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1986 260E 124.026
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Discussion Starter · #1 · (Edited)
Hello!
I had a bunch of weird starting problems, bit rough running and extremely poor km/l (around 5-6km/l).
I bought this car for about 5 months ago, I bought it after it had been sitting still for 10 years. I am very close to the man I bought it from, and before I bought it we did some work on it, to make it pass it's inspection (which it did without any notice).
He does not remember much about the work he did on it himself.

My goal is to learn as much about cars and the KE-Jetronic system as possible, but while also having a nice functioning car. I gave up trying to figure out which was causing all the problems I had, as I got in way over my head. I found a man who claimed to have a lot of knowledge about the old Jetronic systems, and he said that he was willing to help me find my issue. He came by once and within 5 minutes said that my fuel distributor was shot. I then got it refurbished. Within a week I got it back and tested it like this:
Mount everything except for the 6 screws at the top, deflect the air meter plate while the key is turned to ignition.
Result: Bunch of fuel came out the top. SUCCESS

I mounted the 6 screws, turned the key and tried to start the car. It started at 500 rpm and died right away. I tried a bunch of things but nothing worked, it was just the same. I removed the 6 fuel lines from the top of the distributor again. Deflected the air meter plate (which was now very hard to do), turned the key to ignition, and no fuel came out, when the key was turned to ignition I could hear the return valve squeak, and I could feel in the meter plate that fuel was indeed getting in. I removed the line to the coldstart valve and fuel came out. Turned the ignition and it shot out fuel. I guess that is why it can start at 500rpm, but then does not receive any fuel to the cylinders.

I contacted the guy that refurbished my distributor and he said immediately that I should send it back to him. He called me back later and could not believe what I had explained. He told me that while he was waiting to get my distributor back, he would send me one that he knew to be working perfectly and I could test with that.
I received his distributor and the exact same thing happened. First try: It worked, all tries afterwards: nothing.

I realized that this might be the exact same issues that I had before, I just never got so technically into my problem.

If it is exactly the same issue then with my newly gained knowledge, the symptoms can be described as so:
If the car has sat for a long while 4+ hours (sometimes shorter and sometimes much much longer), starting it requires flooring the gas pedal and cranking for 30 seconds to 5 minutes (with pause to prevent the starter from overheating), when it successfully starts it runs very rough for upwards to a few minutes where the exhaust smells so bad and is so thick that you can't see out the windows as it engulfs the car. When warm the car accelerates great, runs quite fine, idles rough but not horrible, acts weird at low speed though, and without doubt has reduced power, but were not talking about a decrease at 50% or something, more like 10-15%

What I have done already:
Ignition plugs (non resistor), cables, rotor, distributor, distributor cap.
Fuel filter, OVP Relay

I'm scraping together the different parts required to measure fuel pressure, as I'm guessing this will tell me what my issue is, but any idea and help would be appreciated, and also if anyone has an idea of where to start the fuel pressure measurement.

Thank you.
 

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W124
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I would use the guy who rebuilt the fuel distributor as a technical support person. Ask him where he suggests you check pressures from. You don't want him to believe you did something wrong so get his advice so that your warranty with him stays intact.

In the meantime you need to chase down any vacuum leaks that the engine has. Forget getting help from the guy you bought the car from . Call me arrogant, call me cynical, call me what you want. But no one gets a car running just right and then lets it sit for 10 years. He either caused the problem you have, or hasn't found it yet.

An effective way to find vacuum leaks is to remove the air cleaner. Stretch a vinyl glove over the intake (where the airflow plate is). Use a wire tie to secure it around the neck of the housing. If you can, run a piece of duct tape from one side of the housing, over the glove, and down the other side of the housing so that the glove can't blow up with air. Next, attach a smoke producing machine to a large vacuum line. I like to use the one that connects to the brake booster. Then run smoke into the engine and look closely at all the places where it is leaking from. Each of those locations is a vacuum leak and needs to be tight. If you don't have a smoke machine (truth be told I don't), a nice cigar works fine. Take a good pull on the cigar and blow it into a hose attached to the vacuum line. After blowing the smoke in, put your thumb over the hose to hold the smoke in. You will notice the glove starting to "grow" as you add air pressure. Blow in three good pulls worth of smoke and you will have more than enough to see leaks if you have them. Fix those leaks while you are doing your fuel pressure tests. Good luck.
 
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Registered
1986 260E 124.026
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5 Posts
Discussion Starter · #3 · (Edited)
I would use the guy who rebuilt the fuel distributor as a technical support person. Ask him where he suggests you check pressures from. You don't want him to believe you did something wrong so get his advice so that your warranty with him stays intact.

In the meantime you need to chase down any vacuum leaks that the engine has. Forget getting help from the guy you bought the car from . Call me arrogant, call me cynical, call me what you want. But no one gets a car running just right and then lets it sit for 10 years. He either caused the problem you have, or hasn't found it yet.

An effective way to find vacuum leaks is to remove the air cleaner. Stretch a vinyl glove over the intake (where the airflow plate is). Use a wire tie to secure it around the neck of the housing. If you can, run a piece of duct tape from one side of the housing, over the glove, and down the other side of the housing so that the glove can't blow up with air. Next, attach a smoke producing machine to a large vacuum line. I like to use the one that connects to the brake booster. Then run smoke into the engine and look closely at all the places where it is leaking from. Each of those locations is a vacuum leak and needs to be tight. If you don't have a smoke machine (truth be told I don't), a nice cigar works fine. Take a good pull on the cigar and blow it into a hose attached to the vacuum line. After blowing the smoke in, put your thumb over the hose to hold the smoke in. You will notice the glove starting to "grow" as you add air pressure. Blow in three good pulls worth of smoke and you will have more than enough to see leaks if you have them. Fix those leaks while you are doing your fuel pressure tests. Good luck.
Thank you for your reply.
The guy that I bought the car from is my girlfriends dad, so he is not some dude that would try to cheat me into buying some crap that he knows nothing about. I got the car for a very good price for, he has already helped me alot and he says that he always will stand by too help me, if I need his tools or space to work. The explanation of why he had the car standing still for 10 years is that he loved fixing up old cars and selling them to collectors, both for the fun of it and for the earnings that he could get. He has 20+ old nice cars in his barns that sadly now has been neglected as he went from a full time employee to being now an all day all time only employee in his own very busy company, where he does all the machinery and service on his wind mills by himself. I always see the sadness in his eyes when he looks at the cars and tell me how he misses fixing them up.
I have a very tight budget and if I can’t scrap the parts together for a fuel preassure test (the sets I found are damn expensive), I will end up towing the car to the nearest mechanic to let them do the tests, they also have a smoke machine, and will let them run the smoke tests aswell. This will be a lot cheaper than a cigar and fuel pressure set. But of course i prefer doing it by myself, but it’s all down to costs now.
I will get back as soon as I know something new, and will still appreciate any ideas as to which part/parts is/are faulty
 

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Thank you for your reply.
The guy that I bought the car from is my girlfriends dad, so he is not some dude that would try to cheat me into buying some crap that he knows nothing about. I got the car for a very good price for, he has already helped me alot and he says that he always will stand by too help me, if I need his tools or space to work. The explanation of why he had the car standing still for 10 years is that he loved fixing up old cars and selling them to collectors, both for the fun of it and for the earnings that he could get. He has 20+ old nice cars in his barns that sadly now has been neglected as he went from a full time employee to being now an all day all time only employee in his own very busy company, where he does all the machinery and service on his wind mills by himself. I always see the sadness in his eyes when he looks at the cars and tell me how he misses fixing them up.
I have a very tight budget and if I can’t scrap the parts together for a fuel preassure test (the sets I found are damn expensive), I will end up towing the car to the nearest mechanic to let them do the tests, they also have a smoke machine, and will let them run the smoke tests aswell. This will be a lot cheaper than a cigar and fuel pressure set. But of course i prefer doing it by myself, but it’s all down to costs now.
I will get back as soon as I know something new, and will still appreciate any ideas as to which part/parts is/are faulty
first when you replace the fuel distributor , the mixture screw will need to be adjusted .buying a car that has been seating for 10 yrs with a CIS system is not a good idea .what is the fuel pressure ??? .when you say screws at top , you mean fuel lines .with fuel lines to injectors disconnected , no fuel will out .so when you get the car running the fuel mixture must be set .
.to test fuel pressure get a 100 or higher pressure gauge , a piece of descent gas hose , 2 clamps .you connected at the end of the line that goes to the cold start valve .you should read around 75psi .minor vacuum leaks will have little effect on this .this is not a DIY job !!!!
 

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Discussion Starter · #5 ·
first when you replace the fuel distributor , the mixture screw will need to be adjusted .buying a car that has been seating for 10 yrs with a CIS system is not a good idea .what is the fuel pressure ??? .when you say screws at top , you mean fuel lines .with fuel lines to injectors disconnected , no fuel will out .so when you get the car running the fuel mixture must be set .
.to test fuel pressure get a 100 or higher pressure gauge , a piece of descent gas hose , 2 clamps .you connected at the end of the line that goes to the cold start valve .you should read around 75psi .minor vacuum leaks will have little effect on this .this is not a DIY job !!!!
When you say that this is not a DIY job it just makes me want to do it myself even more. And I have gotten this far with no knowledge about cars a while ago. I love fixing problems :)
I am aware of the mixture screw which will be a problem of it’s time. The problem I have now is that no fuel comes out of the holes (holes for fuel lines) at the top of the distributor. I have acquired a verry accurate preassure gauge which goes to 180psi. The guy I bought the car from hopefully has the rest of the stuff I need, which he will give to me the comming days.
 

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When you say that this is not a DIY job it just makes me want to do it myself even more. And I have gotten this far with no knowledge about cars a while ago. I love fixing problems :)
I am aware of the mixture screw which will be a problem of it’s time. The problem I have now is that no fuel comes out of the holes (holes for fuel lines) at the top of the distributor. I have acquired a verry accurate preassure gauge which goes to 180psi. The
When you say that this is not a DIY job it just makes me want to do it myself even more. And I have gotten this far with no knowledge about cars a while ago. I love fixing problems :)
I am aware of the mixture screw which will be a problem of it’s time. The problem I have now is that no fuel comes out of the holes (holes for fuel lines) at the top of the distributor. I have acquired a verry accurate preassure gauge which goes to 180psi. The guy I bought the car from hopefully has the rest of the stuff I need, which he will give to me the comming days.
When you say that this is not a DIY job it just makes me want to do it myself even more. And I have gotten this far with no knowledge about cars a while ago. I love fixing problems :)
I am aware of the mixture screw which will be a problem of it’s time. The problem I have now is that no fuel comes out of the holes (holes for fuel lines) at the top of the distributor. I have acquired a verry accurate preassure gauge which goes to 180psi. The guy I bought the car from hopefully has the rest of the stuff I need, which he will give to me the comming days.
learn how this system work , used manuals on ebay .Now, that you have a gauge , what have you done with it .with injectors of , you will have zero fuel coming out .the fuel distributor need to see pressure in the injectors lines .so no injectors , no pressure , no fuel coming out .today with you tube , there is no reason to not know .i will stay away from this subject .
,
 

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Discussion Starter · #7 ·
So my update now is that I need to move the car, I have a few options:
If my problem now is the same as it always has been I should be able to start it and drive it, if I crank long enough, which I have already planned to try, to see if it actually can start, and therefor confirm that my problem is the same, but I'm not happy with cranking for so long, as it definitely shortens the life of the starter, does anyone have any tips to try this? How can I keep the starter cool while pushing it so hard?
I can tow the car (I have to tow it for quite a distance)
I might be able to do the work where is is now, but I will be at a risk when jacking the car up.
 

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So my update now is that I need to move the car, I have a few options:
If my problem now is the same as it always has been I should be able to start it and drive it, if I crank long enough, which I have already planned to try, to see if it actually can start, and therefor confirm that my problem is the same, but I'm not happy with cranking for so long, as it definitely shortens the life of the starter, does anyone have any tips to try this? How can I keep the starter cool while pushing it so hard?
I can tow the car (I have to tow it for quite a distance)
I might be able to do the work where is is now, but I will be at a risk when jacking the car up.
if it is like a us model , it has a voltage protection relay , behind battery , it has a red cap on top with a fuse in it .when you jump start car , the fuse can blow , so look at this .also get a can of starting fluid , and see if it start right away .if it does , then you have no issue with ignition system .
 

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Discussion Starter · #9 ·
if it is like a us model , it has a voltage protection relay , behind battery , it has a red cap on top with a fuse in it .when you jump start car , the fuse can blow , so look at this .also get a can of starting fluid , and see if it start right away .if it does , then you have no issue with ignition system .
I have tried with starting fluid, and if I give it some it only lives on that because as of right now the problem is not ignition, but simply that the engine does not get fuel. I’m not jump starting the car. The OVP relay is new as listed on parts i changed.
 

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I have tried with starting fluid, and if I give it some it only lives on that because as of right now the problem is not ignition, but simply that the engine does not get fuel. I’m not jump starting the car. The OVP relay is new as listed on parts i changed.
if you have someone crank the car for you , and you under the hood , while it s cranking push on the air flap down , and see if car start and keep running while pushing air flap down some . the other way , is have fuel pump running [ jump the 2 wires at fuel pump relay plug , ] now push on the air flap , does injectors start making noise , if so , how far do you have to push .the injectors should start when plate is depressed by a small amount like a couple of mm .if that dimension is too large , turn the 3 mm mixture screw clockwise to achieve that 2 mm , more or less .when you crank the engine and watch that air flow plate , it goes down a little , at that point the injectors come on .if they dont , it wont start . also , what is the basic fuel pressure at the end of cold start valve .
 
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