[Joelll]

My Merc W114 280e 1974 model has stopped. Started to idle rough, hard to start and now wont fire at all. There is spark, the fuel pump is working and have fuel pressure.
Can anyone help with what the problem could be?
Thanks

 

[mbbuff]

A 280E is a 123 chassis, and is fuel injected. Is this a carburated 280C? If it is, it may be the float in the Solex 4 bbl. carb. Mine went bad over time, and became harder and harder to start, would die sometimes, and load up (flood) at idle. I adjusted (lowered) the float level a few times, but that is only a temporary fix. Floats are available and relatively inexpensive, also quite simple to replace. Just be sure you adjust it to specs. Also, check the choke for proper operation before you go any farther in troubleshooting. The choke is primarily electric, and if unplugged or inoperative, the choke will not unchoke properly.

 

[Joelll]

No my car is a 1974 280E fuel injected. Symptoms started quickly from hard to start one day to stop the next after running perfectly for many years. Could this be the crank sensor? Are they known to have problems? The motor winds over freely, and could the engine balance slip or are they on keyways?
Fuel supply seems to be ok as the plugs are wet, spark is strong and all fuses seem to ok. This is this end of my mechanical knowledge can anyone help?

 

[Eirik 400 SE]

A 280E is a 123 chassis, and is fuel injected. Is this a carburated 280C? If it is, it may be the float in the Solex 4 bbl. carb. Mine went bad over time, and became harder and harder to start, would die sometimes, and load up (flood) at idle. I adjusted (lowered) the float level a few times, but that is only a temporary fix. Floats are available and relatively inexpensive, also quite simple to replace. Just be sure you adjust it to specs. Also, check the choke for proper operation before you go any farther in troubleshooting. The choke is primarily electric, and if unplugged or inoperative, the choke will not unchoke properly.

Wrong There was a 280E with the M110 engine.. A W114 then..
http://www.strichachtclub.de/c_infos/c_infos_daten.php
It can be many things.. The warm-up regulator, the cold-start-nozzle, low voltage on the spark, etc etc..
Are the plugs wet ? Do the smell gas ?
Are they black ? White ? brown ?
Are the spark equally good on all plugs ?
Have you checked that ALL plugs get a "signal" ? Moving the strobe-lamp-sensor from one plug-cable to the next ?

 

[Joelll]

Thanks Eirik 400 SE,
Yes the spark plugs are wet and do smell of gas, and they are black.
Haven't had a chance to try your other ideas yet.
I have found melted wires to crank sensor, repearing that now
I'll get back to you,
Aussie Merc

 

[mbbuff]

You're right, and as I said the 280E is a 123 chassis, not a 114 chassis as he indicated.

 

[drew56cus]

mbbuff, I have to rebuff you (pardon the pun) - Australia got w114 cars with the M110 motor, both fuel injected (280E) and carbied (280).
Joelll, sorry I cannot add much more as I had the mis-pleasure of trying to get an M110 going in a W123 and it was a bugger. Vacuum lines, lots of sensors, many things associated with the injection and ignition that can go wrong and are in horrible places to get to. Hopefully Mercmad6.3 will post a response as he got the M110 going for me.
Cheers, Drew in Brisbane

 

[popuptoaster]

Mines a w114 280ce, i had a duff coil in mine that made it run bad, needs the proper mercedes coil cos of the weird 18v transistorised ignition.

 

[mbbuff]

Sorry Drew, you are correct. There are too many different .XXX after the W114 to keep up with. I stand "rebuffed".

 

[Joelll]

My 280 runs again.
After cleaning the cold start valve, taking all the spark plugs out to let the motor dry out for a day i left the cold start valve disconnected. First touch of the key it goes.
Thanks for your help.
P.S on the ECU there is an adjustable dial can anyone please tell me what this is for and if i can adjust mixture from there?

Thanks

 

[Grubeguy]

The dial on the ECU controls fuel/air mixture...

 

[bobtherebuilder]

Clockwise to give richer mix,anti clockwise weakens.

 

[Eden John]

Nice post. I am learning alot through people's reply. I am trying to learn about cars and parts and how each parts works. Atleast if i get my own car and if died or have trouble i can do something to fixed it. Thanks

 

[Master09]

mbbuff, I have to rebuff you (pardon the pun) - Australia got w114 cars with the M110 motor, both fuel injected (280E) and carbied (280).
Joelll, sorry I cannot add much more as I had the mis-pleasure of trying to get an M110 going in a W123 and it was a bugger. Vacuum lines, lots of sensors, many things associated with the injection and ignition that can go wrong and are in horrible places to get to. Hopefully Mercmad6.3 will post a response as he got the M110 going for me.
Cheers, Drew in Brisbane

Ahem.
Please observe gentlemen, the picture below. My W114 280E. M110 D-jetronic.




Another thing, where is the ECU dial??? My fuel is running way too rich...