300D No start, only with gas held to floor, no power
 

Hi,


I'm having trouble with my 300D 1984 om617 in Philadelphia. I have been running it on Centrifuged WVO for about a year. Yes I won't be doing that anymore, I'm buying a bio diesel processor



Anyways-



The car ran just fine and about a month ago I went to fill up with regular Diesel. From that point forward the car kept loosing power. I would say withing a 3 day time span.



I replaced the fuel filters and it ran a little better but not much. I switched the suction and return lines. It didn't run any different. I rebuild the lift pump and installed a new primer pump (Bosch). That didn't do anything.


I installed new Monarch injector nozzles and don't have a pop tester, but it quieted the engine down, less clackety but didn't improve power. I did find 4 of 5 (old) nozzles were just about seized. And I will be pop testing new nozzles. I just received shims in mail in case they do need adjustment.


Lets see I bought a new injection pump and didn't want to mess with timing. I removed delivery valves from car and found them pretty clean. I installed delivery valves from other IP and used new crush washers. The delivery valves didn't improve issues.


I did pull one element from IP in car and used a dial caliper to mark position to 100 thousands. It was clean and fine.


The compression was checked (After a valve adjustment) -
1 - 405

2 - 395

3 - 340

4 - 390

5 - 340


Is there anything wrong with compression? Why it doesn't run right.


I saw forums online that show caked up rings and I decided to remove head and check pistons. Last night I pulled #2 piston to check. Its almost perfect. I can still see machine marks on cylinder wall and the piston had very minimal carbon buildup.


Two of the pre-chambers on head # 5 and # 3 had some caking on them. And I think #3 had one plugged up hold.


Otherwise this is where I'm at. I don't really want to tear down the engine anymore, if I don't have to.



Everything I have done, has been from hours of research and hasn't yielded a solution. The only remaining solution would be to replace IP. Maybe the elements started wearing out?


Any other thoughts?

For diesel engines in general.:

When the injector pump is in the start position and engine stopped, the fuel rack should be a full fuel. Having to push the throttle to start tells me that the rack is sticking.

Running real diesel after running glop fuel probably cut loose stagnant glop. As a side note, don't run motor lube oil / ATF as these are not designed to be burnt. If anything 2 stroke oil in the fuel could be of some benefit as a pump lube.

Define " bought a new injection pump " 100% new / rebuilt / used ? Taking apart the first two isn't a good idea when trying to fix a suspected bad pump.

Don't randomly take things apart without diagnosis. I don't know this engine specifically but the compression numbers look good enough the engine should start and run without difficulty.

Also, when chasing a suspected compression leak, always do a cylinder leak down as this tells you where the air is leaking out. While not a problem in your case, a cylinder leak down is the _ONLY_ reliable way to find a compression to coolant system leak.

How about linkage slop? Later style w123 “throttle” linkages are notorious for falling apart right at the firewall.

You burn waste oil you start by cleaning out the fuel system when problems arise.


The head removal was a waste other than perhaps checking things. The compression numbers where good to run on. They may or may not be improved for consistency with a cylinder soak down. Where the piston rings loose in the piston you pulled?


You could have a lot of fats accumulated in the injection pump for example. What I would do is fill the injection pump with laquer thinner. Let it soak for a couple of days.


Remove the relief valve and pump the thinner out watching what is coming out. If it is bad do it again. Just hook a line to the input of the lift pump and pump the thinner in .


It is too bad the head is off. It stopped the chance of checking for too much air in the fuel. Perhaps it is best to install the head and go from there first.

You did check for growth from the vegetable oil in the vent line from the fuel tank? By leaving the fill cap loose. I had one that sat for a year It still seemed to be retaining some. It is not your problem but is just one thing you check. Plus you never leave a car on vegetable oil sitting around. It turns to a type of glue. Perhaps the centrifuge eliminates the components that enable this.

There is a small chance the elements in the injection pump are over tolerance as well. Overall it can be a considerable issue. To get to the point of establishing that is a possibility. Since you burnt Waste vegetable oil. Put a container of vegetable oil feeding into the lift pump. If it will run on this it narrows things down.

There is in interesting point here. If the fuel pressure relief/overflow valve is gunked up it won't hold fuel supply pressure inside of the Fuel Injection Pump.
could be the same if the spring is compressed too much.

300D 1984 om617; is this a turbo diesel or a non-turboed Euro 300D? I am asking this because they have different models of Fuel Injection Pumps.

Please explain what you used the dial indicator before or after you removed the Element. Or perhaps you are using the wrong terminology and it was not an Element you removed.

My 300D 1984 with turbo has a MW type Fuel Injection Pump and if you pull out the element it mess with the Fuel adjustment on that element. Loosening the 13mm nuts (if you have not done that don't do it) and twisting the element changes the amount of fuel it puts out.

Try getting one of those 1 liter spare fuel cans or an old type gallon paint thinner can full of diesel Fuel put it under the hood between the back of the Head light and the front of the fender well (you might need to remove the Window Washer tank).

Run a separate hose from that to the plastic filter and get on the hand primer and pump until the air is out of the system and start it and go for a drive. That bypasses the fuel lines all the way back to the fuel tank fuel tank screen and any issues with your fuel tank vent. If things improve you know you have a problem from the fender well back to and including the fuel tank.

This is a picture of part of a Frantz Toilet Paper Filter that someone apparently used to filter WVO with. Notice the plastic like film.

Hi,

Thanks for all of the responses,. I will answer them back as I get time throughout the day.

Does anyone have the torque spec for head bolts? All I could find is the torque sequence.

Have you cleaned the screen in the fuel tank? Compression readings should be within 10% of each other.

Hi,

Thanks for all of the responses,. I will answer them back as I get time throughout the day.

Does anyone have the torque spec for head bolts? All I could find is the torque sequence.


Diesel911 -. Thanks for the response. I will run some paint thinner through the pump with the primer pump. Hopefully it's just something sticking. The car took about 30 seconds to get any power with the foot to the floor.

I couldn't find any illustrations onpine showing what part of the IP could be sticking. When I removed the element, the rack seemed to be moving just fine and turning the way it should.

Although once warmed up, it took alot longer to get any power to the car.

If the rack is stuck, why wouldnt the car idle properly?

It's a turbo 300D

I used a dial caliper to measure the element spacing prior to removal.

https://ibb.co/JqTFxz4


barry12345 - piston rings weren't loose. The relief valve on IP was checked and spring adjusted. Was clean. I will run thinner through the IP and flush IP.

Didn't see any growth in tank. When you say Elements in IP could be over tolerance what do you mean? Dirt and crud is stuck between them?

Phillytwotank -. Linkage was tight. I ran car from injector pump and moved linkage by hand no change.



97 SL320 -. Thanks for the message. Rack is most likely sticking. Thank you!

The spare injection pump is used/known good pump.

Leakdown test. I'll definitely do that when I need to test engine.

Hopefully this IP can be cleaned enough. I'm not looking forward to replacing IP. Can delivery valve be removed from #1 and a dial caliper used to time pump to motor? I've seen it done that way on Cummins p pumps.

I don't however it wold be a really good idea to have the hear checked for flatness and have the valves ground while it is off.

There is a very small chance the injection pump elements are worn. WVO can do this. At the same time there are quite a few other possibilities.

I am more along this line, saw no mention of "Viton" lines used before the switch to WVO. From my understanding it swells regular diesel lines restricting fuel flow or just turn to mush before leaking.

Yes I forgot the mention, viton lines are installed.

Poorly processed WVO will quickly gum everything up in the IP and can score the pumping elements. When running WVO, it isn't that bad because the viscosity is higher and its own varnish helps clog up scoring and loose tolerances. Introduce pump diesel, especially with some bio content, and it will go to work dissolving the leftover crap from the WVO. If you have scored pumping elements, or if you have increased tolerances due to wear from WVO, you now have the inability to pump diesel to a high enough pressure to pop the injectors and the fuel rack can stick and bind from the varnish left behind. Swap the IP, don't waste your time trying to fix it further, it's just good time/money thrown after bad.

Typical issues with using wvo might be better sourced in the alternative fuel section. Most members on this portion of the site are not really fans of using it.

There are a few users that seem to get away with using it longer term. Yet I believe they are in the smaller minority.

I would be a fan of cheaper fuel but over time on average. I do not think WVO qualifies as this. The usage of it seems to be dying out as well. In a way it is too bad that it did not work out for so many.

I have tried to keep an open mind about this. Certain bio diesel fuels depending on their bases seem to be okay. Not all though as we had so many issues locally with the locally sold bio diesel. It was withdrawn from the market. I do not know since the company selling it was very large. If they paid for all the damages it created. It was rumored the base was fish oils. My comment at the time was perhaps they did not get all the bones out.

A person transiting this area had his 1984 300d quit on the highway. He was using new vegatable oil. It was his bad luck that he had it flatbedded to a local normally very competent shop.

They had been changing out so many injection pumps on the cars using the local bio diesel and his starter had failed with too much cranking. They told him a replacement starter was needed and possibly a new injection pump.

He left the car at the garage and purchased a new one to continue the trip. I saw it siting there for some time. The garage owner and myself eventually settled at 500.00 American. It took months to secure an ownership by the garage through the court.

I then had it flatbedded home. The wire from the solenoid to the starter had burn up. I replaced it with a strip of stainless steel with two holes drilled in it. I then drained the tank but it stopped draining. The real problem was the vegetable oil had grown or developed a solid blockage in the fuel tanks vent line. The lift pump could not overcome the vacuum when it accumulated enough.

The only reason I purchased it was it seemed a genuine clean low milage example. When I purchased it no matter what it took engine wise there were good injection pumps and engines available cheap locally at the time if needed. This is not the case here now in this region anyways.

It only luckily took me a couple of hours and under two dollars in parts to have it running well again .

The only other mechanical need of that car was I think I heard a rear wheel bearing periodically. I just have not driven it enough to be certain of that. It was just his misfortune to have it stop running near the area where so many issues where caused by the local bio fuel at the time. This was just an example of what burning vegetable oil cost him.

Your compression results can be some of the rings are partially sticking. The compression results posted are not typical of these engines. This is easy to deal with when you get the engine running again. A really good ring soaking and some solvent added to the oil and fuel.

The vegetable oil that does not combust gets on the cylinder bores. It gets deposited into the ring lands and turns to a glue initially. It seems with enough accumulation and time it turns to hard carbon and scores the bores of the cylinders.

There is really nothing free in life. So you can pay now or pay later. A few of us older guys on site know how to squeeze a dollar. Hopefully just a habit acquired in the past that is not really required by us now.

I cannot speak for others but for me old habits die hard.. In my mind used vegetable oil as fuel is probably not a reasonable risk/reward scenario. That I have some bias component. Has to be a given. At the same time these are just my opinions.

And burn regular diesel not glop fuel . . . .

Well the car is coming back together and I ran laquer thinner through IP.


<a href="https://ibb.co/k58XF8r"><img src="https://i.ibb.co/sbwqrwD/IMG-20190809-065334686.jpg" alt="IMG-20190809-065334686" border="0"></a>


The laquer thinner expanded my brand new primer pumps seals and I think it's just about shot. But the rack seems to be moving freely. Hopefully tomorrow I can get it going.

Good luck! And do brew bio, it's the best way to run recycled WVO through these engines. NONE of the issues that straight has, and mixes easily with D2. Also, it cleans internal parts, not gums them.

Allowed time for the soak I hope. Just in and out does not have enough time to break down fats. You of course follow this by pumping in diesel fuel. Gas engines run well on the thinner but not diesels I suspect.

IME, regular lines are fine with WVO. It's biodiesel that turns them to mush, I'm told.

The Mercedes is back together. I wanted to try old pump after it had been cleaned out. No luck, still runs the same. Yes I let it soak overnight and the rack linkage fully moves. I can see it under the ADLA.



I have to swap to my other IP. Can I line up TDC, pull pump, align new pump to same marks and install?

The "rack" is internal to the IP. Looking at the lever on the side of the IP tells you nothing. That lever just acts on a spring mechanism inside the IP to set the governor tension. The rack is controlled by the centrifugal governor. Unless you've taken the covers off the IP and inspected the internals, you have no idea if the rack is actually freed up and moving, the springs are quite weak and it takes very little to bind that mechanism up, everything is an extremely precise fit, it has to be.

Time for a new IP. Once they get gummed up, they rarely come back without a full tear down and rebuild with replacement parts.

This expense is something the WVO / BIO / old motor oil people seem to ignore.

I'll second the idea of installing a good injection pump. My understanding is that Bosch service centers will not accept as a core an injection pump which has been used with VO / WVO because the damage is too severe and not economical to repair.

Alright, injection pump is installed. I took alot of time researching timing and decided to go to with the 15 ATDC method. The slot in view port was perfectly centered. I placed crankshaft at 15 ATDC and lined up Pump, with slot/view port held in place. I used a mirror to ensure slot was centered.



For some reason, after many attempts I can only seem to get the pump to time in at 10 ATDC or 20 ATDC. I ran the car at 10 ATDC and it didn't want to idle very well. At 20 ATDC it runs much better and I will post a video tomorrow.



The problem is that I can't seem to acheive 15 ATDC. Maybe I'm missing something. Does the coupling (between pump and gear) have to be adjusted to allow a 5 degree decrease in timing?


Otherwise, the video will show some idling up and down at lower RPM's and the engine seems to smoke a little at idle, and more at higher RPM. I know the Injectors still have to be pop tested. Could anything be causing idling issue, or smoking from exhaust?


I don't want to adjust idle screw too much.


While taking a test drive, the car didn't want to shift to next gear easily (automatic) and I had to let off pedal to get it to shift. Which is an indication of transmission downshift not adjusted properly. I know the car shifted fine, prior to pump change and don't want to adjust downshift cable if another problem may exist.

Once it's installed, you turn the whole pump in it's socket, like a distributor to adjust the timing.

moon161 Once it's installed, you turn the whole pump in it's socket, like a distributor to adjust the timing.


I adjusted pump and timing is right at 15 ATDC.

The car is still running smokey. I drove it up and down the street and started to loose power/died. I'm dropping the strainer in tank and checking for clogs. I think there is a fuek restriction somewhere.

You tried the bottle of diesel or diesel purge? Just take the supply and return lines off the hard lines and stick them in a bottle of diesel or diesel purge and drive it to see if it runs OK. If it does, then your problem is in the hard lines or the tank.

In context, good for a laugh [Kent recommends burn a gallon of VO and then (of course) run a diesel purge]:
https://www.youtube.com/watch?v=cyXz7KaXfao

Since the last post:

I double checked timing of timing chain. It's dead on. Mark with Cam aligns to zero on crank.

No timing chain stretch.

I double checked injection pump timing. It's perfect. 15 ATDC on the sight port.

The injectors were just pop tested. They all checked at 1840 and I adjusted to 1960.

Spray pattern is good. They're new monarchs and it's quieted the engine down.

The two main problems are smoke, including on idle.

Also the idle screw had to be turned all the way in to idle the car.

I already replaced the fuel filters and verified good flow from tank.

Tomorrow I'll verify that my valve adjustment was good and double check compression, if it comes down to that.

Any thought on smoke and having idle screw turned all the way in?

This motor has the emergency shut off throttle blade in the intake correct? I'm thinking the flap is staying partly shut.

Have you checked the entire air inlet system for major restrictions?

Have you made sure the pump shut off system isn't staying partly engaged?

I checked for an emergency shut off on the throttle. There is none.


The air inlet doesn't have any air restrictions


The Injection Pump rack was checked under the ALDA. It moves freely and the vacuum shut off valve isn't stuck.


I ran the car directly off a clean bottle of diesel, to double check the rear tank filter. The car ran the same. Smokey.


The only two other thoughts are to check the valve adjustment and double check compression.



The compression was fine, prior to taking off head and still ran smokey.


The car also takes about 10-15 seconds to start with throttle held down to start. Almost as if it lost its prime.

Maybe the replacement IP was installed out of phase.
Surprisingly these engines can run, albeit poorly, when the IP is timed to the wrong compression event (exhaust instead of intake).

Probably worth a quick check because of the long delay in startup. Plus the smoking.

With the tang in the injection pump visable. The cam lobes of the first cylinder must be pointing generally upward.

You would be far from the first person to have the injection pump timed on the wrong stroke of the cycles.

Why did I suspect this? You had the head off.

Injection pump was out of phase.


I didn't think the car would even run, with it being so far out of time.


It runs much better now, minimal smoke and engine sounds like it has a slight miss. I'll have to look into that at another time.


For the time being, I need to Troubleshoot the transmission shifting/vacuum and engine shutoff with vacuum.


Thanks for all your help

It is a pretty long shot. There is a very remote possibility that the injection pump was also installed wrong when the car used alternative fuels. My belief is that the symptoms of that just might be less severe with alternative fuels. I do not remember a case of that ever being posted.


Members have even purchased these cars with the problem of the injection pump timed on the wrong stroke.

The term is right but the word phase might be confusing to some members. We pretty much made the wrong stroke the term most commonly used.

When you put the cylinder head back on, did you verify the TDC pointer was actually correct for # 1 piston all the way up and the cam timing was correct?