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I tested the altitude sensor tonight. It was a little of pain but he is what I got.
3 wires/
brown
blue (2 wires)
blue- red
4.87v between brown and blue. Supply voltage I think
3.54V between brown and blue/red. Signal voltage. Read somewhere signal voltage of 4 V at sea level, 3V at 1000m and 2V at 2000m.
I am at 1600 feet or 500m so 3.54V seems correct.
On the temp sending unit, it need help. I tested the two wire sensor in the back of the picture, read 6 Kohms. There is a 3 wire in the front but I am afraid of breaking the connector. I will test if that is the one but I need a little help on testing procedure. Thank you.
Yeah, with al this trouble there should be some CEL codes in there. Also you did not respond to my other question (or did I forget to ask it), does your CEL warning light work?
It should come on with ignition on, engine off, and then go dark.
If none of this is operating, that maybe another sign your ECU is sick (not completely dead, just sick)
I don’t seem to have a CEL. Have an o2 sensor light. O2 light comes on with ignition on engine off.
190E 2.6L 1989, 190E 2.6L 1988, BMW 535dXdrive 2014, BMW 428i 2015
Originally Posted by jfmeull
I tested the altitude sensor tonight. It was a little of pain but he is what I got.
3 wires/
brown
blue (2 wires)
blue- red
4.87v between brown and blue. Supply voltage I think
3.54V between brown and blue/red. Signal voltage. Read somewhere signal voltage of 4 V at sea level, 3V at 1000m and 2V at 2000m.
I am at 1600 feet or 500m so 3.54V seems correct.
seems to check out.
Yep, this all looks normal. Not sure if you tried to unplug it to see if it triggers your O2 light but probably not needed at this point.
190E 2.6L 1989, 190E 2.6L 1988, BMW 535dXdrive 2014, BMW 428i 2015
Originally Posted by jfmeull
I don’t seem to have a CEL. Have an o2 sensor light. O2 light comes on with ignition on engine off.
I think Mercedes just changed terminology after your year of manufacture. I'm guessing 02 = CEL at this point.
I'm not familiar with the mess of sensors in your engine but I have a hunch you have one of the earlier 3 prong temp sensors.
One pin is common reference, the one of the other 2 goes to your cluster and the other goes to your ECU. So find the 3 prong one and check that the resistances to the reference are the same and the numbers are same as I mentioned, ~200ohm at operating temp and more like 2-3K when cold.
This is just a check. I will be surprised this is your issue.
After that do unplug your ECU with a warm engine with the key not in the ignition switch. And tell us what happens when you start the engine and rev it, and even drive it.
Weather has been bad so I have not been able to test the car without the ecu. However I tested the 3 prong temp sending unit and I have no continuity between any of the pins (OL). I am ordering one of these.
Weather has been bad so I have not been able to test the car without the ecu. However I tested the 3 prong temp sending unit and I have no continuity between any of the pins (OL). I am ordering one of these.
I figured that the no check engine light was a clue. I'm glad that you have now likely found the problem.
190E 2.6L 1989, 190E 2.6L 1988, BMW 535dXdrive 2014, BMW 428i 2015
Originally Posted by jfmeull
Weather has been bad so I have not been able to test the car without the ecu. However I tested the 3 prong temp sending unit and I have no continuity between any of the pins (OL). I am ordering one of these.
Hmmm. Is your temp gauge on your cluster working? If you had an open temp sensor the gauge would not work either and would show cold temp all the time.
Are you sure you are measuring the temp sensor and not some sort of switch?
Now if there was an open certainly the ECU would act strangely, that is for sure but that in itself should throw a code, but then again I think you ECU may be damaged.
So I just found this in a supplemental service manual for the 2.3 16v. Looks like the sender unit is not what I tested. To answer your question, the coolant temperature is reading fine inside the car. I also discovered in the same publication that current at the eha with ignition on is supposed to be 50mA which is what I reported earlier for my car. It looks like what is connect to the ecu is a 2 wire sensor. I have not checked that.
I did the ecu test tonight. Warmed up the car 80c, turned the car off, removed the ecu. The car starts fine but the issues persist. Idle at 1000 without ecu, pressing on pedal gradually, the car sounds good up to 2500rpm, after that it dies off and rpm decreases to 1500rpm backfiring and sputtering. WOT and the rpm’s don’t go past 1200-1400 rpm, sputtering. Not sure if this better or worse news. Anxious to hear thoughts. JF
190E 2.6L 1989, 190E 2.6L 1988, BMW 535dXdrive 2014, BMW 428i 2015
Originally Posted by jfmeull
On reading codes you mentioned a good video but I can’t find it. Could you help me find it?
Looks like Kent Bergsma now charges $4 for this on demand video. It used to be free. But it covers '88-'95 only.
Does your car even have the OBD-1 capability? I thought yours was an '87. Not sure why an '87 is not covered.
Thank you for looking this up. My 87 has the round 9 pin plug. I found a table of codes that covers various versions of the KE jetronic. It does not seem to cover my car. It will do a little more research but the blinking led method probably won’t work.
I measured fuel pressure to be 5.5 and 5.1 bars. The supplemental service manual states that pressure for this engine was increased to 5.8 bars so my car reads low and I am not sure how much of an issue that is. The pumps, accumulator and filter were installed new by the previous owner.
It does now sound like you've also got a fuel issue too. I was always taught to start with the easiest and least expensive things first. Stating the totally obvious, have you checked the fuel filter and fuel lines to make sure that they're clear? Once you know that these are clear, then you can move on to another obvious check which is to make sure that you hear the fuel pump working.
It does now sound like you've also got a fuel issue too. I was always taught to start with the easiest and least expensive things first. Stating the totally obvious, have you checked the fuel filter and fuel lines to make sure that they're clear? Once you know that these are clear, then you can move on to another obvious check which is to make sure that you hear the fuel pump working.
Can you recommend some specific procedure to check the fuel line and filter? For example, should I measure the fuel pressure at the end of the fuel line while bridging the fuel relay? The fuel filter is new but I did not install it. The car does start and runs...just poorly so I assume the new fuel pump works...right?
190E 2.6L 1989, 190E 2.6L 1988, BMW 535dXdrive 2014, BMW 428i 2015
Indeed your model appears to be pre-OBD1. That's to bad, makes things a bit harder but it certainly explains a few things. Like the missing CEL light.
I'm still stuck on this cold running EHA current. That is not correct and certainly the ECU is not putting out the correct current in open loop running condition.
So the culprit there would be Altimeter (checked already), coolant temp (still under Diagnosis)
Let us first vindicate the coolant temp sensor. And make sure you are getting the same value for the cluster sensor as well as the ECU sensor from cold to hot and post the results here.
The fuel pressures seem correct to me. My pressures have always been the same 5.5Bar over 5.1Bar. I think that is normal.
Can you recommend some specific procedure to check the fuel line and filter? For example, should I measure the fuel pressure at the end of the fuel line while bridging the fuel relay? The fuel filter is new but I did not install it. The car does start and runs...just poorly so I assume the new fuel pump works...right?
Just take the fuel filter out and have a look at it to make sure it's not clogged with debris. Same for the fuel lines. I do agree with Dolucassi to verify the status of the temp sensor first.
Indeed your model appears to be pre-OBD1. That's to bad, makes things a bit harder but it certainly explains a few things. Like the missing CEL light.
I'm still stuck on this cold running EHA current. That is not correct and certainly the ECU is not putting out the correct current in open loop running condition.
So the culprit there would be Altimeter (checked already), coolant temp (still under Diagnosis)
Let us first vindicate the coolant temp sensor. And make sure you are getting the same value for the cluster sensor as well as the ECU sensor from cold to hot and post the results here.
The fuel pressures seem correct to me. My pressures have always been the same 5.5Bar over 5.1Bar. I think that is normal.
I tested the temperature since it is a lot easier than messing with the fuel filter 😁. I finally figured out how to test resistance on this sensor. Although it has two poles, it is two single pole sensors in one body. One to the ecu, the other to the ezl. I tested from the pole going to the ecu to the battery ground.
ambient temperature, about 2900 ohms and at 80c 190 ohms. Seems to be working. While I was at it, I also checked continuity between that wire and the pin on the ecu connector plug. I have continuity. The sensor to the gauge is another single pole sensor in the same area. When I disconnect it, the gauge goes to zero. I had problems reading resistance. It read zero but depending on where I tested on the pole, I had some signal but not stable. Since the gauge is reading, I think we are ok.
I am not looking forward to taking the filter off but I guess I will do that tomorrow.
I also read this tonight in the supplement manual I spoke about. The FOM may explain the duty cycle value we we reading earlier? Also addresses the O2 light. Not sure what malfunction means but I will try to figure out how it is triggered.
190E 2.6L 1989, 190E 2.6L 1988, BMW 535dXdrive 2014, BMW 428i 2015
I think your temp sensor is also vindicated with those measurements.
It is true that if the ECU receives illogical or out of range signals it will revert to a pre-set value for EHA current and idle.
In your case since we have checked out every sensor we could think off, that leaves the wiring to the ECU or the ECU as the culprit.
You may want to look up the pin connections to the ECU and check for sensor readings (temp, altimeter, etc) at the ECU end but unplugging the connector.
If those readings also check out on the ECU side, then I'm afraid your ECU may have gone bad. This only relates to your cold running incorrect EHA current readings.
I think you need to tackle the cold running first. And that may fix your other running issues too.
I decided to do a fuel quantity test out of each of the injectors. Not good! I jumped the fuel pump relay at 30 and 87. Ignition on. Injector 2 was dripping without deflecting the air flap. Injector 1 gets twice as much fuel as 3 and 4. What is the advice the group would have.
190E 2.6L 1989, 190E 2.6L 1988, BMW 535dXdrive 2014, BMW 428i 2015
Well, this could be your injectors or the FD. Not sure if there is a way to test that without replacing the injectors. One thing you can do is shuffle the injectors and see if the problem moves with the injectors. If not, than the FD has an issue, if it moves with the injectors, I would try a new set.
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