Uncooperative OM617 start-up (helping a friend) - PeachParts Mercedes-Benz Forum

Jetmugg · #1 02-09-2015, 10:36 AM

OK - here's one I haven't figured out yet.

I have a female friend who owns an '84 300D. The car used to be a somewhat daily driver. That was 5+ years ago. It's been sitting in her unheated, leaky roof (no electricity) single garage since then. It is damp to the point of having condensation under the hood of the car. It's a toxic environment for an automobile.

The last time the car ran was when I went over and jump started it for her about 4 years ago.

I already told her that if she really wanted to get it going, I'd tow it away and bring it to my house, which has all the amenities in my garage.

So, anyway, she is in the mood to get it running again, so I volunteered to help. On my first trip to her house, I brought the battery from my 190D 2.5T (because I knew hers was bad). I also brought all the tools I thought I'd need for the job.

Put the fresh battery in, cycled the key, and it sounded like it "almost" would start, but didn't. Checked the glow plugs, and at least 3 of them were working (I couldn't get a good read on the other 2).

I cracked the injector lines loose at the injectors and cranked some more. They got wet, but never really "spurted" fuel like I had hoped.

Tried the IP primer pump (the old style one), and it started leaking like a sieve. At that point, I knew that our chances were slim to get it started on that day, but tried a bit more anyway.

Next move - I ordered a new Bosch primer pump, and asked her to buy a brand new battery. The old one wouldn't hold a charge.

I went back to her place this weekend, installed the new primer pump, pumped it maybe 100 times, installed the new battery and let it crank a bit. It never started. I broke the injector lines loose again, more cranking, more primer pump pumping.

I only got 1 line to really "spurt" fuel with the injector nuts loose. The others would get wet, but not as much as I think they need to.

After some more cranking, the starter circuit started acting up. I used a momentary remote starter switch in combination with her cycling the ignition key for the GP circuit. Still no starting.

I'll continue on the next post.

Steve.

Jetmugg · #2 02-09-2015, 10:42 AM

Since the car ran decently before it was parked, I'm pretty confident about the compression.

With at least 3 GP's working, I expected to at least get some smoke out the tailpipe, but got virtually nothing.

My big concern is that I don't think the IP is properly primed.

For my next trip to her place, I plan to completely back-off the injector line nuts from the injectors to get a better view of how much fuel is coming out of the lines during injection.

I'm hoping for some suggestions on how to ensure the pump is fully primed.

After sitting for so long, is there anything on the pump rack which might be stuck, preventing fuel delivery? If there are any other ways to "force" a prime, I'm open to those ideas.

I had considered putting a small electric pump in the supply side fuel line, but don't want to mess with that while the car is still at her crude garage.

Steve.

vstech · #3 02-09-2015, 10:53 AM

step one.

change the oil.

step two, adjust the valves.

step three... get a good read on all the glow plugs. and change them all if any are ify.
when changing the valves, get a glow plug reamer, and clean out the holes.

I bet it fires up instantly after that.

mach4 · #4 02-09-2015, 10:58 AM

Step four, change the filters

Step five, make sure you've got good fuel. In fact might as well just set up to do a diesel purge - it could probably use it

With as much moisture as you're seeing, who knows how much water you've got in there, and how much growing stuff is also present.

Jetmugg · #5 02-09-2015, 11:21 AM

Yeah - I've got to have a very frank talk with her about this car. If she and her 20-something son are really committed to getting this car back on the road, I'll be happy to help.

To do it "right", I'd haul it off on my trailer, put it up on jackstands in my warm, cozy garage, and make it right. I have enough of my own projects right now, but I'm normally willing to help someone with a car like this.

While at her place, I'm trying to go after the most fundamental items which may be preventing it from starting.

I haven't dug into the fuel system beyond changing the primer pump. Pulling and changing the main and secondary filters would be a move in the right direction.

I'm going to focus on the items that could directly prevent it from starting at this point. Although the valves probably need to be adjusted, I just don't have the feeling in my soul that improperly adjusted valves are at the root of the non-start condition.

I hate to see a car with as much potential as any W123 diesel sit and rot away.

Steve.

Maxbumpo · #6 02-09-2015, 11:28 AM

Quote:

Originally Posted by Jetmugg

It is damp to the point of having condensation under the hood of the car. It's a toxic environment for an automobile.

Steve,

Don't use ether or starting fluid; there is a very slight but real risk of cracking a pre-chamber.

The water is a big problem. As already mentioned, there is almost certainly water in the fuel tank and in the oil sump. I'm also concerned that water may have condensed inside the cylinder walls and started rusting there.

The water in the oil sump may not need to be addressed yet, an interim measure would be to drain a quart out of the sump (and that should also drain out the water in the bottom) and then replace with fresh oil. I would not invest further in an oil change until after you've got the engine started and have an idea of the overall health of the engine.

As already suggested, change the fuel filters, fill the new main filter with clean fresh fuel. In the engine bay, set up a temporary fuel source and run the supply and return lines into that. Watch for water coming out of the return line initially - may want to put the return line in a separate container so you don't immediately contaminate your new fuel source with water.

After that, pump the accelerator pedal a time or two to make sure the fuel rack is free in the injection pump. I'd recommend that you hold the accel. pedal to the floor while you crank the starter over. Perhaps leave the injector lines loose while doing this to get better flow from the hard lines. The fuel leaking from the hard lines at the injectors will never really squirt out, it needs to build pressure against the injector to get that squirt.

If the block heater and cord are present, you can plug those in to help build heat.

Worst case scenario: Pull start the car. The procedure is in the owner's manual.

funola · #7 02-09-2015, 11:53 AM

In order of priority:

1. All glow plugs must be good to have a good chance to start in 30 F temps.

2. New battery- that's good. Is the starter and wiring healthy? Do you know what RPM it's cranking at? 160 to 180 RPM is good. Below 140 RPM is marginal and probably won't cut it, especially with 1 or more bad glow plugs.

3. Loosen all 5 injector line nuts and make sure fuel is coming out of all 5! I think The Don have a 240D that sat for many years and spent about 6 months trying to get it started and in the end (after trying many other things), found that fuel was coming out of only 1 injector line. I think he had 3 bad delivery valves and after changing to 3 good used ones, it started and ran fine.

I wouldn't bother with the valve adjustment for now since it ran well last time you got it started.

ps. put a clear line in place of the cigar hose (return to tank), if you see air bubbles after it starts and ran a while, clean the tank strainer and change both fuel filters and dose it with Startron.

Jetmugg · #8 02-09-2015, 12:49 PM

OK - I appreciate the input, and there are definitely some good ideas rolling in. I have already considered getting a separate jug of diesel, using a length of new fuel line and attempting to start the car from the jug and returning to the jug, with fresh filters.

Tow starting is another option, although it's in a decidedly urban neighborhood right now. I'd feel better about doing that out-of-town a bit, where there's more room to run and no stop signs.

I don't have a good way to measure rpm's while cranking. It sounds like it should be spinning fast enough to start. What's got me scratching my head is that it doesn't even sound close to starting.

I definitely need to check further on the fuel delivery situation. My gut tells me that not getting fuel to and through the injectors is the root of the no-start condition.

Steve.

vstech · #9 02-09-2015, 12:51 PM

Quote:

Originally Posted by Jetmugg

Yeah - I've got to have a very frank talk with her about this car. If she and her 20-something son are really committed to getting this car back on the road, I'll be happy to help.

To do it "right", I'd haul it off on my trailer, put it up on jackstands in my warm, cozy garage, and make it right. I have enough of my own projects right now, but I'm normally willing to help someone with a car like this.

While at her place, I'm trying to go after the most fundamental items which may be preventing it from starting.

I haven't dug into the fuel system beyond changing the primer pump. Pulling and changing the main and secondary filters would be a move in the right direction.

I'm going to focus on the items that could directly prevent it from starting at this point. Although the valves probably need to be adjusted, I just don't have the feeling in my soul that improperly adjusted valves are at the root of the non-start condition.

I hate to see a car with as much potential as any W123 diesel sit and rot away.

Steve.

Look...

I understand you feel focusing on starting issues are most important...

NOTHING short of a dead battery will slow a good start faster than a set of NEVER ADJUSTED valves...
seriously. change the oil FIRST!!!

then spin the motor over a few times and get the fresh oil in all the places.

then pull the linkage and valve cover, and adjust the valves. you could be losing 100psi per cylinder from loose valves. believe me... the valves being in spec are extremely important to getting the motor to fire.

you have fuel to all injectors. not SPRAYING, but no bubbles... that's fine to start the car. move on to the glow plugs.

test them with the ohm meter, any that are above .8 ohms just replace them.

from there you can look into other issues. start with the basics. you do NOT want old oil being circulated through the motor! it will destroy the motor especially if you crank for a while and then give it a few days because you are busy, or she is...

heck... first on my list may be to put a tarp on the roof... if the place is raining inside...

Jetmugg · #10 02-09-2015, 12:52 PM

Oh - I definitely won't use Starting Fluid, either. I know better.

It's really a sad state of affairs. I can tell that the owner thinks the car is in much better condition than it really is.

The best thing for the car will be to get it running and driving before it gets any worse.

Steve.

Jetmugg · #11 02-09-2015, 12:55 PM

Duly noted. I need to send her a message to figure out if she and her son are really "In it to win it". I'm OK with volunteering some of my "spare" time to this project - I hate to see any car sit and fade away.

She and her son are probably qualified to change the oil and "maybe" adjust the valves.

Steve.

Jetmugg · #12 02-09-2015, 12:56 PM

I have also considered running a compression check on all 5 holes at the same time as changing the glow plugs.

Steve.

funola · #13 02-09-2015, 01:13 PM

Do valves go out of adjustment from sitting??? Don't think so. I've started diesels that sat for more than 10 years by just putting in a new battery. It smoked a bit at first then cleared and idled fine. As long as the fuel system was tight, i.e. no air got in and it is 100% filled with diesel, it should start.

charmalu · #14 02-09-2015, 10:56 PM

Quote:

Originally Posted by funola

Do valves go out of adjustment from sitting??? Don't think so. I've started diesels that sat for more than 10 years by just putting in a new battery. It smoked a bit at first then cleared and idled fine. As long as the fuel system was tight, i.e. no air got in and it is 100% filled with diesel, it should start.

We don`t know at this point when the valves were done last, even if it was
running when it was parked.
Adjusting them will scratch one more thing off the list of no start.

The clear line replacing the Cigar Hose is a good idea to see if it is sucking air.

I had a problem starting a Nissan SD-22 Diesel engine that had sat for a while.
Finally swapped an IP from another spare engine, and she started right up.
So could be the Delivery valves like mentioned.

Charlie

Lucas · #15 02-10-2015, 01:49 AM

+1 in adjusting valves. It's not one thing. It's a bunch of shady things adding up.

If it sat, the rings may be frozen. You can look up MMO soak on here. I'm not a huge fan. Towing and forcing it over seems to make them pop.

Oil change also. You can pour a quart of MMO in doing a soak and run that mix for the first 3k miles.

I would adjust valves and then check compression. Low compression reading will tell you to adjust them anyways.

I've never understand why some motors can handle either and some can't. If you use it just don't spray to heavy.

If you are worried the pump is froze up, just remove the inspection plate and make sure everything is moving. Just look while cranking it with it open. You need a mirror.

Towing. Can't say enough good things about it. Lol.