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Discussion Starter #1
Ok I have a 93 300 e-4matic with 189K. The thign will start fine when cold but once it reaches noirmal operating temp it just cuts off. No weird noises or clunks pr anything. IT will do it every time at 90 degress. I replaced the cap and rotor and the ignition coil pack. I don;t know what else to look at that coudl be causing it to just die. Please some oen help meee:surrender:
 

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Discussion Starter #3
honestly no one in here has never heard of anythign liek this? I did a search and can;t find anything. Please help me.
 

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Discussion Starter #5
I hooked a timing light up to it. And when it die son me I tried clickign the timign light on whiel tryign to start it and wasn;t gettign any spark. Whats a good parts website?
 

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Discussion Starter #6
also where is the crack shaft sensor located and where is the ignition moduel located
 

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Hello,

My engine (1996 300E, M103 on a w463) has developed the same problem as yours:

Easy to start first time and then after a 5 minutes, when warm, will either die by itself if left idling or, if the accelerator is pressed, begins to lose power, splutters and eventually it dies. It will then not restart until cold. But, while still cold, the engine seems to behave fine and has its usual power.

Replaced fuel filter and both fuel pumps checked OK. No difference.
Also, idle- air-valve OK, Temperature sensors OK, Ignition module OK, Cold-start enrichment OK (but probably not relevant)....

But, I found that the problem improved after running the car a number of times, but would get worse again if the car was left to stand for a week or so.

Until a few months ago, the car was always in regular, every-day, use and has been fine, although once it did do this a few years back after it had not been used for a few weeks, but was immediately OK again the same day. Recently, it's been off the road for a few months and this problem has developed.

Interested to see if you found the cause of your problem. I think it's not that uncommon, as I've seen a number of other threads with similar symptoms:

Mercedes Benz 300E Running Rough


It must be something deceptively simple......

My whole exhaust needs replacing as its still the original system and so I will also install new Lambda sensors when I do it. I think that the Lambda sensor may well be responsible, as the ECU looks at this when the engine is warm and the cold-start-enrichment is off. Still, its reading can be checked at Pin-3 of the X-11, 9-pin connector and I'll look at this next. Might also be sticky air-mass-flow sensor (?)
 

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1994 E320, 1993 300E
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Disconnect your catalytic converter and see if the problem improves. I have had 2 get plugged up and give similar symptoms.
 

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Discussion Starter #9
This morngin it wouldn;t even start so i think its the OVP relay. Is there an easy way to get the cat off with out cutting?
 

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Discussion Starter #12
I changed both fuses to no avail. When i took the relay off there was blue corosion on the bottom so i'm goign to get a new one within the next few days. If not i'm gonna change the ignition module. And if it still isn;t working a new high performance exuast system. And if that doesn;t work. I will do what they did on 6th gear in the last scence( take a bomb to it)
 

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'90 260E, '92 300 SEL
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The car can survive the blast. . . . .

Do you have new fuel filters? Fuel pump?

Check your fuel pressure regulator.
 

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Discussion Starter #14
yeah new fuel filter. The thing is parts for MBZ are so expensive. Anyoen know where to get cheap parts
 

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If your OVP is corroded that may play a part but I don't think it explains why the car works (worked) OK until temp reaches 90C.

Have you checked the Lambda sensor in the exhaust? If you disconnect it, the ECU will run with default settings and so you can easily see if that's the problem.

The OVP may well be related to no starting at all, as on some cars it controls the fuel-pump, ABS system etc.
 

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Discussion Starter #16
yeah when i disconnect it the car does not start. What is the lamba sensor?
 

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If your car has a catalytic converter, then it will also have a Lambda sensor.

Lambda is a term used for the ratio of fuel to air. If there is just the right amount of fuel for the amount of air present in the combustion chamber then all the oxygen will be burned and the mixture will not be too lean nor too rich. In this case, the (stoichiometric) ratio is equal to 1 and Lambda=1. Higher or lower values indicate either too much or too little fuel. The Lambda sensor is an oxygen sensor placed in the exhaust and it measures how much unburned oxygen remains in the exhaust. The readings from the sensor are fed back to the fuel injection system or engine ECU to increase or decrease the amount of fuel injected, until the ratio is correct.

The ECU ingores the Lambda sensor until the engine is warm because up until then, the cold-start enrichment valve is necessary to provide a rich mixture. Also, the sensor does not start to work until the exhaust reaches a temperature of about 300 deg. C. When the engine is warm, however, the ECU reads the sensor to continually adjust for the optimum fuel/air mixture.

If your engine does not start when cold, then you can suspect other things such as the OVP relay or cold-start valve, idle-valve, temperature sensors etc.

But if it does not start when warm, then the Lambda sensor may be faulty. In this case if it is disconnected, the engine ECU should revert to using some default settings, which will be OK, but not optimised. Therefore, if the engine starts (when hot) with the sensor disconnected, or, a better test: does not die as before when warm, with the sensor disconnected, then you can suspect a faulty Lambda sensor.

On the KE Ketronic system (III) the output from the Lambda sensor is available on one of the pins of the diagnostic connector (on the 9-pin X-11 connector, it's pin-3 and the output is a duty-cycle, which should hover at around 50%. Higher or lower values indicate lean or rich running.)


Hope this helps.
 

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Discussion Starter #18
know my car wont; start at all. But when i try to crank it it sound slike it almost wnats to start liek its about to than just dies( kind liek how it sounds with a fse missing from the OVP so i'm changing out the OVP. I will keep you guys posted as to if this fixes the problem
 

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86 190E 2.3L 16V, 2 95 320TE's, 02 S500
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Just curious. how often are you running your engine to redline? (when it was running as it should)

Jayare
 

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Discussion Starter #20
once in a while, prob more than i should, why what could that have to do with anything?
 
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