OM603 not starting - PeachParts Mercedes-Benz Forum

martureo · #1 05-06-2020, 05:40 PM

Long story short, I have a OM603.960 from an 1987 300TD. The 87 was t-boned at ~140k and I pulled the motor to put in my w123 wagon. The engine had been sitting for some time and I turned it over occasionally by hand.

I've been trying to start it for the last couple of days with no luck.

I pulled all the computer bits off it and am running it on manual control.
crossover and intake are off for simplicity
It's got a fresh battery hooked up and a trickle charger to help crank it for longer periods.
I don't have any diesel sitting around so I've been trying to start it on a few cans of LubroMoly Diesel Purge
I filled the fuel filter (secondary) and am running the feed/return lines into a Gatorade bottle
Glow plug relay is working and all glow plugs are new
I cracked all the injector lines at the injectors and fuel is seeping out

A tech friend of mine said I should try to help it along with some ether or brake clean in the intake. I tried this and got it to hiccup once.

I've owned several 617s and a 606 before, but this is my first 603. I feel out of my element and this thing is driving me nuts.

Any other ideas other than keep cranking?

Usaguy · #2 05-06-2020, 05:44 PM

Quote:

Originally Posted by martureo

A tech friend of mine said I should try to help it along with some ether or brake clean in the intake. I tried this and got it to hiccup once.

Never do that on an engine with glow plugs and if you do then don't power them cause you can damage the motor

martureo · #3 05-06-2020, 06:55 PM

Quote:

Originally Posted by christuna

Never do that on an engine with glow plugs and if you do then don't power them cause you can damage the motor

He's an experience MB tech and said I should do it to get a diagnostic hiccup.

greazzer · #4 05-06-2020, 07:44 PM

A little bit of starter fluid now and then shouldn't cause any issues. Using it like daily mouthwash is a different story.

Ben - Did you park the car on a slight incline for a while ?

martureo · #5 05-06-2020, 08:44 PM

Quote:

Originally Posted by greazzer

A little bit of starter fluid now and then shouldn't cause any issues. Using it like daily mouthwash is a different story.

Ben - Did you park the car on a slight incline for a while ?

Well, the rear suspension is not currently pressurized (SLS) and it's up on a few blocks in the front. So essentially its parked with the front inclined.

Diseasel300 · #6 05-06-2020, 10:37 PM

Is the "Stop" lever on the IP sticking nearly straight up? While cranking, do you have fuel flowing back into the bottle through the return fuel line? The fuel system on the 603's is pretty much self-bleeding. The fuel heater thermostat is a very well known source of air ingress and should be the very first thing bypassed for troubleshooting. Hook your fuel line directly to the inlet port on the lift pump and give it a healthy 30-45 second crank, see if it primes itself.

if6was9 · #7 05-07-2020, 01:05 AM

Did you have it running before you pulled it and swapped it?

Couldn't hurt to plug in the block heater, a warm 603 ought to tick over pretty quick and easy like as long as it's getting fuel.

With the intake off it should be easy to spray some WD40 into the intake ports. With known administration of enough fuel it should tick over or at least cough a few times if the engine is not getting fuel from the nozzles.

martureo · #8 05-07-2020, 04:27 AM

Quote:

Originally Posted by Diseasel300

Is the "Stop" lever on the IP sticking nearly straight up? While cranking, do you have fuel flowing back into the bottle through the return fuel line? The fuel system on the 603's is pretty much self-bleeding. The fuel heater thermostat is a very well known source of air ingress and should be the very first thing bypassed for troubleshooting. Hook your fuel line directly to the inlet port on the lift pump and give it a healthy 30-45 second crank, see if it primes itself.

Stop lever up.

I can't tell, as I'm cranking from the key, but fuel is moving in the bottle.

I resealed the fuel heater thermostat and it has all new lines, but I'll bypass it to see if that helps.

Quote:

Originally Posted by if6was9

Did you have it running before you pulled it and swapped it?

Couldn't hurt to plug in the block heater, a warm 603 ought to tick over pretty quick and easy like as long as it's getting fuel.

With the intake off it should be easy to spray some WD40 into the intake ports. With known administration of enough fuel it should tick over or at least cough a few times if the engine is not getting fuel from the nozzles.

I tried to get it to turn over in the wrecked car but the starter motor had been heavily damaged in the accident and tried to launch itself into low earth orbit when energized. No luck there.

The cooling system isn't fully plumbed yet, so the block heater wouldn't do anything.

I sprayed some brake cleaner and got a few hiccups. I'll try again.

greazzer · #9 05-07-2020, 05:39 AM

There was a thread a while back regarding a running OM603 which turned into a non-running OM603 and being parked a while on an incline had something to do with it. I’ll start rummaging about for it

martureo · #10 05-07-2020, 05:40 AM

Quote:

Originally Posted by greazzer

There was a thread a while back regarding a running OM603 which turned into a non-running OM603 and being parked a while on an incline had something to do with it. I’ll start rummaging about for it

I did a search yesterday for non starting 603s and found that same mention, but there was no reply as to why or if it changed anything.

Diseasel300 · #11 05-07-2020, 10:12 AM

You may just be air bound. While the 603 is self-priming, it can be a pill if the fuel system is totally dry. Try the following:

1: Bypass that stupid fuel thermostat.
2: Unbolt the lift pump and operate the plunger until you have fuel streaming from the return line. You can just plunge it in and out on the cam, which is the easiest method I've found.
3: Loosen the hard lines on cylinders 4, 5, and 6.
4: Crank the engine until you have fuel spurting out of the lines on 4, 5, and 6.
5: Tighten down the hard lines, give it a good glow, and try cranking. It should fire up if the compression is good and the fuel system is pumping.

When it finally fires up, it may be hitting on one or two cylinders only. If it is and keeps trying to stall, give it about half throttle and keep trying, it should burp the air pretty quickly once it starts firing.

martureo · #12 05-07-2020, 12:14 PM

Quote:

Originally Posted by Diseasel300

You may just be air bound. While the 603 is self-priming, it can be a pill if the fuel system is totally dry. Try the following:

1: Bypass that stupid fuel thermostat.
2: Unbolt the lift pump and operate the plunger until you have fuel streaming from the return line. You can just plunge it in and out on the cam, which is the easiest method I've found.
3: Loosen the hard lines on cylinders 4, 5, and 6.
4: Crank the engine until you have fuel spurting out of the lines on 4, 5, and 6.
5: Tighten down the hard lines, give it a good glow, and try cranking. It should fire up if the compression is good and the fuel system is pumping.

When it finally fires up, it may be hitting on one or two cylinders only. If it is and keeps trying to stall, give it about half throttle and keep trying, it should burp the air pretty quickly once it starts firing.

Bypassed thermostat.

Cracked all fuel lines (again) and got fuel through all.

Glowed and cranked. Nothing.

Bit of brake kleen in the intake and it turned over a few times. It doesn't want to keep running.

I'll keep trying, but I'm getting the feeling something else is up. I've got fuel coming into my return bottle steadily and fuel at all the injectors. I'm wondering about timing, or injectors being fouled. The previous owner guaranteed that everything was fine before the accident, but I'm not sure what the accident could've done.

Diseasel300 · #13 05-07-2020, 12:40 PM

Try giving it half-throttle and see if it makes any appreciable difference. The mechanical idle setting can be so low that the engine doesn't want to run. They're supposed to be set to 550RPM or so, but my 350SD came to me with the idle stop set at ~400 RPM, the engine would run (it's a healthy example) but just barely.

martureo · #14 05-07-2020, 02:31 PM

She ran!

Couple rounds of half throttle, a bit of brake cleaner and continuous cranking and she ran. Decided to try it again without any brake cleaner and it took about 20 seconds of cranking but she started on her own.

https://youtu.be/uo89a3xE258

Now on to the cooling system.

martureo · #15 05-08-2020, 01:35 PM

I should have thought about this sooner.

After a really tough time starting and then a terrible time getting it restarted even a few minutes later it should have hit me what was wrong.

Why would I not be getting fuel from the return line after I had it started? Why, with a full remote can of fuel and without disconnecting anything would it sound like there was no fuel?

Lift pump.

Diseasel300 already mentioned that I should pull it and test it, but I ignored it when I was getting fuel from the cracked injector lines.

I've ordered a bunch of o-rings and will be replacing them using this thread as a guide. (If anyone needs any, ask)

http://www.peachparts.com/shopforum/diesel-discussion/383438-om603-602-601-lift-pump-re-seal-o-rings.html