Shake Shake on startup W124 230E

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imbck666

Active Member
Joined
May 10, 2009
Messages
272
Location
London
Car
Mercedes W124 230E Saloon (SOLD), W210 E200 (WRITTEN OFF), W210 E240 2001 Facelift, W211 E220 cdi 07
Hi all,

Had a 'problem' if you call it since I bought my 230E 124.

M102 engine if its going to help...

Here goes..

On startup, sometimes like 7 out of 10 times I turn the key and the car starts up with a shake shake shake but I mean strong shake... its like someone is shaking the car from outside..
Shakes 3 to 4 times and economy meter goes to middle.. then within 1.5 to 2 seconds shakes disappear and car settles down to a steady idle..

I will post a video when I get a chance but just to add.. the car doesnt stall at all.. has steady idle.. doesnt die on startup and always starts up on first turn of key..

Just a summary:

Key in, turn key .. cranking as normal.. engine fires, economy meter goes to middle with rpm around 500-600 shaking happening.. shake shake shake shake.. then rpm 700-800 settled down, economy meter back to low end and car idle settled..

this is all happening in a time span of 2-3 seconds..


Just to add.. Plugs are new, HT leads are brand new changed around 6 months ago and are BOSCH original..

Could it be cold start sensor/valve?
Dizzy cap? or rotor arm?



Thanks to all replies from now
 
Hi
yes, get the dizzy checked, my 230TE got a bit like that and it was damp/gunge in the dizzy and rotor - the knackered engine mount made it worse though, so do check your engine mountings while you're on it!

cheers
 
thanks for that.. anything else?
 
anyone?
 
thanks for that.. anything else?


Hi

Do you experience the same problems when the engine is at working temp?

eg. after 15-20min drive?

mazza
 
no not at all.. no problems with idle or anything.. its merely on startup.. thats it.
Ive driven the car to Netherlands.. Turkey.. etc.. no problems..
Had the car for 2 years.. had the problem ever since.. never stalled or anything.. just shaking on startup
 
no not at all.. no problems with idle or anything.. its merely on startup.. thats it.
Ive driven the car to Netherlands.. Turkey.. etc.. no problems..
Had the car for 2 years.. had the problem ever since.. never stalled or anything.. just shaking on startup


Hi

identifying problems with the Bosch KE Jetronic injection is a process of elimination...and even using this sytem, it can seriously drive you crazy...he he!!

As per previous posts, check the dizzy and rotor arm, you can get condensation build up which can cause symptoms as described by you.

when did you last have the idle adjusted, by the means of adjusting the air/fuel mixture using a 3mm Allen key?

the initial rpm's look a bit low...so maybe you are not getting enough fuel when performing a cold start. This could be caused by a faulty Cold start injector or its harness.

The cold start injector is activated by the ECU via the coolant temperature sensor.

ps- Please dont just stick a 3mm Allen key in the mixture control unit and go wild...its a very delicate control unit and requires precise adjustment, best method is to use a CO exhaust analyzer.


mazza
 
it could be that one or more injectors are leaking a bit of petrol into the cylinders when engine is off overnight say, and that means that mixture is rich on start up in those cylinders, and clears as the petrol is burned off.
 
hmmm... now we are talking..

as for the injector leaking as kth286 said.. im not sure as it doesnt happen after a long park up.. it sometimes even happens when engine is warm.. :S
i thought maybe a cold start sensor/valve...

could it be the idle control valve?

could it be spark plug gaps? as they are currently set to 0.8mm.. would it help if i set them to 1.0mm?

also to add.. checked the dizzy cap - no condensation or water, contacts look a bit old, cant even see the brass.. so will definitely change that regardless

all replies up to now are much appreciated! :)
 
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would it do this if it was out of tune? or mixture not adjusted properly or even timing a little out?

another question is how easy is it to change the injectors on an M102 engine i reckon i can tackle it as i am very mechanically minded (commercial pilot and aeronautical engineer =] ).
Does anyone have a how to guide for m102 injector change or guide ?

I think I will just change all the injectors to new Bosch ones anyway.
 
I think I will just change all the injectors to new Bosch ones anyway.

It may not need that amount of extravagance.

You could pull out the injectors and with the supply pipes still attached and ignition on so that the fuel pressure is up to max, can check if any injectors
are leaking, and just replace (or get cleaned) those.
 
Sounds as if the cold start valve could be a candidate as mazza suggested -- on earlier cars its powered via the dreaded fuel pump relay- and these do go faulty. A way to check would be to remove the valve temporarily and direct its output via a tube into a suitable receptacle. Plug off the manifold orifice temporarily and try starting with the engine stone cold - the valve should run for about 15 secs?? irrc
 
Can I not just take out the cold start valve and leave its space empty then start the engine? Also, where is the cold start valve on the m102 engine?
 
Leaving the cold start valve off means there's a large hole in the inlet manifold meaning the car may not start- certainly run weak- doesn't need much- a suitable tightly fitting rubber plug will do. The cold start valve 44 is located on the inlet manifold and fed by a short pipe from the fuel distributor body fuel gallery.
 
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hmmm...

" it sometimes even happens when engine is warm.. "

could it be spark plug gaps? as they are currently set to 0.8mm.. would it help if i set them to 1.0mm?

Hi

ah!! if you are having the same problems when the engine is at working temperature, i would rule out the cold start valve.

you mentioned that you have replaced the HT leads/spark Plugs, Please check that only one of those items is fitted with "resistors". if both HT leads and plugs are fitted with resistor, it can cause a very low spark on some spark plugs, I had a problem like this in the past.

it sounds like the shaking is been caused by 1 or 2 cylinders are not firing properly, hence the massive vibration as described by you.

I'm not sure about the correct idle rpm for your engine...but should be something like 750-800rpm.

check the resistor situation and if you have the correct set up, you might just need a mixture tune up.

mazza
 
i think,u must check fuel pressure regulator(FPR) and electro hidraulic actuator(EHA) differential pressure,,
if hot condition it's between 0,4 bar diferential pressure of EHA, and statics condition is 0,5 bar..
first step u must have a pressure gauge, and then upper and lower in fueldistributor must be adjusted.
 
have you checked the OVP fuses?
Im asuming you have the 2 fuse version as i did on my 230E.
Behind the batter there is a cover, remove it.
Then you will see a black cover over a relay - remove the cover to reveal your ovp and fuses. he fuses are fine - try running your car whilst having the cold start injector disconnected.
 

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