190Efan

This certainly has been an unusual one. I've had a suspicion that too much fuel was happening which was actually flooding the car and that would make the car hard to start. There are a number of culprits that could be causing that to happen. I'll be curious to see what the ECU test results are as well. I think Dolucassi's theory that the CSV is continuously spraying fuel into the system which is then flooding the car hat the ECU is then compensating for which is then making the car hard to start is a good one. You need to rule out the ECU first to be able to determine if the CSV is in fact the culprit. If the ECU checks out ok and you replace the CSV and the car starts properly, then the problem will be solved. Dare I ask what's wrong with the A/C?

dolucasi

The car has been neglected and non-running when purchased. As I mentioned in one of the early posts, there are probably multiple issues under the hood.
Since there is a cause and effect (sign) on the CSV, it is a good place to start. Certainly not acceptable to just leave it unplugged because the car seems to idle better.
Without the cold start valve it will be rather difficult to start the car without it in cold weather.

Hopefully rufrob will come back with some measurements at the X11 ports 3-2 and CSV voltage as this and other issues will be like peeling the layer of the onion.

- Cheers!

190Efan

I totally agree with you. The measurements you've suggested are the next logical step since it looks like the easier, more obvious possibilities have been ruled out for now. It's really tough to diagnose a car that you have no idea what the previous maintenance history is. That's why I've suggested starting with the easy more obvious possibilities and then working up the food chain to the more complicated possibilities. Hopefully the OP will continue to post his findings and we can help finally figure out the real issue. I'm also of the opinion that this particular W201 likely has multiple issues all going on at the same time.

rufrob

I had a long day and was too exhausted and cold the deal with it last night.
The PO a dealer took it as a trade in, got it running and sold it at auction. The buyer returned it saying it had no compression in#3. So instead of basically giving away the car which they would have to do according to auction rules they gave it to me to fix. I have a reputation of repairing impossible projects: blown engine on a Lancia Delta Integrale, coolant pipes on a 996 Turbo, Corvette C4 abandoned show car and more. All in my driveway while the dealer has a fully staffed 6 bay facility. First is delivered it to me asking me to fix it so he could try to sell it again at auction. So we negotiated a price and I bought it.
That's the background. I have restored 928s from half an engine which has taken less time to figure out than this car.
First the auxiliary fan stayed on, occasionally it started them stalled. Found out they only washed the fuel tank and the rust came back. The filter was plugged the FPR was leaking the FD was dirty and had deteriorated diaphragm, the sensor plate wasn't centered and was binding. They underside was all gummy hence the plunger couldn't move freely.
Today I'm "working from home" so I'll test the computer.

rufrob

I took it to a nearby specialist. In 5 mins he tells me no signal from the potentiometer.
Called the dealer and he cant find the pn. All I find online is 3437224035. This pn comes up an error on his system.
Is there another pn for this air flow potentiometer?

190Efan

I'd suspected that the fuel system had to have some pretty serious plugging issues. I'm glad they've now all be addressed. I would also suggest that you check the condition of the spark plugs. They probably should be replaced as well. As for the correct part number for the potentiometer, you might try contacting the MB Classic Center in Germany. They should be able to tell you the correct part number. The 2.5-16v was never sold in North America so it's unlikely that the MB Classic Center in California would have that part number.

dolucasi

It is rather unusual to have an AFM pot go bad at that low of mileage. It is possible but unusual. Mine is still the original at 205K miles. It is worn but not ready to be replaced.
I would want to make sure it is the only culprit here. You can actually test that without going to too much trouble but needs basic electrical knowledge.

I wonder if contamination got to it. How clean is your throttle body/AFM plate area?

Remember that contrary to common belief, AFM pot hardly does anything after the engine reaches operating temp. Does plenty during the first minute of warm up.
After that, super bad signalling (opens and shorts) could effect running of course. If you have idle issues you can just connect a fixed resistor divider on the connector after unplugging it. The car should run fine warm with this divider AFTER it warms up because the ECU pretty much ignores the signal as long as it is within range. The ECU will not like an OPEN or a Short on pin 2 of course.

It is an expensive item from BOSCH (like $250) and is nothing more than an expensive slot car controller. And if you decide to buy one, do not buy anything but the BOSCH unit. You will regret it.

The expected voltage range on pin2 is 0.6V (idle) to about 4V (near open throttle), that is because there is a voltage divider between pin3 (power source from the ECU of a consant 5V) and pin1 (ground). It could be the other way around, I will have to look at the schematics.
Pin 2 is your signal. With AFM closed it will be approximately 0.6V in idle.

It is also possible you do not have 5V coming from the ECU. In that case it is not you AFM pot, it is the ECU or wiring that is the culprit.

With these cars you need a multimeter and only a little bit of the KE-JET knowledge. Hopefully the specialist you took the car to has a deep understanding of the system. There are very few mechanics left around who know the system these days it seems.

- Cheers!

190Efan

You also might go to You tube and check out Pierre Hedary's videos on the KE-Jetronic fuel system. He owns a repair shop and specializes in the 190E. He won't probably be familiar with the 2.5-16 since he's in the U.S. but his basic knowledge of the fuel system might be a help for you.

rufrob

Thanks.
Remember I'm in Japan and the Japanese dealer couldn't find the part. I'll remove it and take it to them tomorrow. Weird that even with the CSV removed the car still high idled then normalized then stalled. The specialist knew it was rich so he leaned it out.
On the short drive it had.no power

dolucasi

Hopefully removing the AFM pot is a lot easier on a 16V than on a 2.6L. It is not something you do on a whim on a 2.6L.
Not entirely clear why you need to remove it to show to them. Yes you will see some marks on it and yes that is to be expected.

You seriously are in need of a multimeter to be honest, IMHO.
The AFM pot is just tested with an ohmmeter while still in the car. It can not be tested outside the car.
One just attaches a ohmmeter from pin 1 to pin 2 and measures resistance while you do an AFM sweep.

Has the specialist done this? No power to the AFM pot is not the AFM pot's fault. Maybe something got lost in translation here from Japanese to English though.
Power to the Pot means the regulated supply voltage delivered by the ECU to the Pot. If that is measuring zero that means either the ECU or the wiring is at fault.

- Cheers!

rufrob

I do have a multimeter but I'm the first to admit electronics is my weak point. I tried understanding it but gave up all too quickly.
I have done almost everything in cars except opened a transmission and got into electronics.
It's a PITA to remove the TPS but shouldn't take me more than 15mins.
The harness looks to be in very good condition. But I'll check it all again. $200 is not little money considering how much I've put into this little car already.
It had other issues too.
I best paint it get it running and sell it.
The specialist told me the PO uses 744 and not the proper 735u and that the cladding should be flat not shiny. So a full respray is necessary.
Sorry guys but my W210 AMG has one my heart and a forever place in my garage.
It carried a 944 engine and engine hoist like it was no biggie. The SLS couldn't completely raise the rear but it never bottomed out.

dolucasi

Yeah, unfortunately I have a feeling you have been replacing parts unnecessarily in the past 'm afraid.
Would you believe that all my emissions components with the exception of obvious wear items: Oxygen Sensor, Spark plugs, distributor cap and rotor and OVP, are all original at 204K miles and 33 years. I did mess up the IACV thinking it was a stall issue, but that was my bad, it turned out to be the OVP. The replacement IACV from a JY is still in the car and doing just fine. So I would consider that original too.
All the components were built to last at least in relatively mild California Weather.

I doubt there is anything seriously wrong with your AFM pot. But if you can not test it with an ohmmeter, I'm not sure how I can help you.
Just make sure the mechanic really did mean "no power to the AFM pot" and not "no signal from the AFM pot"
Those two are entirely two different issues.

Also, the mechanic fiddling with the lambda alignment screw right off the bat without diagnosing your problems is a very bad sign, you should question his judgement.

- Cheers!

rufrob

Between 2 and 3 3.57v ignition on. Up to 7.10 at cold start. Stays at 7.06 after stall.

rufrob

Reconnected the CSV and it high idled them came down to about 800 and stayed.

190Efan

The MB Classic Center is only an email away. You might also want to let them know the issues you're having with your car and see what suggestions they might have. It was a very bad mistake for your mechanic to lean out your car without determining the cause of the high idle. These cars really aren't supposed to be adjusted blindly like that so that's a big red flag about your mechanic. You need to be working with someone who has years of experience with 190Es. It's pretty clear that your car has suffered from years of serious neglect and it's going to take some real expertise with this model to help you get it running again. These are great cars and provide years of flawless service when they've been properly maintained. I know from personal experience of owning them for more than 30 years..

dolucasi

So the duty cycle measurement are relative measurements not absolute. It is relative to the system voltage at any given time.
With the ignition on engine off, most batteries are healty and supply 12.5-12.6 Volts. Yours appears to be 11.9-12.0 volts.
Please check that and repeat these measurements in pairs:
Pin 3-2 voltage and System voltage (I think that might be 6-2 or 4-2, please check)

So the above measurements need to be repeated and we need 3 pairs of numbers. Your last one after Stall does not make sense as the system voltage would have gone back down below 13V rather quickly.

With the incomplete numbers you presented, I'm guessing there is no error code presented there, but let's make sure.

Please post your findings with measurements which will help us help you.

- Cheers!

dolucasi

Ok, so your CSV does not appear to be effecting things as it should not. I'm assuming the earlier experience was some sort of glitch, or in the process of disconnecting the CSV you may have jostled the EHA connection which maybe suspect at this point too.

Keep feeding us the measurements on your post, we can resolve your issues across the large pond. It may take a bit but we will get there. And the process you will also learn the KE-JET system.
It is not rocket science, believe me. For most owners the singe gauge in this post below will tell you 95% of the health of your cars emission system, real time. So you would not be in the dark as to what the heck is going on. This comment is not necessarily to you but to all the other listeners out there.

https://mbworld.org/forums/190e-w201...installed.html

- Cheers!

rufrob

Thanks. I didn't have much time last night so I'll try to read again on the KE Jetronic system.
Last night when I inserted the probes to check for power at all the ports, I heard clicks and other noises I never heard before from the right side of the engine bay.
I'll cold start it again tonight.

rufrob

3 tries before it stayed running. That's progress in my book. Quick drive and it had more power. Not anywhere where it should be. Ii moved the potentiometer and got some change on the volt meter
Idle is still high but starts easily when hot. Below are the multimeter reading at ignition on and engine on

dolucasi

Hi Rufrob, thanks for the pic's but not very helpful at all. Also for long distance diagnosis to work, you need to measure and change things one at a time. That is engineering-101.
Please read post #41 again.

I will need the following before you change anything else on the car. I have a hunch I know what is going on but I do not want you to jump around and fiddle with things before I have these readings.

Your system voltage (pretty much the battery voltage past the fuse on the OVP is pin6 to pin2 of that X11 diagnostic socket.

Pictures of the multimeter are not of that much help, so instead list these:

engine cold:
Iginition On, Engine Off = pin6 - pin2 voltage, pin3 - pin2 voltage
Ignition on, Engine running = pin6 - pin2 voltage, pin3 - pin2 voltage, idle speed immediately after start (maybe 5 seconds after it starts), vacuum gauge in the car (a photo of this would be helpful)

Engine hot/operating temp:
IgnitionOn, Engine Off = pin6 - pin2 voltage, pin3 - pin2 voltage
Ignition on, Engine running = pin6 - pin2 voltage, pin3 - pin2 voltage, idle speed, vacuum gauge in the car (again a second photo of this would be helpful)

So if you can complete this table table above, I can help you, otherwise not much I can do from 10K miles away.

- Cheers!

rufrob

Yesterday was crazy busy. There was precious little time for playing with the car.
Thank you very much for the instructions. Please give me the reading ranges I should expect.

rufrob

Cold
Pin 6-2=11.91
Pin 3-2=3.61
Engine running cold
pin 6-2=13.72
Pin 3-2=8.25
Engine running hot
Pin 6-2= 13.89
Pin 3-2= 8.32

dolucasi

Cold
Pin 6-2=11.91
Pin 3-2=3.61
Expected value is 70% (for a non-Califorina Car) - yours is 100% - (3.61/11.91)*100% = 69.7% - Check, no problem here
You have a weak battery, so you should get that checked. I would say 12.2 is the lowest it should be. Or it needs to get charged. Maybe the long cranks drained it.

Engine running cold
pin 6-2=13.72
Pin 3-2=8.25
Expected value is 50% (no error codes) - yours is 100% - (8.25/13.72)*100% = ~40%. This is an error code. Read up on the error code table and find out what this is.

Engine running hot
Pin 6-2= 13.89
Pin 3-2= 8.32
Expected value is 47% +/-5% and fluctuating (cycling another +/-5% or so) = Your reading is 100% - (8.32/13.89)*100% = 40.1%. If this is not fluctuating (which I believe is the case) the ECU is still telling you there is an error code and the closed loop emission system is not working at all

Under these circumstances it is inconceivable that the specialist tried to adjust your lambda. He does not know this system. He must have adjusted it blindly which is very bad.

Verify that when hot the voltage on Pin3-2 is static and not moving constantly, up or down, between something like 7.7V and 8.8V every 2 seconds. If it is static emission control is kaput.
Also rev the engine to 2500 rpm and read the last numbers again, but this time give me both numbers one more time (idle and 2500 rpm). So again, I need 4 numbers.
Pin 6-2 at idle right before you rev the engine
Pin 3-2 at idle right before you rev the engine
Pin 6-2 at 2500rpm, hold it there for 10 seconds before you take these measurements
Pin 3-2 at 2500rpm, hold it there for 10 seconds before you take these measurements

Also do an internet search and tell us what 40% static error code is, it is all over the internet.

- Cheers!

dolucasi

I did the search for you. 40% is false output from AFM POT.
So the specialist diagnosis was indeed lost in translation. It was not false power to POT it was false signal from POT. This is good and the specialist is vindicated.

So now we will use the multimeter to check the POT to make sure the problem is not in the wiring but the POT itself.
For this you will measure resistance (ohms) in your DMM.
Remove the air filter assembly
You will unplug the POT connector at the AFM POT. On the pot side you will see 3 pins, labelled 1-2-3.
You will measure the resistance between pin 3 and pin 1. Report this
You will measure the resistance between pin 1 and pin 2. Report this
Expected value is somewhere between 1K-2K ohms.
You will slowly push down on the AFM plate as you are measuring pin1 to pin 2 resistance and see how the resistance changes. It should slowly go up in value from 1-2Kohms as high as 8K-10K ohms and towards the end it will drop down slightly to 6-7K ohms.
There should not be major discontinuities in the resistance, if there is the AFM pot is worn. But remember, a car at this age will be less than perfect and a minor discontinuity will not trigger an error code or cause any running issues that you will not even notice because AFM signal is predominantly used in the first minute or so when the engine is warming up. Otherwise it is mainly ignored other than for Wide Open Throttle.

I suspect your AFM pot is just fine but there is a discontinuity somewhere, but report on all your findings.

rufrob

Thank you so very much.
I got my 3rd shot yesterday. Last night when I checked the car I was ok. But early in the morning and now the side effects are hitting me hard. Chills, muscle pain, headache fatigue.
I didn't loose my appetite though. It's a nice day here today too. I'll take a nap a see how I feel later.
Thanks again.
I hope I've helped others on other Porsche and Benz forums