300CE - Starting Problem Update/Advise Pls

[fraz]

My 300ce has been a pig to start recently - the basic symptoms are when trying to start it will crank away but not fire - until i release my foot from the accelerator when it will then attempt to fire and chugg for a a short time then die. A big puff of smoke will often then be released via the front grille - coming out of the air intake/box. With many repeated attempts it will enventually start - when running it drives without fault. But when stopped it will again be a nightmare to get it running again.

So i have had a mechanic friend over to view the 300 again and he states ... 'that is definatley a timing issue, as tho it is 180 out. Basicly the timiming is firing in the wrong order eg. when the inlet valves are open' Please note he has NO experience of mercedes engines. Please can anyone advise if it would appear to be a timing issue? and also if replacing the crank position sensor would be the most sensible port of call to rectify this problem?

I have posted previously on this matter and was advised that 180 degree out 'tends to be only possible on non-inteference engines' so I am abot confused - can someone pls help me out.

Regards Fraz

 

[fraz]

can anyone confirm if the crank sensor would appear to be the most obvious thing to replace first - based on the above 'symptoms' Regards Fraz

 

[television]

If it runs when warm or hot then it will not be the crankshaft sensor, if it runs OK once it starts it will not be the timing.

Is it hard to start when hot

 

[fraz]

Thanks television - It can be hard to start when hot but not as hard as from a cold start when left for a while it will take at least 15 attempts to get her running. Does the '180 out' seem likely to you - obviously concerned by the smoke being chucked out the front when trying to start!

Would dearly like to get this prob rectified as she's sat on the drive not being driven at the moment.

Any help greatly appreciated

regards fraz

 

[television]

The distributor cap shorting will make the car blow back through the intake air box is it can make a cylinder fire when on the intake stroke, that makes the popping sound as well.

look inside for any black tracking lines

 

[Legoman]

id agree with malcolm , check the dizzy cap and arm , its ignored so often on these cars as there hidden from view , it sounds like an ignition fault of some type , a process of elimination is the only solution , work your way from the sparkplugs back through till the fault shows itself.

 

[MotardMan]

My 300ce has been a pig to start recently - the basic symptoms are when trying to start it will crank away but not fire - until i release my foot from the accelerator when it will then attempt to fire and chugg for a a short time then die. A
Regards Fraz

Couple of things. Why is your foot on the accelerator when cranking it? DON'T put your put on it, until it has fired, when starting from cold.

The smoke, could be unburned petrol fumes blowing out of the airbox when the engine spits back. Take a plug out after cranking it and see if it is wet or smells of fuel. I'd also buy a rotor arm and dizzy cap from a dealer and replace those as they can be troublesome. This sounds like ignition, and not timing, if it were 180 deg out you'd have some very serious running issues once started.

Let us know how you go?