase. It will also deposit carbon on the glow plugs causing them to burn out prematurely and making them hard to remove.

Leaving VO sit for a year can lead to polymerization. The VO will turn to a plastic. This requires air, so it is possible that this did not happen in the lines and injector system, but there is most likely an issue inside the fuel tank where there was air.

If it is not a rusty POS, $500 is a good deal for a W123 wagon. You can afford to spend a little time and a little money to revive it.

Put a charger on your battery and/or get a new battery.

Change the fuel filter.
Get a small container of new, clean, diesel.
Put your fuel source and return lines in the container so you have isolated the engine from what may be coming from the tank.
Crack the fuel line fitting at the IP and use the hand primer pump to push the clean fuel to that point. Once you do, tighten that fitting.
Crack the lines at all the injectors, crank the engine and see if you get fuel flow at the injectors.
If you do get fuel flow try to pump until you know that all the fuel in the injection system is diesel not VO.

Pull the glow plugs and test them. Hold them in a vise grips and power them up. The tip will get to 1200 degrees so be careful with them.
Ideally you would ream out the holes before you reinstalled them, but you probably do not have that tool on hand. You will want to do this as soon as you can get that tool. It's maybe $25 online.
Now all the glow plugs either worked or were replaced with new ones.
Check for power out of the relay. If no power out of the relay, jump power to the glow plugs

Now you have fuel and glow plugs. You also need compression, but you do not have a compression tester on hand, so just try to start it.

kerry · #13 07-04-2011, 10:37 AM

If you are getting 0 volts to the glowplugs in the start position, something is wrong. To manually heat the glowplugs, remove the glowplug harness plug from the relay, twist together 5 pieces of solid copper wire, putting the 5 ends in the plug harness connector, then run a heavy jumper wire from the positive post on the battery to the 5 twisted together wires. This will energize the plugs.

Yak · #14 07-04-2011, 01:45 PM

Quote:

Originally Posted by CommieGIR

Hello All!

While I'm new to your forums, this isn't my first diesel, although I'm used to Volkswagen TDIs and IDIs. Bought my first Mercedes 2 weeks ago, an abused but excellent condition 300D Station Wagon with the OM617 3 litre engine.

Well I got it home on a trailer, but cannot get it to fire. It had biodiesel run through it, then he left it sitting for a year, and now that I have it, it will not start, cranks strong, and occasionally I'll hear it cough but it will not start.

I've shot the glow plugs, though I found shooting them odd (was seeing 12 volts even with the key off, but if I turned the key to start, the voltage at the fuse to the glow plugs dropped to zero), changed the oil with fresh synthetic 5w40 diesel oil, new oil filter, new fuel filters, and new air filter.

Still just cranks, never starts, I've bled the fuel system, and am actually running it off a jug of diesel because of the old veggie oil in the tank.

I'm out of ideas, anybody got some help for me?

Engine has 226k miles on it.

A few questions and maybe a suggestion:

Did it run on biodiesel or WVO? Bio has a less bad reputation than WVO for gunking up an engine and fuel system. Old bio vs. old WVO in the tank will probably also have significant differences.

The voltages at the GP relay or fuse sound wrong. Do you get the normal light cycle for the GP light? If the relay's working correctly it should glow, then go out in less than around 30 seconds, then you should be able to hear a "click" when the relay shuts off, maybe around 45-ish seconds.

The 123's have a history of failing ignition switches over time. It could be possible you've got an internal switch failure that's engaging the starter but maybe not providing power to the GP relay. Not a high probability but if you're getting strange voltage readings it may be worth considering.

Double check the fusible link for the GP relay to make sure it's not cracked or loose.

CommieGIR · #15 07-04-2011, 02:21 PM

Quote:

Originally Posted by Yak

A few questions and maybe a suggestion:

Did it run on biodiesel or WVO? Bio has a less bad reputation than WVO for gunking up an engine and fuel system. Old bio vs. old WVO in the tank will probably also have significant differences.

The voltages at the GP relay or fuse sound wrong. Do you get the normal light cycle for the GP light? If the relay's working correctly it should glow, then go out in less than around 30 seconds, then you should be able to hear a "click" when the relay shuts off, maybe around 45-ish seconds.

The 123's have a history of failing ignition switches over time. It could be possible you've got an internal switch failure that's engaging the starter but maybe not providing power to the GP relay. Not a high probability but if you're getting strange voltage readings it may be worth considering.

Double check the fusible link for the GP relay to make sure it's not cracked or loose.

I'm not sure what he ran, from the smell I would say biodiesel, but from the crap the pre-filter is picking up it looks like someone dumped WVO in the tank too (it looks like scraps from a deep frier).

The glow plug light only cycles for MAYBE 5 seconds, and I can't hear the relay, but I can pull the GP relay and the GP light will begin flashing.

I am tempted to pull the IP and replace it with the spare, I get fuel at the injectors, but it wasn't spraying, just kind of pooling out of the cracked injector lines.

So, perhaps the IP got toasted by WVO?

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