Bringing back 280CE w114 to life

[Niko9]

Hi Everyone,

as some of you are aware I am currently trying to bring back to life my w114 280CE EURO M110. I will share some of my experiences in last couple of weeks. I am currently having a problem where car stalls when getting warm (minute or two)


Initially when I purchased a vehicle it would only start and die within seconds, engine did not sound good and all ignition wiring was messed up.

Ignition

I had a complete mess in terms of wiring, one red with black wire which was 12 volts and another red with pink, I ordered my electric ignition kit with coil (with ballast resistor as my previous setup had this)


RED AND BLACK wire is going + and - (red plus black minus) ignition wire with another one is going to the end side of the resistor (so resistor is connected to + and you connect wires to opposite


I decided to remove distributor and everything all-together to clean parts - this was my first mistake, I did not make any notes as how the wires were connected, nor I understood firing order correctly. if this was not enough I did not make any marks as where the engine was.


In my Instance the TDC was not when the cylinder is at the top (i put a stick and manually cranked the engine but where there are two 0.0

Firing order on the rocker cover is very straightforward but as I was reading between lines I made mistake where I thought 1-5-3-6-2-4 is just numbers assigned to a cylinder, so for this purpose second lead should be treated as 5th.. (dont ask.. i dont know)

always make a note where there is a thin line not on a plastic cap but on an actual distributor housing, that indicates where the first lead should go to..



I bought new leads and changed sparkplugs, turned the keys and car started... it was one of the best feelings, it would run well, the white smoke was coming from the exhaust and when I pressed the gas black smoke would come out..

I figured out that i needed a timing light and to adjust throttle position sensor and all of this should be good.





I also adjusted clearance on camshafts (intake 10 mm/exhaust 25mm)
PROBLEMS BEGUN


Car was running OKish, it would hold idle, sometimes it seemed that it would die but it was not at the end. I decided to check oil level, it seemed to be a bit low, I went to the shop bought 20/50 and drained a plug.. surprisingly a very little oil came out, I did not have a proper jar to measure but it should not have been more than 2 litres, I added 5 litres, put a car back and started it..

it was running extremely poorly, the fan-belt would squeak and when i opened oil cap smoke was coming out.

I was aware that head gasket should be replaced (there was a spare one in the boot.. but now it shocked me.. I am not sure what it can be as oil change does not seem like a reason for this..

One thing I realised is that oil pressure before was 30 when car was idling, now as soon as it starts its 45 and does not drop.

I opened sparkplugs and they are not wet but very black
What have I done so far

1. Electric ignition - works, car was running
2. Sparkplugs - are dark
3. Leads
4. Camshaft adjustment
5. Steering fluid
6. Breaks

Checks
MAP sensor - checked connections, did not check vacuum its fine.
Compression in cylinders (car was warmed up for minute or two )

Compression PSI

1. 1 135
2. 2 140
3. 3.138
4. 4.145
5. 5.150
6. 6.155

I am planning on checking fuel system as CTH 350 advised me thank you again for being my teacher.

I tried to check injectors but its hard to understand vibration when engine is running roughly, is there any other was I can check injectors?
how do I check fuel pressure? Charles explained that I need to plumb it instead of cold start injector, `i am not even sure which one it is..

if you have any idea what checks I should perform and what else can it be please let me know..

also I would be changing head gasket in following days, I am currently researching 'how to ' guides

[cth350]

Niko and I have been exchanging private messages about the car. He's gotten his wiring issues addressed. Anybody have a picture of where the cold start valve is for him? I don't have an EFI M110 handy.

I have pointed him to ebay auctions for the various paper manuals he needs for this car.

@Niko, your numbers for valve clearance are missing decimal places (25mm is a really, really big gap).

-CTH

[meltedpanda]

CTH , you may have addressed this
if your plugs are dark you are getting too much air or too much fuel and most likely both. Look for vacuum leaks . If the injectors are original , just change them out, they could be the culprit , leaking and or bad spray patterns . Then work with your timing , do that by ear to start by moving distributor slightly until you hear the engine smooth out.

[Niko9]

Hi Charles, Metledpanda,

Thank you very much for your reaponse, as in for valve clearence, ive adjusted to 0.10mm and 0.25mm.. (punctuation has never been my strongest skill ��)

As per CTH recomendation ive pulled out cold start valve and checked for fuel pressure which is low 1.9 bar - it is meant to be 2.1.

Ive tried asjusting it with the screw on fuel distributor but whether i rotate clockwise or anti clockwise the pressure stays the same.

At the present id like to know whether my problems are fuel related, and if its only a fuel distributor which is faulty.

I checked the fuel pump and it seems to be a new unit, i am curious whether there js a test which i can perform to see whether its functionality is up for a standard required.



One thing that puzzles me is how before oil change car idled and after oil change it cant hold an idle?!

[cth350]

The fuel pump test is two parts...
1. Ensure you are getting the right pressure.
2. Ensure that you get at least a certain volume of fuel in a fixed period of time (not that I remember what that volume is).

Yes another source of pressure loss is an injector stuck open, thus my suggestion of using a mechanic's stethoscope to listen to each injector to see if they are clacking away. If you don't have one handy, a long screw driver works fine too.

Either way, you touch one end to the injector body and the other end to your ear and you'll pick up the distinct vibration of the solenoid in the injector.

-CTH

[Frank Reiner]

Originally Posted by Niko9

Ive tried asjusting it with the screw on fuel distributor but whether i rotate clockwise or anti clockwise the pressure stays the same.
At the present id like to know whether my problems are fuel related, and if its only a fuel distributor which is faulty.

Originally Posted by rumb

"Ive tried asjusting it with the screw on fuel distributor but whether i rotate clockwise or anti clockwise the pressure stays the same."
That is not what that screw does!!!!!
Please get a manual and read it before you randomly turn screws your shouldnt. The FD screw is the LAST thing you touch and even then even 1/8th of a turn is a lot. turn it too much and loose track and you will never get your car running.
Sorry to be harsh but that is the truth.

The fuel injection system in question is D-Jetronic. D-Jet does not have a fuel distributor; it is electronic, and has individual solenoid injection valves. Analyses and adjustment advice that apply to K-Jetromic (CIS) are, um, difficult to apply to D-Jet!

[Niko9]

CTH350,

I have connected fuel pressure gauge instead of cold idle injector, the reading says 1.9 bar and stays the same. For a significant period of time.
I have checked injectors as you advised, each one of them seem to vibrate through long screwdriver so that is ok i guess

Rumb,

I have several manuals, including a software which shows me almost everymodel but unfortunately d jeteonic CE version is not present. Hence i use websites such are d jetronic.org.

Most of the time they talk about what to do if the fuel pressure is high, often there is a mention of screwing in and out a screw on fuel pressure regulator
https://classicmercedesparts.co.uk/products/20357-mercedes-benz-w114-280ce-coupe-fuel-pressure-regulator-0280161001?currency=GBP&variant=39553196884099&utm_medium=cpc&utm_source=google&utm_campaign=Google%20Shopping&gclid=EAIaIQobChMI47G8yszA9AIVke7tCh3eTgH0EAQYASABEgK2bvD_BwE

Frank Rainer

When i screw in and unscrew fuel pressure regulators (one above and one underneath the air intake pressure does not change in the gauge which is connected instead of cold start injector, it stays at 1.9 bar.


Cold start is good, (without vacuum hose from distrivutor to intake) with the vacuum you can feel rpms dropping down.

After a while it geels like it has a loss of power and idle slowly dies whilst engine is shaking.


Just to sum up.

I have tried to adjust both fuel pressure regulators - no result
I have rested injectors ( all of them seem to vibrate whilst engine is running


Car dies after a minute or two whilst slowly loosing power. The odd part is that this happened after changing oil, when you remove an oil cap you can see a white smoke, i am crrtain that i have to change head gasket but first i would like to make shre that the car idles and does not shut off like it used to before.

My apologies for using wrong terminology and causing confusion

[Frank Reiner]

Niko:
Here are two quotes from your last post:

"When i screw in and unscrew fuel pressure regulators (one above and one underneath the air intake pressure does not change in the gauge which is connected instead of cold start injector, it stays at 1.9 bar."

"I have tried to adjust both fuel pressure regulators - no result"

There is only one fuel pressure regulator, as pictured in the link that you included in your last post. Can you take a picture of the one on your engine?
Please also take pictures of the two screws that you have been turning.

[Niko9]

This one is located underneath air intake, it has two hoses connecting to it


https://ibb.co/hsmM0bV

this one is located on the top and has three hoses connected, hose below returns to the fuel tank (not sure)


https://ibb.co/hXy5W0S

I would undo the bottom hex and then clockwise rotate with appropriate wrench

[Frank Reiner]

Originally Posted by Niko9

This one is located underneath air intake, it has two hoses connecting to it

https://ibb.co/hsmM0bV
this one is located on the top and has three hoses connected, hose below returns to the fuel tank (not sure)

https://ibb.co/hXy5W0S
I would undo the bottom hex and then clockwise rotate with appropriate wrench

The lower "regulator" is actually a damper, its purpose is to reduce pump pulsing noise in the fuel system. It is not intended to be adjusted. The "161" in the Bosch part number identifies it as a damper.
The upper device is the fuel pressure regulator, as identified by the "160" in the part number. The two fuel lines that connect to the sides of the regulator are the inlets. The center line at the bottom is the return.

Trace the fuel lines. Does the pressure line from the pump go first to the damper, and then to the fuel rail, or does the pressure line go directly to the fuel rail?

[Niko9]

Hi Frank,

What would be the next action once I check ?
how can I check if the fuel pump is actually releasing enough pressure ?
I am just worried because the pump does not seem to be OEM.. nor I. know whether the regulator works ..

[t walgamuth]

Just a comment perhaps off topic. The compression numbers don't look all that bad. If I could get it running I'd drive it.

[Niko9]

Originally Posted by Frank Reiner

The lower "regulator" is actually a damper, its purpose is to reduce pump pulsing noise in the fuel system. It is not intended to be adjusted. The "161" in the Bosch part number identifies it as a damper.
The upper device is the fuel pressure regulator, as identified by the "160" in the part number. The two fuel lines that connect to the sides of the regulator are the inlets. The center line at the bottom is the return.

Trace the fuel lines. Does the pressure line from the pump go first to the damper, and then to the fuel rail, or does the pressure line go directly to the fuel rail?

I just checked fuel line and it goes to damper and after it goes to the fuel rail.

https://ibb.co/4pvG99D Apologies for my artistic talents

[Frank Reiner]

Originally Posted by Niko9

I just checked fuel line and it goes to damper and after it goes to the fuel rail.

And that fuel line to the damper is the supply line from the pump?
I ask because there have been instances of the supply and return being interchanged. Supply pressure is sufficient to open the regulator from the return side; the engine will try to run, but not well.
You have indicated that you adjusted the valve clearances; hopefully slightly on the loose side.
Ignition timing should be set to 10-12 degrees BTDC w/o vacuum at idle (600-700 RPM). Timing should advance to 32-35 deg, BTDC w/o vacuum @ 3500 RPM.
There is an auxiliary air valve (AAV) which increases idle speed after a cold start. The idle speed will drop as the AAV closes, and is then adjusted with the idle air screw below the plenum between cylinders 2 & 3.

[Niko9]

Originally Posted by Frank Reiner

And that fuel line to the damper is the supply line from the pump?
I ask because there have been instances of the supply and return being interchanged. Supply pressure is sufficient to open the regulator from the return side; the engine will try to run, but not well.
You have indicated that you adjusted the valve clearances; hopefully slightly on the loose side.
Ignition timing should be set to 10-12 degrees BTDC w/o vacuum at idle (600-700 RPM). Timing should advance to 32-35 deg, BTDC w/o vacuum @ 3500 RPM.
There is an auxiliary air valve (AAV) which increases idle speed after a cold start. The idle speed will drop as the AAV closes, and is then adjusted with the idle air screw below the plenum between cylinders 2 & 3.

1 I have tried setting timing BTDC, inserted screwdriver and checked where the first cylinder was all the way up, it would not start by any cost, I had two loud bangs where the tube coming from air valve blew off the air intake..

2 I have checked injectors (OHM is good 2.9 3.0 on all of them.

** I took out air valve, put it in the hot water and it closed.. not sure to what extent it proves its good working order though..


3 is there any way to find out whether the wires conecting to sensors are not damaged?


4 Only way I was able to run car is that I set it 15 degrees after TDC (where the metal round attachment is on harmonic damper...

5 I am still confused whether I am doing this right, how my distributor does not have markings where the first plug should go in.. when I first did this it all worked fine, I thought I cracked enigma but now I am back at stage 1...