Hey guys,

Here is a nice long post about my dead car.

What happened:

I finished up my second tank waste vegetable oil install last week. Sadly, I only had 5 gallons of WVO and burned through all of it quickly. I have been running on plain jain diesel for the last three days.

Last night I drove it home from work. Everything was fine. I parked the car on an incline facing up, and went inside for some sweet sleep.

I woke up at 5AM for work, and took off shortly after. It was pretty cold out, mabye 45 deg F. I fired her up after the normal 5-6 seconds of glow the light suggests. I was really late for work, so I only let it warm up for 15 seconds. I threw her in drive and took off. I made it up the rest of the small hill the car was parked on, and about 200' from the house before I noticed a serious lack of power and hesitation. As I acclerated from a stop the car felt slow. I eased up to WOT to find that the car couldn't make it past 1500-2000RPM.

I made it another 50' before the car started missing badly and dropping RPM. I shifted in to neutral, the car died, and I coasted to a stop on the side of the road. It was mabye 45 seconds from start up to dead.

I, of course, tried to start the car again to no avail. After three of four sequences of glow and cranking, something really wierd happened. I cranked it over, and it almost caught. I left off the starter, and the motor seemed to be running, at 0 RPM! For 20 or 30 seconds, the car was doing something. It was certainly not running on all 5 cylinders or idling -- but it was shaking a little tiny bit and was making a strange shrieking noise. I don't know how to explain what happened, it was not the sound a running motor. Thats why I had to touch the valve cover to confirm the noise and shake was coming from the motor!

The car is dead on the side of the road right now.

What I am thinking:

About the wierd running state -- only thing that I could think of was that the starter was stuck on, or the motor was trying to run but dragging the starter ... I don't know. The car has made a wierd shriek right after start up before, but I never thought it was anything but an old starter noise.

Why it died -- it was the classic "running out of fuel" feeling. I encountered this before during my install troubleshooting last week. I had a hard time priming the WVO side of the solenoid, so when I would flip my switch the car would get fed air and die in a similar manner after -- not coincedentely -- about 45 seconds. I fixed the air leak and had no problems switching between fuel tanks seamlessly. The car has not died in over a week.

Three days ago I was cruising around on WVO, started to run out of grease (guage isn't working right), felt the lack of power, and flipped the solenoid off. Diesel kicked in and after 10-15 seconds the car was back to full power. I thought, "Hmmm, that might have gotten a little air in the loop... oh well, it'll work itself out. I need to get more oil!" I didn't think much of it untill my car died today.

This might have something to do with it?

Now, the situation as it stands, and what I have tried:

Stock plumbing is:
diesel tank --> lift pump --> primary filter --> IP

My plumbing is:
tank --> primary filter --> solenoid --> lift pump --> IP

They are functionally the same, except I need to run a closed loop system (no return to tank) so that when I am running WVO, it is not sent back to the diesel tank. I do have a brass valve that allows me to open or close the return so I can get air out of the loop if I need to.

Anyway, I have confirmed that I have diesel flowing through the primary filter and prefilter, through the lift pump, and out the back of the injection pump. No bubbles are coming from the IP during priming. I cracked an injector line and saw no drops after 10 cranks.

However, I turned the thing over for a good 60-90 seconds and got it to ALMOST start running by itself. When turning it over, it feels like it has a little help from the motor keeping it going. I let off the starter, and she ran for a good 4-8 seconds before choking. I don't know what to do. I have confirmed, to the best of my knowledge, that the IP has fuel, but doesn't seem to pump it.

Any tricks to getting this thing started again? Any other methods of confirming the IP has fuel? What was the freaky running state it was in?

Thanks in advance for any information, Cassidy

__________________
Cassidy
1982 MB 300DT - Running Great @ 104K!

1972 MB 220D - RIP @ ~200K (Dropped prechamber)
1992 MB 190E 2.6 - SOLD @ 145K

Have you hand primed the fuel pump.... and then after you do be sure to tighten it again.. so it is not sucking air...

Does your WVO pass through the primary filter?

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Yea, heavily clogged filter w/ solid grease, or
major air leak, or
major air in system, or
solonoid stuck in improper position or lost power to it, or
primer pump open, or
what else....

That running-on thing could be starter, or maybe it was actually running in reverse? (actual dieseling) That has happened to me in a diesel before. Sounded bizzare, no rpm showing, no power...but that was in a stick when I had rolled backwards...

If it were mine, I would consider re-routing the stock hoses as they were originally, and see if she runs ok. Could be major air issues. It would give you some peace of mind to drive her as she ran before.
Did you remove the last blocked injector overflow line to bleed air out of the high point of the injection system? (rear of engine, little braided hose)

I am slightly suspicious of your lift pump as well, but if it were running fine prior, then I would suspect some kind of restiction to flow.
in Monterey area, I would be happy to help look at it, but wont have time till next Fri. I have almost completed my conversion as well. Drop me an email.
And most of all, don't get frusterated! Your car will be fine, and you will later laugh at all this. Hopefully I will be laughing at mine by then too. Man, this is a lot of work...

(wow, I just noticed your car has only 100,000 on it. too early for pump failure...)

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Think Alternative Energy!
300CD '80 (now gone but not forgotten...)

Nope. All filtering of fuels is done before the solenoid because the stock filters are absolutely not setup to flow WVO.


Yes. My arm is exhausted! I must have pumped it 500+ times this afternoon.

Nope! I am gonna try that. Perhaps there is an air lock past the IP?


Okay, it is all becomeing clearer now. When it died, the car's primer pump was not screwed in. This and the hill parking could explain the air leak.

I did not remember the order of events clearly in my mind because it was really damn early, and I was a little panicked.

As the car was coming to a stop, I threw it in reverse on accident while it was still rolling, but after the motor had died. I meant to shift in to neutral, but I pushed to hard. It engaged in reverse for a split second before I pulled it back to neutral. The motor must have started running backwards.

Did I destroy my motor or transmission?

__________________
Cassidy
1982 MB 300DT - Running Great @ 104K!

1972 MB 220D - RIP @ ~200K (Dropped prechamber)
1992 MB 190E 2.6 - SOLD @ 145K

Cazzzidy, I am still not convinced you can make an engine run backwards with an automatic transmission. Even if you did, sure, it's not good for it, don't do it a bunch, but in my opinion, there is no was you should worry about damage.
I think the odds are miniscule...

Remember, that's a Mercedes Diesel your talking about.
Those beasts are tough, seriously tough.

If you left that primer open, you've incorporated lots of air into the system. And that primer isn't going to work the way it was designed, because you've changed the location of the filters. Here is a great link, thank you Guru of Veggy Systems Dieselrover from Neoteric Biofuels, for priming such a veggy system: (scroll down)
http://biodiesel.infopop.cc/eve/ubb.x?a=tpc&s=447609751&f=159605551&m=864101181&r=864101181#864101181

__________________
Think Alternative Energy!
300CD '80 (now gone but not forgotten...)

Hey, let us know how it is coming along.
I still think you should put the hoses back to their stock configuration, and will be pleasantly surprised that she runs fine.

__________________
Think Alternative Energy!
300CD '80 (now gone but not forgotten...)

It sounds like classic clogged fuel filter to me.

__________________
Michael LaFleur

'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
'85 300SD - 150,000 miles (sold)
'89 190D - 120,000 miles (sold)
'85 300SD - 317,000 miles (sold)
'98 ML320 - 270,000 miles (sold)
'75 300D - 170,000 miles (sold)
'83 Harley Davidson FLTC (Broken again) :-(
'61 Plymouth Valiant - 60k mikes
2004 Papillon (Oliver)
2005 Tzitzu (Griffon)
2009 Welsh Corgi (Buba)

Yea,
I guess it is always easy to assume the filters have been changed first thing. And that the fuel tank is not empty...
The simple stuff that is so simple to forget...

__________________
Think Alternative Energy!
300CD '80 (now gone but not forgotten...)

The only new part I have bought for my car so far is the upgrade primer pump. It will be changed on every Mercedes diesel I touch from here on out. Best $20 I have spent in a while.

Pumps push quite well, they do not pull very well at all. If you have any restriction or leaks in the fuel supply to the lift pump, you no go.

I am sorry you are having problems, but I am glad you shared them. Too much of what I read about alternative fuels seem to be painted with a rose colored brush by people with rose colored glasses. I feel like I am having sunshine forced into unnatural places.