× Die Bosch D-Jetronic war 1967 die erste Großserien elektronische Einspritzung der Welt. - Bosch's D-Jetronic was the first mass-production electronic fuel injection.

Engine shaky after ignition but runs ok afterwards for w114 250CE

  • Achab90
  • Topic Author
  • Offline
  • New Member
  • New Member
  • Other countries
  • Mercedes-Benz W114 250 CE
More
17 Mar 2020 08:35 #13422 by Achab90 Other countries Mercedes-Benz W114 250 CE
Hi
I have now encountered a problem where my engine is shaky and seems to almost want to shut down after ignition. But after leaving it on for like 10-15 minutes, the engine is smoother and then there is no problem. The engine is less shaky and can say there is no prolem. Can you suggest where I should start investigating in my M114.980 engine for the Mercedes Benz w114 250CE? I have cleaned the fuel injectors already and changed a new pressure regulator.

Cheers
Archie

Please Log in or Create an account to join the conversation.

  • nordfisch
  • nordfisch's Avatar
  • Offline
  • Platinum Member
  • Platinum Member
  • Europe
  • Opel Diplomat 2.8 E
More
17 Mar 2020 12:05 - 18 Mar 2020 11:56 #13423 by nordfisch Europe Opel Diplomat 2.8 E

Achab90 wrote: ... my engine is shaky and seems to almost want to shut down after ignition. ...

Hi, I interprete what you wrote: After cold start (?)

Did you check tthe whole ignition? This is the first thing to do.
The early CE250 has a 'traditional' ignition with points and no electronic 'amplifier'. Therefor the points trend to have wear.

Second thing: The auxiliary air valve (AAV) gives additional air when the engine is cold. AAV not working means no extra air and low revs.

Check this. Does the AAV open < a liitle bit> when the engine is cold?

Regards
Norbert
Last edit: 18 Mar 2020 11:56 by nordfisch.
The following user(s) said Thank You: Achab90

Please Log in or Create an account to join the conversation.

  • Obelix
  • Obelix's Avatar
  • Away
  • Platinum Member
  • Platinum Member
More
17 Mar 2020 12:13 #13424 by Obelix
...sorry, that´s not correct, Norbert only the early 250 CE have the coil ignition, the later ones have also the transistorised ignition !

Greets Christian

Gruß
Christian
The following user(s) said Thank You: Achab90

Please Log in or Create an account to join the conversation.

  • nordfisch
  • nordfisch's Avatar
  • Offline
  • Platinum Member
  • Platinum Member
  • Europe
  • Opel Diplomat 2.8 E
More
17 Mar 2020 12:53 #13425 by nordfisch Europe Opel Diplomat 2.8 E
Thank you, Christian.
I have seen early CE250 ones only.
Correct it in my posting.
Regards
Norbert
The following user(s) said Thank You: Achab90

Please Log in or Create an account to join the conversation.

  • Volker
  • Volker's Avatar
  • Offline
  • Moderator
  • Moderator
  • Europe
  • Mercedes-Benz R107 450 SL, Mercedes-Benz W111 280 SE Cabrio
  • Dr-DJet repariert und sammelt alles! :-)
More
17 Mar 2020 13:22 #13428 by Volker Europe Mercedes-Benz R107 450 SL, Mercedes-Benz W111 280 SE Cabrio
Hi Archie,

several things can happen in a failing cold start

  • Auxiliary air valve could hang and not open. This is what increases rpm during warm run. On your car you can remove the small filter on AAV and check whether engine sucks in air there.
  • A ignition distributor can also hang. Verify ignition timing on ice cold engine. Both in dle and in 1500 rpm if you can. Also verify vacuum retard.
  • Verify resistance of engine temp sensor on ECU connector when engine is cold and when it is warm
  • Verify that cold start valve injects while cranking engine.

Where did you get a new pressure regulator? And how is fuel pressure right now?

Viele Schraubergrüße - best regards, Dr-DJet Volker
Alles über den Mercedes-Benz 107 SL/C in Sternzeit-107.de

This image is hidden for guests.
Please log in or register to see it.

Please Log in or Create an account to join the conversation.

  • Achab90
  • Topic Author
  • Offline
  • New Member
  • New Member
  • Other countries
  • Mercedes-Benz W114 250 CE
More
18 Mar 2020 09:08 #13437 by Achab90 Other countries Mercedes-Benz W114 250 CE
Hi
Thank you again for your reply.
Silly question but I think it's an appropriate time to ask. I am currently living in Thailand which is a tropical country with weather at around 30-40 degrees Celsius. I never paid much attention to the cold start valve because I had figured it was for Western countries with a lower temperature, especially during winter. So, is the cold start valve still necessary for me here?

I will have a look at all your suggestions and see the results.

For the new pressure regulator, it was very fortunate that I found one, although it cost around 240 euros. For the fuel pressure, I have not had the chance to change to the Pierburg you had suggested yet. Shipping has been delayed these past few months so have not received the part yet.

Please Log in or Create an account to join the conversation.

  • Volker
  • Volker's Avatar
  • Offline
  • Moderator
  • Moderator
  • Europe
  • Mercedes-Benz R107 450 SL, Mercedes-Benz W111 280 SE Cabrio
  • Dr-DJet repariert und sammelt alles! :-)
More
18 Mar 2020 11:35 #13438 by Volker Europe Mercedes-Benz R107 450 SL, Mercedes-Benz W111 280 SE Cabrio
Hi,

cold start valve should only work up to 35°C and only when cranking engine. So forget it in your case.

After replacing pressure regulator (and not MAP sensor) you should check and adjust fuel pressure.

Viele Schraubergrüße - best regards, Dr-DJet Volker
Alles über den Mercedes-Benz 107 SL/C in Sternzeit-107.de

This image is hidden for guests.
Please log in or register to see it.

Please Log in or Create an account to join the conversation.

  • Achab90
  • Topic Author
  • Offline
  • New Member
  • New Member
  • Other countries
  • Mercedes-Benz W114 250 CE
More
24 Mar 2020 07:36 #13485 by Achab90 Other countries Mercedes-Benz W114 250 CE
Hi Dr Jet
I checked the ignition distributor and ECU and have no problem with that. I am focusing on the AAS right now. So for it to function properly, does the AAS open after I start the engine? If I remove the small filter on the AAV and find out the engine sucks in air still, does that mean the AAV is working properly?
Thank you.
Regards
Archie

Please Log in or Create an account to join the conversation.

  • Achab90
  • Topic Author
  • Offline
  • New Member
  • New Member
  • Other countries
  • Mercedes-Benz W114 250 CE
More
24 Mar 2020 07:54 #13486 by Achab90 Other countries Mercedes-Benz W114 250 CE
Hi Norbert
Should the AAV open after I start the engine or should it have remained open before I started the engine?

Regards
Archie

Please Log in or Create an account to join the conversation.

  • Volker
  • Volker's Avatar
  • Offline
  • Moderator
  • Moderator
  • Europe
  • Mercedes-Benz R107 450 SL, Mercedes-Benz W111 280 SE Cabrio
  • Dr-DJet repariert und sammelt alles! :-)
More
24 Mar 2020 10:03 #13487 by Volker Europe Mercedes-Benz R107 450 SL, Mercedes-Benz W111 280 SE Cabrio
Hi Archie,

your AAV operates only on cooling water temperature. SO it must be wide open on cold engine. That means it should then suck in air. You can use a mirror to lookinto the are opening of the AAVs hose to manifold. You will see a slit that is partially covered by a piston. That should be open several mm even if engien does not run. It should close when engine reaches around 70°C engine temperature.

Viele Schraubergrüße - best regards, Dr-DJet Volker
Alles über den Mercedes-Benz 107 SL/C in Sternzeit-107.de

This image is hidden for guests.
Please log in or register to see it.

The following user(s) said Thank You: Achab90

Please Log in or Create an account to join the conversation.

  • Achab90
  • Topic Author
  • Offline
  • New Member
  • New Member
  • Other countries
  • Mercedes-Benz W114 250 CE
More
24 Mar 2020 10:16 #13488 by Achab90 Other countries Mercedes-Benz W114 250 CE
Hi Dr Jet
Is this the hole you are referring to (as in attached photo)?
Regards
Archie

This message has an attachment image.
Please log in or register to see it.

Please Log in or Create an account to join the conversation.

  • Volker
  • Volker's Avatar
  • Offline
  • Moderator
  • Moderator
  • Europe
  • Mercedes-Benz R107 450 SL, Mercedes-Benz W111 280 SE Cabrio
  • Dr-DJet repariert und sammelt alles! :-)
More
24 Mar 2020 12:43 #13489 by Volker Europe Mercedes-Benz R107 450 SL, Mercedes-Benz W111 280 SE Cabrio
Hi Archie,

no sorry, please look into hole where air filter is mounted.

Viele Schraubergrüße - best regards, Dr-DJet Volker
Alles über den Mercedes-Benz 107 SL/C in Sternzeit-107.de

This image is hidden for guests.
Please log in or register to see it.

Please Log in or Create an account to join the conversation.

  • nordfisch
  • nordfisch's Avatar
  • Offline
  • Platinum Member
  • Platinum Member
  • Europe
  • Opel Diplomat 2.8 E
More
24 Mar 2020 12:57 #13490 by nordfisch Europe Opel Diplomat 2.8 E
... and have a look at the information in Volker's compendium: https://oldtimer.tips/en/d-jetronic/aav
Regards
Norbert

Please Log in or Create an account to join the conversation.

  • Achab90
  • Topic Author
  • Offline
  • New Member
  • New Member
  • Other countries
  • Mercedes-Benz W114 250 CE
More
25 Mar 2020 04:14 - 25 Mar 2020 04:33 #13491 by Achab90 Other countries Mercedes-Benz W114 250 CE
Hi Dr Jet
This should be it right? So I will need to take off the filter before i see it. Just so that I am prepared to know what happens after I take off the filter, so is it correct to say that the AAS will suck in air when the hole is open and then stop sucking in air when the hole closes? Thank you again.

This message has an attachment image.
Please log in or register to see it.

Last edit: 25 Mar 2020 04:33 by Achab90. Reason: attached photo

Please Log in or Create an account to join the conversation.

  • Volker
  • Volker's Avatar
  • Offline
  • Moderator
  • Moderator
  • Europe
  • Mercedes-Benz R107 450 SL, Mercedes-Benz W111 280 SE Cabrio
  • Dr-DJet repariert und sammelt alles! :-)
More
25 Mar 2020 10:05 #13492 by Volker Europe Mercedes-Benz R107 450 SL, Mercedes-Benz W111 280 SE Cabrio
Hi Archie,

do not take it off. Use a mirror to peek into that hole on cold and hot engine.

Viele Schraubergrüße - best regards, Dr-DJet Volker
Alles über den Mercedes-Benz 107 SL/C in Sternzeit-107.de

This image is hidden for guests.
Please log in or register to see it.

Please Log in or Create an account to join the conversation.

  • Achab90
  • Topic Author
  • Offline
  • New Member
  • New Member
  • Other countries
  • Mercedes-Benz W114 250 CE
More
26 Mar 2020 05:11 #13496 by Achab90 Other countries Mercedes-Benz W114 250 CE
Hi Dr Jet
I apologize again for having to bother you with the same question, but I seem to be unable to find the hole you are referring to. I have attached a photo of the actual AAS in my car for reference. One end of the AAS is attached to the black hose. The other end with the flange is attached to the manifold of the engine. There is the pico-filter on the AAS. Hence, I don't know where to look unless I remove it from the engine. Thanks again.
Regards
Archie

This message has an attachment image.
Please log in or register to see it.

Please Log in or Create an account to join the conversation.

  • Volker
  • Volker's Avatar
  • Offline
  • Moderator
  • Moderator
  • Europe
  • Mercedes-Benz R107 450 SL, Mercedes-Benz W111 280 SE Cabrio
  • Dr-DJet repariert und sammelt alles! :-)
More
26 Mar 2020 09:50 #13498 by Volker Europe Mercedes-Benz R107 450 SL, Mercedes-Benz W111 280 SE Cabrio
Hi Archie,

remove the air filter and peek in there on 250 CE.

Viele Schraubergrüße - best regards, Dr-DJet Volker
Alles über den Mercedes-Benz 107 SL/C in Sternzeit-107.de

This image is hidden for guests.
Please log in or register to see it.

The following user(s) said Thank You: Achab90

Please Log in or Create an account to join the conversation.

Time to create page: 0.084 seconds
Powered by Kunena Forum