PeachParts Mercedes-Benz Forum - 1999 E300 intermittent shut off

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Quote:

Originally Posted by TimFreeh (Post 4293851)

It's almost certainly some sort of electrical issue. Could be in the wiring harness, ECU or the injection pump itself. The fact that it can run for 2-3 weeks is a huge problem for diagnosis - it's a show-stopper for anyone but the most die-hard OM606 enthusiast.

The diesel injection system used on the OM606 turbo is the last of the in-line injection pumps that can trace its roots and basic operating principles all the way back to the 1930's and 1940's. However it also has the unfortunate 'feature' or 'evoluiton' where the pump rack is under direct computer control and supervision. If the computer isn't involved the car is inoperable.

As such it kind of has the worst of both worlds, you have to have computers in the process to run the car BUT you still have all the disadvantages of the early IDI engines, prechambers, only one injection event per combustion event, relatively imprecise timing, inability to alter fueling for each injector ect, ect that the later CDI engines nicely provide for a huge bump in power, refinement and economy.

The shop in Milwaukee is doing exactly what should be done, its certainly telling the the Mercedes dealer doesn't want to touch it.

The only plausible path I can see to providing a fix is to find another E300D that runs correctly and start swapping (one at a time) wiring harnesses, ECU and then the actual IDI injection pump. I'm not 100% sure of cars of this vintage but the ECU swap might also involve the EIS key and the steering column lock.

You could certainly disassemble things and look for cold solder joints or fractures in circuit boards and wires in the harness but this is, to say the least, a needle-in-the-haystack kind of task and if the issue is actually a problem related to a capacitor or a transistor that drives the rack position motor you'll never find it with a visual inspection. At least with the needle-in-a-haystack metaphor there is a needle to be found with a visual inspection of the haystack.

If you're paying a competent professional mechanic to do this sort of work you're going to exceed the value of the car in about 3 days. It would all have to be time and materials work with no guarantee of success.

Sorry..... but that's all I've got.

If you decide to throw in the towel there is one other thing you should be aware of - the OM606 turbo is a very popular engine for engine swap projects. It can be easily retrofitted with a fully mechanical pump from and OM603 and make huge HP. There are aftermarket companies that provide tuning, performance upgrades and transmission adaptors and its very much in demand. Not sure what they're selling for but I see lower mileage examples frequently listed for 3-4K dollars. Someone that was going to swap a mechanical pump wouldn't care if the current computer controlled system was flakey. Don't sell the car for trade-in value if you decide to move on.

Tim- good info-
wts-- Couldn't packerfan swap in Mechanical pump and some nifty updated ECU to go with it as a fix??? I assume this would eliminate a few things that could be causing his stalling?

Would the above swap interface with EIS/Steering lock??? Curious cuz I own a couple of nice w210 TDs.... and sure would like to know solutions.

Thanks to all of you for your help. I will be putting the car in storage for the winter and try to figure out what to do with in the spring. I'm just not ready to give up on this beautiful car!

Quote:

Originally Posted by wallbenz (Post 4294038)

You certainly could swap the IDI pump for a purely OM603 mechanical pump, it would not interface with the EIS lock at all.

Such a modification would obviate the entire IDI ECU and remove all engine specific information from the CAN. This would have totally unpredictable effects on all other systems that interface with the engine like the 722.6 transmission and the ABS and ESP systems. I have no idea how such a setup would work or even if it would work at all. In addition the 'CHECK ENGINE' light would be permanently on - many states now to OBD checks as part of the emissions checks - the deletion of the ECU driving the injection pump would be an instant fail.

There is no magic ECU that could be substituted - to build one would be an epic task.

Quote:

Originally Posted by TimFreeh (Post 4293552)

Well I'd guess its because he has a job, family, life commitments that set things up so that he can't be on-line waiting for your latest diagnostic remarks?

Good grief, take a chill pill.

You offered no help at all, and I did try to help but I can't do anything when the guy doesn't even want to answer any questions. And fact is I bought E300 with same exact intermittent no start issue and I was able to find the problem.

Quote:

Originally Posted by Haken (Post 4294410)

Hello Haken, I'm sorry I asked for help while the car was at a shop 100 miles away from me. I will be picking the car up this weekend and when I get it home I will be sure to let you know what the tachometer needle is doing when the car does not want to start. You said you bought an E300 with exact intermittent no start issue and you were able to find the problem. You are the last person I need mad at me for not answering questions. Again I apologize and I will keep in touch with you once I have the car in front of me.

Quote:

Originally Posted by Haken (Post 4292404)

when it does not want to start, do you see the RPM needle move up at all from 0 while cranking?

Where are you Haken?

Quote:

Originally Posted by Haken (Post 4292404)

when it does not want to start, do you see the RPM needle move up at all from 0 while cranking?

No, RPM needle stays at 0 while cranking.

Quote:

Originally Posted by Haken (Post 4292404)

when it does not want to start, do you see the RPM needle move up at all from 0 while cranking?

No, the RPM needle stays at 0 while cranking.

Hi Packerfan, did you make any headway on the issue? I think I am in a similar situation to you on my 99 e300d. I am having an intermittent no start issue , or rather start and immediately stall. When it starts it runs and drives great. When it stalls, it will crank, and actually start, begin to shudder, and then stall after 2 or 3 seconds. During this brief time that the engine starts, both 1. the starter stays engaged, and 2. the RPM needle doesn't register any rpm. I can think by the sound I should see at least 500-1000 rpm. I need to confirm, but I think the sov is not actuating at this time as well. But when it runs, I can turn the key and hear the preglow and sov relays click. I've done all the O-rings with Teflon, as well as installed an aux electrical fuel pump, filter change etc. So I don't think air in the fuel is an issue. I am getting no CEL codes either. So I am wondering if there is something causing the ecm to intermittently not see RPM on crank and start up? And would that cause the ecm to disable the sov at that time? thanks in advance.

This is much later, but I'm posting as it may help you Packerfan, or someone else. I have a 99e300 188,xxx. Intermittent no start, with no DIL trouble codes. I added a rear electric fuel pump and replaced all o-rings with viton, as well as by passed the pre filter and added inline filter further towards tank. I did this because it looked like I was getting air in the lines when It wouldn't start. None of this fixed the issue. I had all good glow-plugs, and controller connection and harness seemed good. SOV tested good, and wires to it tested good. But when I had the no start issue I could see that the sov wasn't being activated by the PCM (causing what looked like air, but more than likely just fumes pulled out of the fuel by vapor pressure, and vacuum). Also when I had no start it would crank, and start just a little bit, but even when I let of the key, it would continue to crank until ecm timeout. When this happened I noticed, I got not rpm on the gauge. Now you may see where this is heading. I read on a forum that the crankshaft position sensor could cause a crank no start. So on my live data using a scan tool, and with a multimeter measuring the ckp ecm pins (during cranking you should see some ac voltage maybe less than a volt). When the car wouldn't start I wouldn't see rpm on my scan tool and I got 0vac on the multimeter (when it would start you would see about 2 volts on the old ckp, and on the new one over 3 at idle usually). I suppose that if the ECM doesn't see crank signal then it disables the sov? It would be better to use a scope on this to see any weird signals, but I didn't have one, and a multi meter proved to be enough to diagnose this. Anyhow I replaced the ckp sensor with a matching bosch part number, and the car now starts normally every time for over a week now. I was using Mitchell's erepair database....it has very little info on how the ecm controls cranking, so it was next to useless, but this is the best I can figure, is the the ecm is looking for ckp signal during cranking and without it, it may disable the sov.