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Discussion Starter #1
I have a 1986 190e that was brought over from Germany and “federalized”. It has starting a problem. It hits immediately, then stalls in about 2 seconds. If you do this about 4-5 time she runs, then runs fine once up to temperature. It starts so well, I feel it must be a fuel problem, not a spark problem.
I am not one to replace things and see no change in the problem, I would rather troubleshoot.
The car has three sensors right in front on top that detect coolant temp. The one nearest the firewall seems to be the thermotime switch. It has two weird black prongs sticking up. I think it is doing its job as when she gets running in the cold and then I remove a wire from the switch, it tries to kill. So I think this sensor is operating the cold start valve correctly. Also, I can measure a resistance between the two contacts, about 4-5 k ohms.
The next sensor in line is also, a two pin job. I took it off, and there is no continuity through the switch, but it said 95/100 C on it. That leads me to believe it is an overheating indicator swithc I don’t think it has anything to do with fuel control. I could have checked it by heating it up, but did not.
The third sensor is a single pin job. I think this is the coolant temp sensor and I believe it is supposed to change resistance as it heats up. As I understand it, the R will go down as the coolant warms up. However, I get no continuity from the pin to ground, it seems to be open.
Question is, am I understanding this last sensor correctly, and should I measure a resistance in it? Does it provide a signal to the fuel system?
Any input would be appreciated.
 

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2021 SL770
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Welcome to BenzWorld! I'll slide your query down to the W201 section, where you're far more likely to garner a helpful response from some like-minded enthusiasts. You might also consider completing your user profile, many find that information helpful in regard to providing you with the best possible response.
 

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If it is the coolant temp sensor, then you should see your temp gauge moving in the instrument panel as engine heats up, very simple, or you can attach it to a rheostat (volume control) and check the temp gauge moving

the second sensor is the overheat sensor which turns on the radiator electric fan, the first sensor is the thermotime sensor which activates the cold start injector for a certain period of time.

As far as I know, the temp gauge does not provide a signal to FI system
 

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'87 190E 2.6
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There is another sender that provides engine temperature to the ECU. If the temp sender has failed the engine will remain in closed loop forever - it will (should) not cause this problem - it wil however effect fuel consumption as the car will run rich all the time.

Questions:
Which engine is it?
Have you removed the ISV and cleaned it?
Have you checked for vacuum leaks? (everywhere).
Does the fuel metering plate return to rest when the car is off (key on).
Have you checked fuel pressure?
 

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I also have an '86 190e..same exact problem!!! Starts perfectly each morning. Drive about one block, then it starts to cough and gasp, and run EXTREMELY rich. Sometimes goes away in 15 seconds, now lasting 3 minutes or more. Have to switch off, its very hard to start, then sudddenly it clears itself and runs like a top all day, as long as you dont stop for more than 3 hours.
This has gotten very dangerous, when getting on the freeway, as it stalls, gasps, chokes and quits, you have to pull over, and try to get to side.
I have replaced in last three weeks: fuel filter, air filter, spark plugs, rotor & cap and thermostat (the stat was definitely defective, aas it would not lift the guage even after an hour of running, it now does, and it seemed to me that it was a cold sensor problem, like the engine was not warming up, so some electronic switch was telling something on the engine to keep it is cold-start, and thus extra-rich startup mode. Replacing stat seemed to help, but the choking and gasping is getting much worse last several days.

What is this? Need help!

Thank You.

Makoa
[email protected]

.
 

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Discussion Starter #6
There is another sender that provides engine temperature to the ECU. If the temp sender has failed the engine will remain in closed loop forever - it will (should) not cause this problem - it wil however effect fuel consumption as the car will run rich all the time.

Questions:
Which engine is it?
Have you removed the ISV and cleaned it?
Have you checked for vacuum leaks? (everywhere).
Does the fuel metering plate return to rest when the car is off (key on).
Have you checked fuel pressure?
Thanks,

It is the single cam 2300
What is the ISV
I will check better for vacuum leaks
I will check the matering plate
No, I have not checked fuel pressure, where is best place to get in and do that.
 

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1996 Volvo 855GLT, 1993 MB 190e 2.3 8v, 1998 Subaru Outback SUS, 1991 BMW 525, 1998 MB C230
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read the epic stalling thread.
 

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1990 190e 2.6l Calif. auto 1987 Ford F150 4.9L Calif. man 4OD 4X4 2013 Suzuki C50 Crusier
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A computerized car starts up in open loop and runs by set values and after it heats up and the 02 sensor is hot the computer gos into close loop and now will look at the 02 sensor and other sensors to control fuel and spark. ( always adjusting )
 

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1992 190E 2.6
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Definitely read the epic stalling thread

I have a 1992 2.6 which I have owned since new. I had rough idle in gear and bad hesitation. Also what has been described to me as the idel "hunting". IT would kind of drop out at idle and then catch back up never really stalled all together, but got bad and would rev up and down pretty eratically at idle and idled really rough. Aorund 100 at start and then 600 to 700 when hot under load.

I had already replaced coil, plugs, rotor and cap. Wires are a couple of years old. All were really needing replacement and coil failed so no loss there.

From the thread a got a lot of good information. So far I have replaced a couple of the breather hoses, vavle cover to intake manifold, ICV to air flow meter and valve cover to air cleaner body(I still can't figure out how to get to the one which goes from the ICV to intake - funny looking has a lot of bends in it if anyone knows let me know what I have to take off). No real difference.

Took off the ICV and cleaned it and it got a little better. Also cleaned the plate which moves up and down inside the air intake under the air cleaner and that helped a little.

I replaced the OPV relay, made no difference.

Last week I replaced the oxygen sensor and it got a lot better. I am not doing my happy dance yet, but it is much better. I am sure I never replaced the oxygen sensor and I have 220K miles. Even seems to shift better.

I still have the fuel filter to do, which I can not remember changing either. Maybe this weekend. Anyway all of that stuff was around $250 and everything, but the OVP should have been repalced anyway just for maintenance.

Hope this helps, the stalling thread helped me a lot.
 

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1990 190e 2.6l Calif. auto 1987 Ford F150 4.9L Calif. man 4OD 4X4 2013 Suzuki C50 Crusier
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Start out buy changing the fuel filter and also clean the air intake plate just below inside the opening. disconnect the battery for maybe 30 mins and after doing the work hook up the battery and let Idle to warm up then put in drive for a min. drive car also turn on a/c for a little when driving . then turn off a/c and drive a little more to your drive way and let Idle in drive for a few mins then in park for a few mins. ( this may help as the computer trys to do a relearn for settings and Idle ).
 

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Discussion Starter #11
I have a 1992 2.6 which I have owned since new. I had rough idle in gear and bad hesitation. Also what has been described to me as the idel "hunting". IT would kind of drop out at idle and then catch back up never really stalled all together, but got bad and would rev up and down pretty eratically at idle and idled really rough. Aorund 100 at start and then 600 to 700 when hot under load.

I had already replaced coil, plugs, rotor and cap. Wires are a couple of years old. All were really needing replacement and coil failed so no loss there.

From the thread a got a lot of good information. So far I have replaced a couple of the breather hoses, vavle cover to intake manifold, ICV to air flow meter and valve cover to air cleaner body(I still can't figure out how to get to the one which goes from the ICV to intake - funny looking has a lot of bends in it if anyone knows let me know what I have to take off). No real difference.

Took off the ICV and cleaned it and it got a little better. Also cleaned the plate which moves up and down inside the air intake under the air cleaner and that helped a little.

I replaced the OPV relay, made no difference.

Last week I replaced the oxygen sensor and it got a lot better. I am not doing my happy dance yet, but it is much better. I am sure I never replaced the oxygen sensor and I have 220K miles. Even seems to shift better.

I still have the fuel filter to do, which I can not remember changing either. Maybe this weekend. Anyway all of that stuff was around $250 and everything, but the OVP should have been repalced anyway just for maintenance.

Hope this helps, the stalling thread helped me a lot.
Where to I find the stalling thread
 

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1990 190e 2.6l Calif. auto 1987 Ford F150 4.9L Calif. man 4OD 4X4 2013 Suzuki C50 Crusier
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Well I dont think you should go to that thread because I think it is just not a good one to learn from. the only thing you will learn from it is how to be a parts changer and spend a lot of money and still have the car broken . The best thing maybe is to look for vacuum leaks and broken hoses, clean things and make sure sensors are pluged in good. maybe unplug and replug then in to make good contact. If you are going to work on your own car you will need a somewhat good ( DVOM ). and read before just replacing parts.
 

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1990 190e 2.6l Calif. auto 1987 Ford F150 4.9L Calif. man 4OD 4X4 2013 Suzuki C50 Crusier
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With a DVOM you can take the coolant sensors out of the car clean them and check the OHMs and get a chart and check it by heating it up to see if it is reading correctly. just like checking a thermostat on the stove with a temp gauge. you can check plug wires with OHMS and at night in the dark look for sparks jumping from wires to ground. Other words learn to be a tech not a parts changer.
 

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I still think that thread is a good resource for what the potential problems could be. I agree how ever don't just replace things willy nilly. As I mentioned, my calculation was based on things that should have been replaced anyway. The coil was replaced because it failed. Plugs and air filter needed to be repalced. Vacuum hoses brittle and cracked, falling apart. THe O2 sensor and fuel filter should have been replaced long ago. The OVP was the only thing I repalced that I probably should have done diagnostics on first. However for $58 (which got me over the free shipping threshold at Autohaus) I will live with it. Now I have a spare.

Now the good news. I did replace the alst vacuum hose; I did the seafoam thing, I did replace the fue filter and it was way better than before but still not perfect.

Cleaned again the ICV and lubricated with graphite powder. Still had some minor issues on hot start.

Checked the duty cycle at the diagnotic port and mine was like 85%! I did not know it had ever been adjusted, but it had been. I got it close to 50% now and problem solved. No more hesitation, bogging down, crashing idle speed, rough idle, fluctuating RPMS on hot start. Runs really well.

Still way cheaper than taking back to the shop.

If you want to check the duty cycle look at another post of mine about fluctuating RPMs on hot start. I got a lot of help on how to test it.
 

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1990 190e 2.6l Calif. auto 1987 Ford F150 4.9L Calif. man 4OD 4X4 2013 Suzuki C50 Crusier
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From my point of view of working on lots of cars in shops over lots of years and reading that thread I found me shaking my head alot at what was being done and for what reason. But sure if you are working on a problem and come across things that do need to be replaced I see no reason not to replace the part . And as for adjusting the duty cycle or lets say adjusting the carb. A NON TECH would look at the meter and see the readings out and then he would bring out the tools to start adjusting things. A Real Tech looks and sees the reading out and says to himself do I have a vacuum leak or something and looks for the problem. A computer sees the readings out and it also starts adjusting the mixture to correct the vacuum hose so the car runs better , but it did not fix the problem . ( the computer ) only covered the problem up, until the hose maybe breaks . Or maybe the air intake only needs cleaning. So dont jump right in and start turning things. So when you are reading here try to sort out the best way to find the problem ant to cover it up.
 
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