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Hi, so i got a 190e from -84 with a annoying issue. The car starts up fine and runs fine but after it gets warm ( usually 5-10 minutes) it starts stalling and will not respond at all. If you give it too much gas it just dies and it will have a hard time starting again, you can manage to move if you slip on the clutch with little gas but even then when i put in the third gear its too much and it dies. I basically can't drive it all. I really wouldn't like to spend too much money on it buying parts until i find whats wrong so i was hoping you guys could have an idea. Thanks in advance!
 

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89 190E2.6- 5-speed Manual, 95 E320 Sportsline-sold, 2001 E320 4matic Wagon-sold
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You have to find out if this is a fueling or ignition issue before throwing parts/money at it.
I'll assume this is a Bosch E-Jetronic emissions system and not a carburetor system.

Please tell us how many Km's on the engine.

For a car like this, I would say you will have to first find out if your fuel pressures (system and lower chamber) are correct and maintained (assuming Bosch E-Jetronic).

Just remember the Bosch system is heavily mechanical fuel injection, the electronic part just is just there to center the mechanical injection on average and also in "special" cases. So particularly when the car is warm, if you have running issues it is "most likely" in the mechanical fuel injection part of it or of course ignition components. Yes, of course there could be other electronic problems but those are outliers.

Of course you also have to chase down possible ignition component issues. But take it one at a time.

Fortunately, these cars are all not too difficult to work on and understand.

You need to know how to chase things down with a multimeter. It is all a futile effort if you can not do that.
This is your first post, so we do not know your background at all, sorry if you find some of these comments are too rudimentary for you.

Welcome to the forum

- Cheers!
 

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Discussion Starter #3
You have to find out if this is a fueling or ignition issue before throwing parts/money at it.
I'll assume this is a Bosch E-Jetronic emissions system and not a carburetor system.

Please tell us how many Km's on the engine.

For a car like this, I would say you will have to first find out if your fuel pressures (system and lower chamber) are correct and maintained (assuming Bosch E-Jetronic).

Just remember the Bosch system is heavily mechanical fuel injection, the electronic part just is just there to center the mechanical injection on average and also in "special" cases. So particularly when the car is warm, if you have running issues it is "most likely" in the mechanical fuel injection part of it or of course ignition components. Yes, of course there could be other electronic problems but those are outliers.

Of course you also have to chase down possible ignition component issues. But take it one at a time.

Fortunately, these cars are all not too difficult to work on and understand.

You need to know how to chase things down with a multimeter. It is all a futile effort if you can not do that.
This is your first post, so we do not know your background at all, sorry if you find some of these comments are too rudimentary for you.

Welcome to the forum

- Cheers!
Thanks. The gauge says 112 167km, sounds quite little to me... It's actually my first Mercedes and its funny cuse when i bought it it was running fine then like 2 weeks after this started happening and it seems like its getting worse. The previous owner changed the spark plugs, wires distributor cap and air filter not too long ago. The car sometimes backfires if you force it gas while its running poorly. I can hear the fuel pump go off when i turn the ignition on. Could it be any sensors? Coolant maybe? After a quick look i didin't even see any lambda sensor on the manifold... I heard that the OVP relay can cause trouble but that seems to be more of a cold start issue, and some say you cant test it with a multimeter.
 

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89 190E2.6- 5-speed Manual, 95 E320 Sportsline-sold, 2001 E320 4matic Wagon-sold
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You seem to need to sort out a lot of things.
What sort of back firing are you hearing? From under the hood (intake) or out the exhaust (tailpipe)
Makes a big difference in the diagnosis.

It is too soon to dive into emissions components testing. Honestly, if you have a good fuel distributor, fuel pumps running well and good injectors, you can disconnect the emissions system and the car will still run well when hot if the FD is in adjustment, except the emissions would suffer a bit. So you have to approach it from that angle.
 

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Discussion Starter #5
You seem to need to sort out a lot of things.
What sort of back firing are you hearing? From under the hood (intake) or out the exhaust (tailpipe)
Makes a big difference in the diagnosis.

It is too soon to dive into emissions components testing. Honestly, if you have a good fuel distributor, fuel pumps running well and good injectors, you can disconnect the emissions system and the car will still run well when hot if the FD is in adjustment, except the emissions would suffer a bit. So you have to approach it from that angle.
Sorry its definitely back firing out the exhaust.
 

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89 190E2.6- 5-speed Manual, 95 E320 Sportsline-sold, 2001 E320 4matic Wagon-sold
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Since exhaust backfires generally occur with a bad air fuel mixture or a pretty bad ignition timing, I would assume ignition timing is not changing between cold and hot for the time being.

The simplest check I would do is after the car warms up, remove the air filter and disconnect the EHA and tell us what happens next.
 

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Discussion Starter #7 (Edited)
Since exhaust backfires generally occur with a bad air fuel mixture or a pretty bad ignition timing, I would assume ignition timing is not changing between cold and hot for the time being.

The simplest check I would do is after the car warms up, remove the air filter and disconnect the EHA and tell us what happens next.
Thank you, i will try that.
 

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Discussion Starter #8 (Edited)
Since exhaust backfires generally occur with a bad air fuel mixture or a pretty bad ignition timing, I would assume ignition timing is not changing between cold and hot for the time being.

The simplest check I would do is after the car warms up, remove the air filter and disconnect the EHA and tell us what happens next.
Okay a little update: I got the engine warm to about 80c thats when it starts to mess around, unplugged the EHA cable and took the air filter off. Can't say if it were better or worse just about the same i suppose. I might add that after it dies and you wait a minute then start the car it runs fine for about 10 seconds then stalls again, which it did before too. Really getting on my nerves cuse its well, undriveable.
 

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89 190E2.6- 5-speed Manual, 95 E320 Sportsline-sold, 2001 E320 4matic Wagon-sold
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Prior to reaching 80c (or a little lower) the system does not do full lambda control. It enriches the fuel mixture and the amount of enrichment is inversely proportional to the coolant temp until the operating temp is reached.

So if the issue was the lambda control, when you disconnected it and nothing changed it seems the EHA is not involved with the running issue so much. That would be my argument. Or there could be two possibilities:

(1) EHA current is already around 0 and when you unplug it so nothing changed
(2) The EHA currrent is significantly different than zero when plugged in but making it zero does not change the outcome (running issues) so the running issue is independent of the air fuel mixture.

I would tend to lean towards (1).

If your car has the X11 port, you should measure the pin 3 to 2 duty cycle. See what it is up to. It maybe telling you things about the system (diagnostic). Do you have an X11 port next to the ignition control unit?

Did disconnecting the EHA cause your check engine light to come on? It should have but then again I do not have your model year.
 

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Discussion Starter #10
Prior to reaching 80c (or a little lower) the system does not do full lambda control. It enriches the fuel mixture and the amount of enrichment is inversely proportional to the coolant temp until the operating temp is reached.

So if the issue was the lambda control, when you disconnected it and nothing changed it seems the EHA is not involved with the running issue so much. That would be my argument. Or there could be two possibilities:

(1) EHA current is already around 0 and when you unplug it so nothing changed
(2) The EHA currrent is significantly different than zero when plugged in but making it zero does not change the outcome (running issues) so the running issue is independent of the air fuel mixture.

I would tend to lean towards (1).

If your car has the X11 port, you should measure the pin 3 to 2 duty cycle. See what it is up to. It maybe telling you things about the system (diagnostic). Do you have an X11 port next to the ignition control unit?

Did disconnecting the EHA cause your check engine light to come on? It should have but then again I do not have your model year.
I did not find such port on the car, also no check engine light on the dash. Is there any other things i could test?
 

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89 190E2.6- 5-speed Manual, 95 E320 Sportsline-sold, 2001 E320 4matic Wagon-sold
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The ports are just bolts on the FD. There are two of them, and you would need a male/male adapter to connect to a fuel pressure gauge.

But do the first things first. Measure your diagnostic voltage (average voltage or duty cycle) at the X11 pins 2/3.
See if it is static or fluctuating.

Do you not have an oxygen sensor? I think the early European models did not.
 

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Discussion Starter #12
The ports are just bolts on the FD. There are two of them, and you would need a male/male adapter to connect to a fuel pressure gauge.

But do the first things first. Measure your diagnostic voltage (average voltage or duty cycle) at the X11 pins 2/3.
See if it is static or fluctuating.

Do you not have an oxygen sensor? I think the early European models did not.
Theres no pin 3 at the x11 pins? Also no oxygen sensor.
 

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Discussion Starter #13
I've read a bunch of threads on different forums and found a few with the same symptoms and i read that a bad ignition coil can give such problems. What do you think about that?
 

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89 190E2.6- 5-speed Manual, 95 E320 Sportsline-sold, 2001 E320 4matic Wagon-sold
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Usually ignition problems are not temp dependent like yours but if the coil is acting up once it warms up, you can probably put an inline glow light to see if it gets dimmer as the car is warming up.
They go for about $10 at auto stores in the US. I suspect pricing in Finland maybe a little higher.
 

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89 190E2.6- 5-speed Manual, 95 E320 Sportsline-sold, 2001 E320 4matic Wagon-sold
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Also, you do not have lambda control via oxygen sensor but you still should have an EHA.
You should measure your EHA current and see what is going on there particularly when the car warms up.

Report on that and let's see if there is any unusual activity.
 
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